ISSN 0704-3716
CANADIAN TRANSLATION OF FISHERIES AND AQUATIC SCIENCES
No. 4723
Studies of aquatic mammals. IV. Food of the white or beluga (Delphinapterus leucas) of the St. Lawrence river.
by V.D. Vladykov
Original Title: Etudes sur les mammifères aquatiques. IV. -Nourriture du Marsouin Blanc ou Béluga (Delphinapterus leucas) du fleuve Saint-Laurent
From: Contrib. Dep. Pech. Que. (17): '9-131, 1946
Translated by the Translation Bureau Multilingual Services Division Department of the Secretary of State of Canada
Department of Fisheries and Oceans Scientific Information and Publications Branch Ottawa, Ont.
1981
184 pages typescript THE FEEDING HABITS OF THE WHITE WHALE
Ministry of Fisheries, Québec C ^ i4^^, q7,^j MINISTRY OF FISHERIES
PROVINCE OF QUEBEC
The Hon. Camille-E. Pouliot, M.D. Arthur Labrie, D.Sc.
Minister Deputy Minister
STUDIES OF AQUATIC MAMMALS
IV. -FOOD OF THE WHITE WHALE
OR BELUGA (DELPHINAPTERUS LEUCAS)
OF THE ST. LAWRENCE RIVER
• by
Vadim-D. VLADYKOV; Ph.D.,
Biologist
Contribution of the Department of Fisheries
Québec, - No. 17
QUEBEC CITY
1946 TABLE OF CONTENTS PAGE
Preface 4 Introduction 6 Collected Data 9 The Digestive system of the Beluga 17 Technique for the analysis of stomach contents 26 Enumeration of individual organisms - Species identification
Alimentary regimen of the Beluga 47 General considerations - Feeding mode
Composition of food 58 Fish: - Caplin.- Launce.- Sculpin.- Tomcod.- Flounder.- Sturgeon.- Haddock.- Smelt.- Other fish.
Invertebrates: - Clam worm.- Squid.- Octopus.- Lamellibranchia.- Gastropoda.- Decapoda.- Amphipoda.- Oter groups.- Seasonal variations.- Regional variations.- Correlation between the abundance of food and the thickness of blubber.
The Beluga and commercial fish 111 Cod in Alimentation of the Beluga:- Identification.- Size and number of cod.- Variations according to the sex of the Beluga.- Seasonal variations.- Summary.- Salmon in the alimentation of the Beluga.- Herring and Eel in the Alimentation of the Beluga.-
Is the Beluga responsible for cod fishery fluctuations? 133 General considerations.- Size of Beluga and cod. - Seasons and centres of concentration.- Vertical distribution. - Cod fishery fluctuations in the St. Lawrence.
Conclusions ...... 148
Bibliography ...... 153
Appendix ...... 158
0 - 4 -
PREFACE
The fisherman has a keen sense of observation which guides him in the search for fish, in navigation and in averting danger. His judgment is based on the simple principle that similar phenomena fore- tell similar events. By applying this natural grasp of things to fluctuations in cod fishing, for example, he is most likely to attribute bad fishing years to visible and tangible factors such as the presence of dogfish or White Whales. To say that cod fishing is poor in places frequented by whales is true; however, that they are responsible for the condition is not necessarily so. The biologist would ask why an animal like the whale occasionally leaves its natural habitat to invade other less frequented areas. Is it drawn by commer- cial fish like cod, which in turn flee before this strange invasion, or is the phenomenon more generalized and complex? This is what the author has attempted to answer, at the request of the Québec
Department of Fisheries, in his study of St. Lawrence Gulf and River
Beluga.
In his research about this mammal, Dr. Vladykov has accumulated a great deal of biological and practical data. He and Dr. Bonin published a first article, "La Peau du Marsouin blanc ou Béluga"
(Delphinapterus leucas)", in The Canadian Naturalist in 1940. In the same publication in 1943, "A Modification of the Pectoral Fins in the
Beluga from the St-Lawrence River" appeared. It would have been unfortunate if the author's numerous other observations on this animal's natural history were not compiled in a practical handbook for - 5 -
fishermen, students and teachers. That is precisely what the author did in 1944 by publishing "Chasse, biologie et valeur économique du Marsouin blanc ou Béluga (Delphinapterus leucas) du fleuve et du golfe
Saint-Laurent". Ultimately, the goal of this study was to determine the whale's habits, or rather, what draws it to our important commercial fish. To this end, the author now presents "The Feeding Habits of the White Whale or Beluga (Delphinapterus leucas) in the St. Lawrence River".
An extensive knowledge of aquatic animals was required for accurate identification of the species based on residue found in the stomach bolus of the Beluga. The identification of crystallins, • otoliths, bones or the remains of specific parasites reveals great patience, work and knowledge. This study, with its data, maps, tables and illustrations is a good complement to the preceding publication, "Chasse, biologie et valeur économique du Marsouin blanc".
In addition to the specific goal of developing legislation to protect our cod fisheries, this study may also encourage full use of
the White Whale for sports and commercial purposes and contribute valuable information to this field of knowledge.
ARTHUR LABRIE, D.Sc., Deputy Minister of Fisheries to Québec City, December 21, 1946 - 6 -
INTRODUCTION
From year to year, the abundance of fish is variable, often
subject to pronounced fluctuations. In the case of commercially
valuable fish, such as cod, annual fishing variations must be
considered natural phenomena caused by periodic variations in the
aquatic environment. Thus, fluctuations in the abundance of different
species are cyclical: good fishing years are periodically followed by
poor yields and vice versa.
For cod fisheries, where fluctuations are particularly
pronounced, the reduction in catches causes the fisherman who is
unaware of the real cause, to worry about the future of his industry.
In the search for causes, the White Whale has become a scapegoat.
This is why a few years ago, Québec fishermen asked for Ministry of
Fisheries assistance in destroying the Beluga (Vladykov, 1944).
In order to see if the Beluga is indeed a dangerous destroyer of
cod, salmon and other important fish, we have undertaken the first
detailed study in Québec of the alimentation of this Cetacean. We
have also studied the possible influence of the White Whale on the
periodic variations of cod fishing over the years. The results of
this research constitute the substance of this work.
A number of people have contributed to this study, in addition
to the Department of Fisheries experts.
0 - 7 -
Dr. Paul Bartsch, Curator of Mollusks, U.S. National Museum Washington, D.C. and Dr. Herald A. Rehder, of the same institution,
kindly identified certain Cephalopods of the St. Lawrence River.
Dr. William J. Clench, Curator of Mollusks, Museum of
Comparative Zoology, Harvard College, Cambridge, Massachusetts, and Dr. Richard W. Foster of the same institution, were kind enough to
identify the mollusks from the Beluga stomachs.
Dr. Georges Préfontaine, director of the Institute of Biology of the University of Montréal obligingly granted the use of one of the • Institute's laboratories. Dr. Guy Prévost, then a medical student at the University of Montreal, assisted us in collecting the food of the Beluga in the field. Messrs. Vianney Legendre and Charles Gauthier, then students at the same university, assisted in sorting the stomach contents. Many St. Lawrence whalers provided us with their dedicated cooperation.
To the Department of Fisheries experts and to all the people
mentioned above, the author would like to express his heartfelt
gratitude.
The photographs were taken by Dr. Prévost (Nos. 3 and 6-8), the 111110 author (Nos. 4, 5, 17, 18 and 23), and the Montréal company e - 8-
La Photographie Générale Enregistrée under our supervision (Nos. 9, 10, 12-15, 19-22, 26, 28-30 and 32-37). With the kind permission of the administration of The Canadian Naturalist, some negatives were
used from previous articles which appeared in that publication: No. 11 (Vladykov, 1941) and Nos. 24 and 25 (Vladykov, 1936). Figures 1 and
42 appeared in our previous publication on the Beluga (Vladykov, 1944). Figures 1, 16, 27 and 35 were drawn by Miss Germaine Bernier of the University of Montreal.
e
- 9 -
O COLLECTED DATA
The study of the alimentation of the Beluga is based on data
collected during 1938 and 1939 in the St. Lawrence River at.the three main locations shown in Figure 1. Beluga are caught by three different methods: on the Manicouagan Bank, they are pursued by power boats; at Les Escoumains, by sailing canoes; and near Rivière-Ouelle, in a Beluga weir. Details of these hunting methods are given in a previous publication (Vladykov, 1944).
e '
a • e.,..... t › ••, % SAIL SES o SEPT-ILES X 1 r ›
POINTE -0 -110117 ••• • e SAIE COMEAU E LEMEL .. › 4 CAP CHAT —I-7. ••---. 8E73841817ES* * WMUE 4 4 4 8, , , LES ES • 818014 R11400181
TA S O USSA •700Is-PISTOLES ,
RIVCERE-ou-Lour
IIALSAIE •
ItAIE-, 187PAUL 0IVI[RE-OUEL.LE C& tr ep AUX 20 0 '• 40 OUDRES Échelle:eomilles auvoiJee
S d • 8 • 87
FIGURE 1.- Schematic map of the St. Lawrence River indicating where Belugas are caught. 1- Manicouagan Bank in the vicinity of Pointe-Lebel; 2- Les Escoumains; • 3- Rivière-Ouelle - 10 -
TABLE I.- Detailed stomach contents of adult Beluga (over 10 feet) taken in 1938 on the Manicouagan Bank.
Stomachs with food Month examined Stomachs Empty with Stomac hs Tot al in the on sand laboratory location
MALES
June 9 1 - 2 12 July 10 - - 8 18 August 16 3 - 5 24 September 5 1 - 6 12
Total 40 5 - 21 66
FEMALES
June - - - 2 2 July 8 - - - 8 August 11 5 1 4 21 September 10 - - 4 14
Total 29 5 1 10 45
0 • - 11 -
We used the following method to collect the Beluga food. After
beaching and skinning the animal, the carcass was positioned on its
right side using tackle, when necessary, to turn it. It was then cut
on the left side in the second or third intercostal space with an
axe. Once the skin was cut, a butcher's knife was used (Fig. 6).
Then the esophageal region of the stomach was removed and opened right
up to the esophagus itself (Fig. 7). When food was present, the
stomach contents were preserved in 10% formol. This concentration was
necessary to arrest the digestion of the food samples.
0 0 - 12 - TABLE II.- Detailed stomach contents of young Beluga (under 10 feet), taken in 1938 on the Manicouagan Bank.
Stomachs Stomachs Stomachs Empty Month with milk with other with sand Stomachs Total food
MALES
June - 3 - 1 4 July 2 3 - - 5 August - 1 - - 1 September 2 1 - - 3 Total 4 8 - 1 13
FEMALES
June - 1 - - 1 July 1 3 - - 4 August 1 2 2 1 6 • September 3 5 - - 8 Total 5 11 2 1 19
to - 13-
O TABLE III.- Detailed stomach contents of young Beluga (under 10 feet), taken in 1939 in the St. Lawrence River.
i Stomachs Stomachs Empty Month with milk with other Stomachs Total food
di cr 9 ecr ?. 9 ee
LES ESCOUMAINS June - - 1 - .. 1 July - - 3 1 .. 4 August 1 1(1) - - •• 2
RIVIÈRE-OUELLE
October 1 1 • Total 1 1 4 1 1 8 (1) This specimen was taken on the Manicouagan Bank
- 14 -
TABLE IV.- Detailed stomach contents of adult Beluga (over 10 feet), taken in 1939 in the St. Lawrence River.
Stomachs Empty Month with food Stomach Total 00 d (ir 00 e 6 and 0 0 + + + + + +
LES ESCOUMAINS June 2 4 - - 6 July - 4 - - 4 August - 2(1) - - 2
RIVInE-OUELLE
October - - - - - November 1 1 - - 2 • Total 3 11 - - 14 (1) One of these specimens was taken on the Manicouagan Bank.
In 1938, we collected 143 Beluga, all from the Manicouagan Bank
in the vicinity of Pointe-Lebel (Tables I and II). In 1939, 22 other specimens were collected, including 17 from Les Escoumains, 2 from Pointe-Lebel and 3 from Rivière-Ouelle (Tables III and IV). This material may be broken down as follows:
Stomach contents Number of stomachs
empty 34 sand only 3 milk (nurslings or calves) 11 food other than milk 117 e • - 15 -
Among the stomachs with food, 10 were examined on location
without detailed notes on their contents. The other 107 were studied
in the laboratory as carefully as possible. The results of the
analyses of the contents of each stomach are given in Tables XXIV-XXXV
in the Appendix.
TABLE V. - Detailed stomach content of all Beluga (young and
adult) taken in 1938 and 1939 in the St. Lawrence River.
Stomachs with other food Stomachs Stomachs with Examined Examined with Empty Month milk in the on sand Stomachs Total lab. location is June - 20 1 - 5 26 July 3 32 - - 8 43 August 3 32 8 3 10 56 September 5 21 1 - 10 37 October - - - - 1 1 November - 2 - - - 2
Total 11 107 10 3 34 165
• • - 16 -
•
FIGURE 2. - Interior view of the Beluga's compartmental stomach. Numbers 1,2,3,4 and 5 indicate the different parts of the stomach: 1- esophageal region; oe- esophagus; 1- liver; hd- hepatic duct; pd- pancreatic duct; d- duodenum (asper Watson & Young, 1880).
• - 17 - THE DIGESTIVE SYSTEM OF THE BELUGA
In order to better understand the particularities of the
Cetacean's diet, a few general points about the anatomy of its digestive system are in order.
The numerous teeth of the Beluga serve only to hold the prey
which is swallowed whole (1): they are unsuitable for cutting or chewing the food. In addition, the Beluga is distinguished from
Terrestrial mammals by the absence of tonsils and the uvula. Salivary
glands are very probably absent as well. (Watson & Young, 1880, p.
397)
(1) Arsenyev (1939 p.36) made similar observations about Beluga in the North Pacific. - 18-
O
s
interior of the Beluga's compartmental FIGURE 3. - Photograph of the sections as numbers correspond to the same stomach. The 30 inches long. those in Figure 2. The ruler above is
• - 19 -
The esophagus, about 12 inches long in an adult (1), leads to
the stomach which is compartmentalized like those of ruminants.
According to the observations of Wyman (1863, pp.606-607) and Watson & Young (1880, pp. 399-401), there are five compartments (2) (Figures 2-5). The dimensions of these compartments vary:
Compartment Length (in.) Diameter (in.) Length (in.) Diameter (in.) 1st 21 12 11 9 2nd 18 5 12 41 3rd 3 11 3 21 4th 7 3 5 21 5th 18 3 13
Length of 10 feet (e) (3) 8 feet, 71 1 nches the Beluga (9.) (3) 411, Authors Wyman (1863,p.607) Watson & Yo ung (1880, pp. 3 99-400)
In our observations, the first compartment of 621-inch young Beluga (#317) was 5 inches long and 5 inches wide. In a 131-inch specimen (#310), the first compartment was 8 inches long by 3 inches wide and the second was 11 by 3 inches.
(1) According to the observations of Dr. Prévost, the diameter and length of the esophagus were 2 and 141 inches respectively in the 131-inch Beluga (N o 310). (2)The stomachs of certain other Cetaceans (Ziphiidae) are divided into as many as 14 sections (Howell, 1930, pp.313-314); (Kellogg, 1938, pp. 655-658). (3) The symbol erepresents the male sex, y the female sex. e -20-
The compartment of primary importance to our present study is
the first, which we call the esophageal region. This section, which
is simply a dilation of the esophagus, is consequently devoid of
glands. It has a very thick muscular wall and an internal surface
covered with a rough cuticle that forms numerous folds (Figures 2-5).
This part of the stomach is least attacked by digestion and thus only
the stomach bolus of this compartment can be used for identification
of ingested species.
We observed that the capacity of the esophageal region of a
138-inch dead Beluga U100) was 5 gallons. In a living animal, of
• course, this compartment could be dilated even more by the ingestion of food.
The other four parts of the stomach are "chemical compartments"
which secrete gastric juices. Boluses taken from any of these
sections were digested to the point that their components could not be
identified.
0 • - 21 -
•
FIGURE 4. - Exterior view of the compartmentalized stomach of the
Beluga. The numbers correspond to the sections marked in
Figure 2.
The intestinal structure of the Beluga is quite simple: there
is no small intestine, no colon, no caecum (Barclay & Neil 1821;
Watson & Young, 1880; Struthers, 1896) (1). In specimen #308, the
diameter of the intestine varied from 3 inches near the duodenum to
1 1/5 near the anus.
0-) For more details about the structure of the digestive duct of the Beluga, refer to the authors mentioned above.
• - 22 - As shown below, the Beluga intestine is of considerable length.
Beluga Length of Ratio of the length of Authors intestine the Beluga to the length in. length of its ft. in. sex intestine Barclay & Neil (1821) 13 4 cr 85•1- 1:6.3 Watson & Young (1880) 8 7-1. Q 54 1:6.3 Struthers 12 5 91 1:7.3 (1896) # 4 (1938) 8 *Pi e 75 1:8.8 # 93 (1938) 10 10 ? 63 1:5.8 #308 (1939) 11 6 75 1:6.5 ? •
FIGURE 5. - The first four stomachal regions of the Beluga are opened. The food (squid) is visible only in the first (esophageal) • region where it is only slightly broken down by digestion. - 23 -
FIGURE 6. - An incision is made with a butcher's knife on the left side of the Beluga in order to facilitate the removal of the stomach.
FIGURE 7. - The esophageal region of the Beluga is drawn out through the incision.
The body temperature of the Beluga is quite high: the intestine
of a 7E4-inch young male (#301) registered 91.4° F (33 ° C) 2 hours after O - 24 -
death, and that of a 138-inch pregnant female (#308) registered 96.5 ° F
(35.8 ° C) under similar conditions (1).
The Beluga's digestion is probably very active because of the anatomy of its stomach and its high body temperature. This allows the animal to fatten quickly in good seasons and thus to survive on its
blubber reserves when food is scarce. When the Beluga arrives at
Rivière-Quelle in the spring, it "is lean and starving.. , and it gorges itself with such voracity that, in eight to ten days, it
acquires 5 to 6 and sometimes even 8 inches of blubber (Casgrain, • 1863, pp. 9-10). Place Manicouagan Les Escoumains Rivière-Ouelle Grand Bank Total
Year 1938 & 1939 1939 1939
def Qme), Sex Newborn calf - 1 - - 1 Blue calf 5 8 2 1 - - 16 Greyish- white calf 9 11 1 2 - - 23 White Whale (adult) 34 22 2 7 1 1 67
Total 48 41 6 10 1 1 107
(1) According to White (1891, p. 385), the porpoise (Phocaena) is also 96 ° F. Laurie (1933, p. 366) recorded 95 ° F for the Balaenoptera. e - 25 -
O The physiology of the Beluga's digestion is unknown. Some information however, is given by Morimoto (1921) and Takata (1932) on the Balaenoptera borealis (1).
•
(1) Babkin (1944) has an excellent summary of present knowledge of digestion and particularly of the digestive gland secretion • mechanism of terrestrial vertebrates. - 26 -
TECHNIQUE FOR THE ANALYSIS OF STOMACH CONTENTS
The study of Cetacean food demands special techniques because of
the enormous quantity of ingested food, often made up of small
species. A mass of tiny "shrimp" known as "krill" ( Euphausia
superba) weighing more than one ton was found in the stomach of a
finback whale ( Balaenoptera musculus) (Peters, 1937, p. 13)
TABLE VII. - Detailed stomach contents of newborn Beluga calves taken in 1938 and 1939
No Sex Date Length Colour Contents of Stomach in. cm. Food Parasites
43 20.VII.38 61 155 brown milk absent 47 cf`' 22.VII.38 62 158 brown milk absent 51 d"' 28.VII.38 62 158 brown milk absent 317 c^ 3.VIII.39 62z 159 brown milk absent 117 ^ 2.IX..39 63 160 brown milk absent 86 20.VIII.38 64 163 brown milk absent 131 10.IX.38 64 163 brown milk absent 122 e 8.IX.38 66 168 brown milk absent 142 23.IX.38 73 185 brown milk absent 130 10.IX.38 76 193 brown milk absent 301 21.VI.39 782 199 brown caplin present 73 6.VIII.38 782 199 brown absent present 319 27.VIII.39 80 203 bluish milk absent 97 30.VIII.38 83 211 bluish sand present
• - 27 -
O The bolus of the Beluga's esophageal region is the least attacked by digestion and thus can be used for identification of
ingested species. Even in this part, the food is often ground up by the wall muscles as well as by swallowed sand and pebbles (Figures 8
and 9) (1). Doubtlessly, the numerous parasitic worms (Anisakis
simplex) present in the stomach also aid in digestion (2), and gastric juices from the second and perhaps other compartments can probably
enter the esophageal region as well. All of these factors make it difficult to analyse the Beluga's food. •
(1)When there are large accumulations of such inorganic matter, Beluga can probbly get rid of it by vomiting. (2)We have removed as much as a gallon of these nematodes from a stomach (Vladykov, 1944. p. 118). A detailed description of these parasites is given by Lyster (1940). to - 28 - TABLE VIII.- List of fish taken from the stomachs of Beluga captured in 1938 and 1939 in the St. Lawrence River.
Species fo und in English Scientific French name name name No. of Beluga stomachs Nos
Aiglefin Haddock 65,10Ea' ' , Melanogrammus 2 316,312 Anguille de roche Eelpout aeglefinus 2 3)6 Anguille de roche Blenny. Zoarces anguillaris 1 Baboune Sea snail Blenniidé .. . 52, ,55, 69, 83 Neoliparis ; ; 4 54 Voir l'Appen4iéè: Caplin . atlàtticùà ::?, _; Greenland sculpin Mallotùs. nillosus Voir l'Appendice Myoxbcephàl, 33 Staghorn.sculpin groentandiciis: 89, 127 Gymnocantièus :` 2 99 Smelt,:, ériçus is 1 P . ^^ " Sturgèôn Osmerus nitirdaz: 96, 314, 3'.6 Acipenser;,;._ 3 85,316 Herring-, bcryrhynçhüs : , 2 Sea"lampréy Clupea h6rëiïgûs 2 70,111 Petranyaon Sind launce , marinua.' : 58 Voir l'Appendite rlmmodytes', ; 18 Voir l'Appendic, Tomcod americanus 1 11 Nfôrüè barbue Hake Microgadus tomcod Morue commune Cod Urophycis chuss 1 45 ^Voir l'Appendi(e Morue de roche Greenland cod Gadus callarias Plie Witch {lounder. . Gadus ogac 1 336 Glyptocephalus 5 111, 112, 113, Plie Smooth flounder cynoglossus 127, 132 Liopsella pulnami Plie Winter flounder 7 71, 74, 85, 94, 99, Pseudopleuronectes 103a, 111, 112, 139 americanus 1 304 Foule d'eau Lumpfish Qyclopterus lumpus 1 S9 Raie Prickly skate 2 92, 121 Raie Smooth skate Raia radiata 3 61,70,91 Raie Skate Raja senla 1 304 Saumon Salmon Raia sp. P Salmo salar
• - 29 -
ENUMERATION OF INDIVIDUAL ORGANISMS
Although skeletal fragments and pieces of flesh from fish and invertebrates are sometimes found in great numbers, specimens taken from Beluga stomachs are very difficult to count. As a result, a special technique had to be developed.
Because solid structures like fish bones and otoliths or chitinous fragments like the beaks of Cephalopoda or the crotchets
(jaws) of Nereis escape grinding by the stomach walls, these specimens can be used for counting. However, fish bones are often in an advanced state of digestion which hinders quantitative evaluation. We
have found on the other hand that the crystallins of fish eyes are not easily attacked by digestive juices and that in all probability they • are saved from pulverization by their spherical shape. Nevertheless, they are difficult to separate from the other debris in the stomach bolus. We therefore tried several sorting methods. Centrifugation of the food caused the muscular filaments to join into a mass which often included crystallins. Treating the stomach bolus debris (previously fixed in formol) with a potassium hydroxide (KOH) or pepsin solution yielded poor results because the ocular globes were attacked by this treatment more than the muscles. The best technique for the separation of crystallins and other useful structures like otoliths and chitinous crotchets etc., is the following:
a) - Sorting and washing. After separating out large objects like bones, flesh, etc. with tweezers, a stream of water was used to
O • 30-
FIGURE 8.- Two cod skeletons (Gadus callarias) and a squid (Illex illecebrosus) found in a male Beluga's stomach (#85) are laid out on the cloth and the rest of the food is placed in a cotton sack.
wash the remaining material through a wide mesh sieve (8 to an inch). The pieces missed during manual sorting are caught by the sieve and can be discarded. Fine debris and small fragments (crystallins,
crotchets, etc.) pass through and are caught below by a very fine mesh (64 to an inch.).
Afterwards, the sieved debris is washed in a tall, narrow container, such as a 500 cc graduated cylinder with a stopper equipped with two glass circulation tubes. The water enters one of these tubes and falls to the bottom causing an agitation that washes the muscle
tissue and other light particles to the top of the cylinder where they are drawn off through the shorter tube. Heavier particles like sand, crystallins and chitinous crotchets, etc. stay at the bottom of the cylinder. The water current can be adjusted so that • importantcomponents (crystallins, etc.) are not forced out at the same time as the muscle tissues. - 31 -
FIGURE 9.- The food found in the Beluga's stomach is mixed with a great number of parasitic worms (Anisakis simplex).
41F O - 32-
•
FIGURE 10.- The normal condition of the food taken from the stomach of Beluga: bits of fish, particles of crustaceans, parasitic worms, sand and other debris. Shown at 1/2 normal size.
• - 33 - • TABLE IX.- List of certain groups of invertebrates taken from the stomachs of Beluga caught in 1938 and 1939 in the St. Lawrence river.
Presence of species in
Species No. of Beluga Stomachs Nos.
Cephalopods Bathypolypus obesus (Verrill) ...... 21 see Appendix Illex illecebrosus (Le Sueur) ...... 35 11 it
Gastropods Buccinum undatum (Linnaens) ...... 10 3,52,58,61,69 85,108a,111, 121,133
Littorina sp? ...... 1 67
Lamellibranchia Crenella sp? ...... 2 65, 108a Cystodaria siligua Spengler...... 3 70,101,111 Macoma baltica Linnaeus ...... 1 108 Mesodesma arctata Conrad ...... 8 61,62,63,65, 99,133,135, 145 Mesodesma deaurata Turton ...... 6 47a,52,67,71, 126,127 Mesodesma sp? ...... 1 1 Mya sp? ...... 1 74 l'oldia limatula Say ...... 2 12,94
Polychaetes Cistenides gouldii Verrill ...... 21 49,55,58,60, 61, 62,65,67,69, 70,71,74,98, 101 121,127,132, 303,308,310, Nereis virens Sars ...... 64 see Appendix
0 - 34 -
The small amount of muscle that may remain with the crystallins does not affect the counting. Up to 400 cc of debris may be put in the cylinder for sorting.
If the food sample contains a lot of sand, the separation of crystallins and buccal crotchets by water becomes difficult because all these elements are of similar density. In this case, an
additional step should be added between the washing and counting, as follows:
h) Decanting crystallins and separating chitinous crotchets. The
water and the mixture of sand and crystallin obtained in the • graduated cylinder are poured into a small circular receptacle such as a crystallizer 10 centimetres in diameter (200 cc). After agitation, the crystallins rise to the surface of the sand and they can be quickly poured off without taking along the sand. This step is repeated until there are no crystallins left in the
crystallizer.
When a sample contains a number of Nereis crotchets mixed with
sand, it is placed under the tap on a 16-mesh sieve, and the
stream of water then washes out the fine sand leaving the crotchets.
c) Counting . After the washing process, the counting of -35 -
crystallins or Nereis crotchets begins. The contents of the
crystallizer or cylinder are poured into a glass basin. To facilitate the removal of crystallins, they are dispersed in the bottom of the basin in a little water. They then are separated one by one with tweezers and placed in a cardboard box in small groups of 10. The buccal crotchets are counted in the same way.
Depending on whether dark-coloured crotchets or light-coloured crystallins are being separated, the glass basin is placed on a light or dark surface to distinguish them more easily. We
found that the crystallins were easier to count when damp because • this prevented them from sticking to other debris. The Nereis crotchets, however, were easier to count dry.
Unfortunately, if there are a lot of crystallins in the food
sample, the actual counting takes a great deal of time. Within
certain limits, the diameter of the crystallins varies according to the size of the fish, even within the same species. In addition, the crystallins are often damaged by digestion and by preservation in formol. For this reason, the outer layer of the crystallins is often detached and their volume thus reduced.
Because of dimensional variations, the number of crystallins cannot be determined by either weight or volume. • The number of fish is calculated by dividing the number of - 36 -
O crystallins by 2. Otoliths are divided by 6 because fish have three
on each side of the head. The 6 otoliths of an individual are not all
identical: they are composed of 3 different sized pairs (sagitta, asteriscus and lapillus) matched between the left and right sides of
the fish. Often, the smallest otoliths (lapillus and sometimes asteriscus) are lost during handling, thus making division by 6 an
inaccurate means of counting the fish (1).
In the case of the clam worm (Nereis), squid and octopus, the number of individuals may be evaluated by dividing the number of worm
crotchets or Cephalopod beaks by 2. However, this method is not exact • because the left part of the Nereis jaw is different from the right, and the superior mandible of Cephalopods is quite distinct from the inferior mandible (2).
(1)However accurate the method employed, the determined number of specimens does not always indicate fish eaten by the Beluga in a single meal. On the contrary, it is quite likely that the different structures like fish crystallins and otoliths, chitinous parts of invertebrates, etc. which are not easily destroyed by digestion, may represent the accumulated remnants of several meals one or more days apart. (2)In figure 35 and throughout this publication, the terms superior mandible and inferior mandible are used for Cephalopods. The adjectives superior and inferior are used in a figurative sense. Actually, the mouth and tentacles are not found on the front of Cephalopods, but rather on their ventral side. Thus superior mandible should be posterior mandible and inferior mandible should • be anterior mandible. • - 37 -
FIGURE 11. The male (above) and female caplin (Mallotus villosus), shown at 4/5 of their actual size (Vladykov, 1941).
0 - 38 -
Nereis crotchets from one side may well be more numerous than those from the other side, or the superior mandibles of Cephalopods could be
more numerous than the inferior ones. Nevertheless, for all practical purposes, simple division by 2 is sufficient.
Species Identification
The food taken from the stomach of the Beluga is generally in an advanced state of digestion except when the prey is found in the gullet of the animal.
e Bivalve mollusks or Lamellibranchia can be identified by their shell, and Gastropods by their shell or operculum (1). The chitinous beak of Cephalopods, which is virtually untouched by digestion, can be used to identify this group. The beak of squid (Illex illebrosus), particularly the superior mandible, is more pointed than that of octopus (Bathypolypus obesus). In addition, in the former species, it is a yellowish or light brown colour, whereas the octopus beak is very dark, almost black. Other characteristics are shown in Figure 35.
(1) The chitinous teeth of the buccal rasp or radula of Gastropods are often found in Beluga stomachs. Although these radular teeth can be used in the identification of species, their number is too great to be advantageous in the enumeration of individuals. Similarly, the radular teeth of Cephalopods are not of no value to • this study. - 39-
TABLE X. Average number per stomach of individuals of the principal species, per stomach, removed from Beluga caught in 1938 on Manicouagan Bank
BELUGA Males Females Calve IMPORTANT INDIVIDUALS INDIVIDUALS INDIV DUALS FOOD COUNTED BY COUNTED BY COUNTE D BY SPECIES BONES CRYSTALLINS BONES CRYSTALLINS BONES CRYSTALLINS OR OR OTOLITHS OR OR OTOLITHS OR OR OTOLITHS BEAKS BEAKS BEAKS JUNE
Caplin 130(7) 263(4) No food in the 70(4) 722(4) Launce 14(1) 112(1) stomach •■•••■ Cod 4 (2)
1.11.• Nereis 1(1 ) Squid 7(1) 2(1) •Nie JULY
Caplin 117(7) 330(3) 112(5) 84( 2 ) 111(4) 601(2) • 3(2) 6(1) Launce 5(3) 112(2) 5(4) 77(3) Cod 2(5) 2(5) 1(2) 1(1) Nereis 8(5) 10(4) ••• 4(2) Squid 7(2) ,■• •■■• %M. AUGUST
Caplin 1(3) 47(3) 17(3) 159(1) ■01 Launce 3(7) 82(6) 12(10) 19(3) 230(2) Cod 6(13) 7(13) 1(6) 1( 7) 1(1) •■■■ Nereis 5(10) 318(8) 29(3) Squid 21(9) 16(8) 3(3) ■■•• SEPTEMBER
Caplin .- 1(1) 8(1) Launce 173(5) 78(3) 112(10) 282(9) 47(6) 160(5) Cod 1(1) 2(3) 2(1) Nereis 4(1) 261(10) •MI 32(5) Squid 2(2) 25(6) ■■■•■ 5(2) ■11
Note: The figures in brackets indicate the number of stomachs that contained individuals of the respective species. "Cod" includes traces belonging to the two species G. callarias and • G. oqac. • -40-
!..+^f 'k=i ^-•#a^ .ir^iŸt^•^^L^»+i:M^W^# . do .#aily•!dy ,.. ^ #s#•^• :.. .r;. , . . fN rv^a^M/r+#
it .
I^KM[ 2 3 4 S ANADIIIN LAMORATORY SUPPLI[S. LIMIT[O _ .
FIGURE 12. These 4,823 crystallins corresponding to at least 2,412 caplin (Mallotus villosus), were found in the stomach of a young Beluga male 10 feet, 4 inches long (#10).
0 - 41 - The crystallins of the eyes of Cephalopods are spherical, ressembling those of fish but they are divided into two parts,
anterior and posterior, by a circular groove at the point where the iris is attached (1). A crystallin taken from a Beluga stomach looks like a pearl. Digestion and formol cause deformation of the crystallins of these mollusks (Figures 31 and 32).
Fish crystallins are also more or less spherical but do not have a circular groove. The absence of the groove easily distinguishes them from Cephalopods. Figures 31 and 32 illustrate the typical shapes of crystallins of these two groups.
• The buccal crotchets of clam worms or "bloodsuckers" (Nereis) are often found in the food of the Beluga. These chitinous structures which act as mandibles have a very typical shape (2) that can be used to distinguish this worm (Figures 34 and 35) from other components of
the stomach bolus of the Beluga.
(1)Also, it has been noted that in the fur seal, the crystallins and chitinous beaks of Cephalopods are not digested. For this reason, these structures are very important in the analysis of the stomach contents of the fur seal (Shultz & Rafn, 1936). (2)Dr. Olga Hartman of the U.S. National Museum in Washington, informed us that the Nereis crotchets cannot be used to distinguish the species of this genus. • • - 42 - Identification of fish is more difficult: the species are
numerous and the bones are easily attacked by digestion. Larger species like the common cod (Gadus callarias) can be recognized by their cranial bones (e.g. vomer and premaxilla (1) and by their
otoliths and crystallins (Figures 15 and 16) which are quite large and have characteristic shapes. However, distinguishing between fragments
of common cod and Greenland cod (Gadus ogac) taken from a Beluga stomach is not always easy. In some cases, the bone and crystallin
remains of cod could easily be from both G. ogac and G. callarias. Tables X to XVIII and XXIV to XXXV, this possibility When examining
should be kept in mind. Similarly, tomcod or Microqadus tomcod is • often found together with Arctic cod (2) particularly in samples taken at Rivière-Ouelle.
In particular, we occasionally found the Copepod parasite (Lernea branchialis) of the common cod, although there were no fragments of
the latter in evidence. In the St. Lawrence region and probably in all of eastern Canada, Lernia
(1) Information on the cranial bones of cod can be found in an important study by Gregory (1935, pp.379-380). (2)When we began studying Beluga, only two species of cod were known in the St. Lawrence River: the common cod (G. callarias) and tomcod (M. tomcod). A few years later (Vladykow, 1945), we found two additional species: the Greenland cod (G. ogac) and the Arctic cod (Boreogadus saida). Although these species can easily be distinguished from each other when they are in a good state of preservation, fragments taken from Beluga stomachs cannot always be identified. O - 43 -
TABLE XI.- Average number, per stomach, of the principal species eaten by Beluga (male, female and young) in 1939 at Les Escoumains.
INDIVIDUALS COUNTED BY IMPORTANT FOOD SPECIES BONES OR BEAKS CRYSTALLINS OR OTOLITHS
JUNE Caplin 99(7) 435(6) Launce - Cod - 1( 5) Salmon 1(1) Nereis 5(5) Squid 36(4) JULY Caplin 49(8) 163(8) Launce 2(3) 218(3) Cod _ 1(4) • Salmon _ Nereis 4(7) Squid 54(6) AUGUST Caplin 5(1) Launce 1(1) Cod _ Salmon
Nereis 3 (1 ) Squid 3(1) NOTE: Figures in brackets indicate the number of stomachs containing individuals of the given species. The term "cod" includes remnants belonging to two species: G. callarias and G. ogac.
• - 44 -
branchialis only attacks common cod (1). For this reason, the fragments of these parasites found in the Beluga's stomach were sufficient proof that it had eaten cod.
Sometimes, the fish taken from the Beluga's stomach could be identified by the eye crystallins because the crystallin size varies
from one species to another: they are very large in haddock and cod; small in caplin and launce (Figures 12 and 16). Between the crystallins of the latter two species, size and colour differences can also be noted. Those of launce are whitish and very small (less than one millimeter in diameter) while those of caplin are a fairly dark • grey and the diameter is a little larger (about li mm). This contrast is accentuated by placing several crystallins of each species in separate tubes making identification easier.
The tail skeleton is the most useful part taken from the Beluga's
(1) According to Scott & Scott (1913, p. 143), in the waters around the British Isles, the adult females (the males are not parasitic of Lernea branchialis not only live on common cod but on haddock and whiting (Gadus merlangus) as well. Whiting does not exist in Canada, and distribution of haddock in the province of Québec is limited to the Gulf of St. Lawrence. Wilson's observations (1932, p. 486) in the Woods Hole region support our observations, i.e., L. branchialis of North America only attacks the common cod (Gadus callarias). Nevertheless, the presence of Lernea branchialis in species other than the common cod, species such as G. ogac common • to the North Coast), has not been sufficiently studied. - 45 -
stomach for the identification of small fish like caplin, smelt,
launce, etc, (1).
(1) Documentary information on this subject is provided, for example, by the following authors: Barrington (1937), Hollister (1936), and Thompson & Van Cleve (1936, pp.83-88). 0 _46 _ •
0
FIGURE 13. Two fish commonly found in the St. Lawrence: the herring ( Clupea harengus) and sand launce (Ammodytes americanus). Around 3/4 ofnatural size. The herring ( above) is represented by a young individual, commonly known as a "sardine".
0 - 47 -
ALIMENTARY REGIMEN OF THE BELUGA
There are many authors who provide some information on the alimentary regimen of the Beluga, for example, Arsenyev (1939), Beddard (1900), Birula (1934), Freund (1932), Heptner (1930), Kellogg (1940), Lacépède (1844), Struthers (1896), Sutton & Hamilton (1932), Tschirkowa & Folitarek (1930). As can be expected, the diet of this Cetacean varies with the region. For this reason, documentary data collected elsewhere, cannot be directly applied to the conditions of the St. Lawrence River.
• GENERAL CONSIDERATIONS
There is no divergence of opinion among authors on the general composition of the food of the Beluga, which primarily consists of fish, crustaceans and mollusks. In certain locations, the Beluga
prefers a certain type of fish or crustacean which is probably in abundance, whereas elsewhere it feeds on other fish, crustaceans, etc.
Published information on the maximum size of the fish and other
animals eaten by Beluga is imprecise. Nevertheless, Arsenyev (1939,
p.34), speaking of the diet of the Beluga of the North Pacific, which are larger than those of the St. Lawrence, mentions that the largest • prey that he found was a salmon (Oncorhynchus keta) of about -48 -
TABLE XII. - Number of stomachs, with food, of young Beluga taken in 1938 on the Manicouagan Bank
TYPE OF FOOD JUNE JULY AUGUST SEPTEMBER GRAND TOTAL NUMBER OF STOMACHS Caplin 4 5 - 1 10 Launce 2 3 6 11 Sculpin 1 1 2 - 4 Tomcod - - - - Flounder Cod (1) 1 1 1 3 Salmon - - - - Other fish 1 - 1 - 2 Squid 1 - 3 2 6 Octopus - 1 1 2 Nereis 1 2 3 5 11 Polycheta - 3 - 3 Decapoda 2 2 2 4 10 Amphipoda - 1 1 - 2 Other crustaceans - 1 - - 1 Lamellibranchia - 2 2 2 6 Gastropoda 1 1 1 3 • Other animais 3 2 - - 5 Plants 2 3 2 6 13 Total number of stomachs 4 6 3 6 19
(1) In this and in Tables XIII to XVIII, "cod" includes traces of both G. callarias and G. ogac.
e • - 49 -
•
Figure 14. Young individuals of three species of Gadidae: a) squirrel hake (Urophycis chuss); b) common cod (Gadus callarias ; c) tommy cod or Atlantic tomcod (Microgadus tomcod). About 3/4 natural size.
0
- 50-
TABLE XIII Number of stomachs, with food, of Beluga females taken in 1938 on the Manicouagan Bank
TYPE OF FOOD JUNE JULY AUGUST SEPTEMBER GRAND TOTAL NUMBER OF STOMACHS Caplin 5 3 1 9 Launce 4 10 10 24 Sculpin 1 5 3 9 Tomcod 1 2 4 7 Flounder 2 3 5 Cod (1) 2 7 3 12 Salmon - - - Other fish No - 2 1 3 Squid stomachs 8 6 14 Octopus with - 4 2 6 Nereis food 4 8 10 22 Polycheta 1 6 4 11 Decapoda 6 9 9 24 Amphipoda 2 2 5 9 Other crustaceans - - - Lamellibranchia 1 7 6 14 Gastropoda 1 2 3 Other animais 3 4 1 8 Plants 6 8 8 22 Total number of stomachs 8 11 10 29
• - 51 -
5 pounds (1). According to the same author, the Beluga's stomach
cannot hold more than 50 pounds of food.
The largest fish in our own collected data was a common cod about
30 inches long which probably weighed about 10 pounds (2). It was
taken from a 13-foot 8-inch male Beluga (#85). In another case, a
14-foot male Beluga (#86) pursued by a hunter in a power-boat, vomited
a 24-inch sturgeon of about 2 pounds (3).
These examples demonstrate quite clearly that Beluga, including
large ones, are incapable of swallowing large-sized fish. Further to
this, conservation officer Paul Bélanger reported an interesting case
to us: in June 1937, a dead Beluga found near Les Escoumains, had a
cod about, 40 inches long and weighing almost 23 pounds, obstructing
its gullet. A century ago, Lacépède (1844, p.84)
(1) According to certain Russian authors, the Beluga of the Sea of Okhotsk and North Pacific belong to a particular species (D. dorofeevi) which is different from that of eastern Canada. Remarks on this subject are in our previous publication (Vladykov, 1944, p.48). (2) Additional information on the size of cod found in stomachs of Beluga, estimated by the length of their premaxillary bones, is given on page 116 of this publication. (3) This sturgeon was caught afterwards with a dipnet and eaten by the hunter because the fish was not yet touched by digestion.
0 - 52 -
speaking about the alimentation of Beluga, wrote that this Cetacean
feeds on several species of Gadidae, particularly haddock and cod: The Beluga seeks them constantly, pursues them with eagerness, and swallows them greedily. Since its gullet is very narrow, it is in danger of being suffocated by
too much or too great a prey.
We observed that it took 5 gallons of water to fill the esophageal
region of the stomach of an adult Beluga 12i- feet long; and that the maximum amount of food that a White Whale can swallow in a single meal • weighs little more than 50 pounds. In one case, the stomach contents at the time of removal from the Beluga (#10) weighed only 9 ounces, but we found bones belonging to at least 210 caplin, and 4,823 crystallins of the same species (Fig. 12). These crystallins represent at least 2,412 caplin, for which
the estimated weight would be 138 pounds and the volume 92 gallons. There is little doubt that this enormous quantity of food does not represent a single "feast" but is the result of an accumulation of crystallins of fish ingested over several meals.
In our case, we were not able to remove a large amount of food from Beluga because the stomach bolus was always in an advanced state of digestion and, in addition, the Beluga often vomited part of it. • The largest amount found in a single stomach ,75,. lee 4001e ,'41111110 ele datie die ' • e( FIGURE 15. Otoliths of two species of Gadidae: a) common cod (Gadus callarias); b) tomcod (Migrogadus tomcod) O - 54 - weighed just under 19 pounds: this was found in a male (#85) 12 feet 8 inches long, killed August 19, 1938. Its stomach bolus, weighing almost 12 pounds and in an advanced state of digestion, contained mainly cod bones and some squid. Besides food, it also contained a granite stone weighing 6 lbs. 14 oz. (Fig. 37). The number of aquatic species taken from the stomachs of Beluga in the St. Lawrence River is approximately 50 (Tables VIII and IX). Heptner (1930, p. 54) mentions that Beluga of northern Russian waters feed on at least a hundred different species of fish. • In addition to various animals, we have often found the stomachs of Beluga to contain fragments of aquatic plants and pieces of bark or leaves from terrestrial vegetation. Among the interesting things observed, the red paper in which oranges are usually wrapped is noteworthy. We removed such papers from two stomachs. Several stomachs also contained sand and pebbles. As mentioned previously, the Beluga of the St. Lawrence River, when wounded or pursued by power-boats for example, often vomit the contents of their stomachs. Heptner (1930, p.40) gives this as the reason for the frequent absence of food in the stomachs of Belugas killed in the summer in the north of Russia. O - 55 - Feeding mode According to Heptner (1930, p.20), Beluga in northern Russia often gorge themselves on small jellyfish and ctenophores (1) which they seize near the surface of the water. On the other hand, Beddard (1900, p.245), on finding sand in Beluga stomachs, assumed that they used sand as a ballast to facilitate feeding at great depths in the ocean. We do not share the latter opinion: to begin with, the Beluga, as we explained in our last publication (Vladykov, 1944), is an animal which frequents almost exclusively the coastal area and rarely ventures out to sea. In addition, on several occasions, we • observed that Beluga when "grazing" would dive for a very short duration, of only a few seconds (2). The composition of the foods also indicated that it feeds in shallower waters (Table VIII). As a matter of fact, we have never removed from Beluga stomachs fish like Lycoda and Liparidae (Vladykov & Tremblay, 1935 and 1936), which are found in the depths of the St. Lawrence. (1)At Les Escoumains, hunters call ctenophores "soleils-de-mer" (sunfish). (2)However, hunters maintain otherwise. J.F. Moreau of Les Escoumains, while hunting in a sailing canoe, struck a Beluga with a harpoon attached to a 35 fathom line and buoy. This Beluga descended straight to the bottom so quickly that not only the line but also the buoy dissapeared from the surface of the water. When the animal resurfaced, its hide was covered with a great number of sea-urchin spines thus indicating that it had been rolling on the bottom. However, it must be remembered that a seriously wounded animal is completely different in behaviour from a normal animal. O - 56 - • FIGURE 16. Two views of a cod (Gadus callarias) crystallin taken from the stomach bolus of a Beluga and fixed in formol. Enlarged 6 times. • St. Lawrence hunters agree that the Beluga, in order to find food in summer, forages along the bottom, thus swallowing a lot of sand. It prefers sandy banks in shallow waters, where it often feeds in a vertical position with its tail visible out of water. Analyses of stomach contents frequently revealed large quantities of sand, as much as 5 lbs. (Fig. 36.). This sand is undoubtedly swallowed when Beluga graze on bottoms rich in clam worms (Nereis). It is quite probable that the White Whale catches sand launce at the same time. However, it seems that the Beluga does not take launce directly from the sand but at a certain distance from the bottom. In fact, during the period of abundance of Nereis which coincides with that of sand launce, there is a very pronounced correlation between O - 57 - the quantity of sand in Beluga stomachs and the number of Nereis swallowed. For example: BELUGA LAUNCE NEREIS SAND Specimen # No. of crystallins Number of jaws Weight (grams) . 140 1,175 27 15 135 1,012 1 5 99 164 13 5 108 440 20 25 62 8 43 40 127 338 1,366 1,050 121 208 1,255 1,100 111 250 2,469 2,140 101 455 2,732 1,650 70 220 2,222 2,315 • Other than sand, one often finds stones varying from 1/4 to 6 inches in diameter in the Beluga's stomach. Undoubtedly, it collects them on the bottom while searching for clam worms or other invertebrates. In the beginning of summer, at floodtide, Beluga come very close to shore to gorge on their favorite food, caplin, which are spawning then in large schools. Later, they feed on another gregarious species, launce, in the same shallow waters. Since the White Whale is not a good swimmer, it cannot easily catch large, fast fish like salmon. On the other hand, small, slow fish like flounder and • sculpin, found at the bottom of shallow waters, are a common food. - 58 - COMPOSITION OF FOOD Among the works published on the Beluga diet, that of Arsenyev (1939) is the most important. He had at his disposal 102 stomachs containing food other than milk. His studies were on the Beluga of the northern Pacific region and the Bering and Okhotsk seas. Arsenyev noted the presence of 11 species of fish and 4 species of crustaceans. The following are in order of importance: Keta salmon (Oncorhynchus keta) in 54 stomachs Wachna cod (Eleginus navaga) in 32 stomachs Shrimp (Crangon septemspinosa) in 29 stomachs As we shall see, the composition of the Beluga diet in the St. Lawrence River is quite different from that of North Pacific Regions. To facilitate detailed comparison of stomach contents between Beluga individuals, we have used two main criteria: the frequency of a given species, that is, the number of stomachs containing individuals of the species; and the quantity of a given species, i.e. the degree to which the stomach is filled by the number of individuals of the species or by their total weight (or volume). 0 It should be taken into consideration that our samples of Beluga -59 - O TABLE XIV.- Number of stomachs, with food, of male Beluga taken in 1938 on the Manicouagan Bank Type of June July August September food TOTAL NUMBER OF STOMACHS Caplin 9 7 3 - 19 Launce 1 3 9 5 18 Sculpin 3 2 10 - 15 Tomcod 1 4 - - 5 Flounder - - 3 1 4 Cod 2 5 13 1 21 Salmon - - - - - Other fish - 1 10 - 11 Squid 1 3 9 2 15 Octopus - 2 2 - 4 Nereis - 5 10 1 16 Polycheta - - 5 - 5 Decapoda 2 4 15 2 23 Amphipoda - 4 6 - 10 Other crustaceans - - 1 - 1 • Lamellibranchia 2 1 8 3 14 Gastropoda 2 1 7 1 11 Other animals - 1 8 - 9 Plant 3 5 11 2 21 Total number of 9 10 16 5 40 stomachs • -60- TABLE XV. - Number of stomachs, with food, of Beluga ( male, female and young) taken in 1938 on the Manicouagan Bank TYPE OF FOOD I JUNE JULY AUGUST SEPTEMBER GRAND TOTAL NUMBER & °b Caplin 13 100.0 17 71.0 6 20.0 2 9.5 38 43.2 Launce 1 7.7 9 37.5 22 73.5 21 100.0 53 60.2 Sculpin 4 30.8 4 16.7 17 56.6 3 14.3 28 31.8 Tomcod 1 7.7 5 20.8 2 6.7 4 19.0 12 13.6 Flounder - - - - 6 20.0 6 28.6 12 13.6 Cod 2 15.4 8 33.4 21 70.0 5 23.8 36 41.0 Salmon ------Other fish 1 7.7 1 4.2 13 43.4 1 4.8 16 18.2 Squid 2 15.4 3 12.5 20 66.6 10 48.0 35 39.8 Octopus - - 2 8.4 7 23.3 3 14.3 12 13.6 Nereis 1 7.7 11 45.8 21 70.0 16 76.0 49 55.7 Polycheta ,- - 1 4.2 14 46.6 4 19.0 19 21.6 Decapoda 4 30.8 12 50.0 26 87.0 15 71.5 57 64.7 Amphipoda - - 7 29.2 9 30.0 5 23.8 21 23.9 Other crustaceans - 1 4.2 1 3.3 - - 2 2.3 Lamellibranchia 2 15.4 4 16.7 17 56.6 11 52.5 34 38.6 • Gastropoda 2 15.4 2 8.4 9 30.0 4 19.0 17 19.3 Other animals 3 23.0 6 25.0 12 40.0 1 4.8 22 25.0 Plants 5 38.4 14 58.5 21 70.0 16 76.0 56 63.6 Total number of stomachs 13 100.0 24 100.0 30 100.0 21 100.0 88 100.0 stomach boluses represent only the minimum quantities: the food was in an advanced state of decomposition and very often the volume had been reduced by vomiting. For these reasons, in order to determine the role of a species, from the viewpoint of its importance as food for the Beluga, its frequency and quantity should be considered simultaneously. Indeed, frequency alone or quantity aloneis not enough data for accurately determining the importance of the species: the first criterion tells nothing of the size of the animal or the • amount consumed; the second does not give the number of stomachs in - 61 - I which the particular species is found. For example, the frequency of the caplin and cod can be the same but, because of the large difference in size, the Beluga would have to swallow much more caplin than cod in order to ingest an equal weight (or volume) of food. If the weight of one caplin is one ounce and one cod weighs five pounds, then, in order to have a comparable quantity of the two species, the Beluga must eat BO caplin for each cod. However, if two species of a similar size, like caplin and launce, are eaten in equal amounts, the species identified in the greatest number of stomachs is the mostimportant one. • The analysis of the stomachs of Belugas taken in the St. Lawrence River reveals the importance of the following four types of animals: fish, marine worms (Polycheta), mollusks (Cephalopoda) and crustaceans. Fish Of the 107 stomachs with food which were examined in the laboratory, all contained fish. We found 22 different species, the frequency of which is given in Table VIII. Since in the following chapter we shall be discussing in detail the connections between Beluga and fish of economic importance, we shall discuss only non-commercial species or those of lesser O - 62 - TABLE XVI. - Number of stomachs, with food, of Belugas taken from June to September of 1938 on the Manicouagan Bank BELUGA : TYPE MALE FEMALE YOUNG GRAND TOTAL OF FOOD NUMBER & % Caplin 19 47.5 9 31.0 10 52.6 38 43.2 Launce 18 45.0 24 82.7 11 58.0 53 60.2 Sculpin 15 37.5 9 31.0 4 20.8 28 31.8 Tomcod 5 12.5 7 24.1 - - 12 13.6 Flounder 4 10.0 5 17.0 3 15.8 12 13.6 Cod 21 52.5 12 41.5 3 15.8 36 41.0 Salmon - - - - - - - - Other fish 11 27.5 3 10.2 2 10.4 16 18.2 Squid 15 37.5 14 48.2 6 31.2 35 39.8 Octopus 4 10.0 6 20.4 2 10.4 12 13.6 Nereis 16 40.0 22 75.8 11 58.0 49 55.7 Polycheta 5 12.5 11 38.0 3 15.8 19 21.6 Decapoda 23 57.5 24 82.7 10 52.6 57 64.8 Amphipoda 1 25.0 9 31.0 2 10.4 21 23.8 Other crustaceans 2.5 - - 1 5,2 2 2.3 Lamellibranchia 14 35.0 14 48.2 6 31.2 34 38.6 Gastropoda 11 27.5 3 10.3 3 15.8 17 19.3 • Other animals 9 22.5 8 27.6 5 26.3 22 25.0 Plants 21 52.5 22 75.8 13 68.5 56 63.6 Total number of stomachs 40 100.0 29 100.0 19 100.0 88 100.0 monetary value at this point. Caplin (Fig. 11). - The caplin is one of the most important fish in the diet of St. Lawrence River Beluga: we found them in 54 stomachs or 50.5% of our samples (Table XVIII). We have already noted that in the Arctic seas of Europe (Heptner, 1930, p.20; Freund, 1932, p.43), Beluga sustain themselves largely on this fish as well. The adult caplin is a small-sized fish 6 to 8 inches long and • weighing about one ounce. Figure 17. Two views of the bone (premaxillary) of the superior mandible of a cod (Gadus callarias). The size of the cod • can be estimated from the length of the premaxillary. Figure 18. Three adult females of the Copepod parasite (Lernea branchialis) of cod (Gadus): a) dorsal view of the parasite on the gills of a cod; h) parasite separated from the host with the head below and the spiral ovaries above; c) ventral view of the parasite on cod gills. O -64- The following data are for some individuals taken during spawning on May 30, 1938 at Manicouagan Point: SEX TOTAL BODY WEIGHT VOLUME LENGTH (1) LENGTH (1) (mm) (mm) (g) (cc) 137 128 15.5 14 156 146 23.0 21 156 147 24.0 22 ^ 157 146 26.5 25 173 162 34.0 32 Cr 180 167 33.0 32 Average 159.8 140.3 26.0 24.3 (6.3 (5.9 (0.9 (1.48 inches) inches) ounces) cu.in) 0 Tables X and XI give information on the average number (quantity) of caplin found per stomach in Beluga taken on the Manicouagan Bank and at Les Escoumains. It can be clearly seen that White Whales feed almost exclusively on this fish at the beginning of summer; however, during August, the amount of caplin diminishes considerably and, in September, we find it only rarely and in very small quantities in our samples. (1) The total length is measured from the end of the snout to the extremity of the tail (caudal fin); the body length is measured from the tip of the snout to the fork in the tail. 0 • -65 - In order to better appreciate the importance of caplin in the Beluga diet, we add the following data on the maximum quantities taken from individual stomachs: BELUG A NUMBER OF C APLIN EST IMATED Y SEX LENGTH DATE OF CAPTURE BONES CRYSTALLINS (in.) Young Beluga 10 100 24 .VI.38 210 2,412 24 92 7.VII.38 137 1,168 34 97 14.VII.38 133 60 Adult Beluga 25 135 7.VII.38 198 1,502 30 136 11.VII.38 168 195 35 c> 143 14.VII.38 190 147 305 123 28. VI.39 107 702 307 y 144 30. VI.39 316 966 311 Y 131 15.VII.39 114 77 9 dr 163 24. VI.38 296 900 26 0.71 161 7.VII.38 179 351 27 (9> 161 8.VII.38 384 10 We removed the largest number of caplin from the stomach of a young male Beluga (#10) 8 feet 4 inches long, taken June 24, 1938 on the Manicouagan Bank. Even though its stomach contents weighed only 8 ounces, we found 4,823 caplin crystallins corresponding to at least 2,412 fish (Fig. 12). Launce (Fig. 13) - The publications consulted do not mention this • fish in the diet of the Beluga. However, in the St. Lawrence region, - 66- the launce is certainly one of the most important food sources of the White Whale. We found it in 58 stomachs, i.e. 54,2 percent of our samples (Table XVIII). As an example of the size of launce regularly eaten by the White Whales of the St. Lawrence, let us consider the stomach contents of a female Beluga (#140) 11 feet 9.. -. inches long, taken on September 23, 1938 on the Manicouagan Bank: LAUNCE TAKEN FROM BELUGA #140 LENGTH OF BODY (1) WEIGHT (mm) (g) Females 140 7.6 160 10.9 165 14.3 180 17.1 Males 145 7.7 e 145 7.7 145 8.1 150 10.0 155 10.0 155 11.0 155 11.6 155 12.0 160 9.4 160 10.8 160 11.1 165 14.6 170 9.7 170 12.9 170 13.8 170 16.9 175 10.4 175 13.5 180 12.9 185 14.4 Average 162 (6.2 inches) 11.6 (0.4 ounces) (1) The body length is measured from the tip of the snout to the fork in the tail. O -67- Launce is much appreciated by young and old White Whales of both sexes. Table X indicates the average quantity of this fish found in the stomachs of Belugas on the Manicouagan Bank. Unlike caplin, launce are a secondary food source at the beginning of summer, and thus, we do not find many launce in the samples taken at that time of year at Les Escoumains for example, (Table XI). However, in August and particularly September, when the coastal waters have warmed up, launce are abundant on shallow, sandy bottoms, and the White Whale then feeds mainly on this fish. The following are some examples of the maximum numbers of launce 0 observed in the stomachs of Beluga: BELUG NUMBER OF L AUNCE COUNTED BY SEX LENGTH DATE OF CAPTURE BONES CRYSTALLINS (in.) Young Beluga 98 90 30.VIII.38 54 235 112 119 2. IX.38 101 165 146 1142 24. IX.38 105 334 Adult Beluga 135 142 11. IX.38 283 506 138 130 12. IX.38 149 122 140 1412 23. IX.38 323 588 145 t^ 125 24. IX.38 185 442 126 148 9. IX.38 478 - 136 176 11. IX.38 103 167 • 141 e 122 23. IX.38 244 81 O - 68 - The largest number of launce were found in the stomach of a male Beluga (#126) 12 feet 4 inches long, taken on the Manicouagan Bank: we counted the skeletal remains of 478 individuals. Sculpin (Fig. 19) We found two species: the first (Gymnocanthus tricuspis), comprised of individuals 6 to 8 inches long, was identified in only two stomachs; the other (Myoxocephalus groenlandicus), varying from 10 to 15 inches in length, was observed 33 times (Table VIII). As a point of interest, one individual of M. groenlandicus, 7 inches long and weighing about 3i, ounces, was removed intact from the gullet of a male Beluga (#14) 137 inches long. The photograph of this fish is at the bottom of Figure 19. Usually we observed only one sculpin per stomach bolus. The exceptions where we identified several individuals at a time were among the samples taken in 1938 on the Manicouagan Bank: BELUGA NUMBER OF M. Groenlandicus ESTIMATED Y # SEX LENGTH DATE OF CAPTURE BONES CRYSTALLINS (in.) 42 d 139 20. VII 4 - 67 e 160 3.VIII 5 - 69 cr 169 3.VIII 3 - 91 e 169 23.VIII - 5 92 e 130 23.VIII - 10 O - 69 - • FIGURE 19 - Dorsal and lateral views of two specimens of sculpin (Myoxocephalus groenlandicus). About -1 the actual size. In short, Beluga do not consider sculpin a great delicacy: they eat them in the summer in small quantities for lack of better fare. Tomcod, kingfish or tommy cod (Figures 14 and 15). We found this little 6 to 8 inch-long fish in 18 stomachs (Table VIII). Notably, only adult Beluga, females in particular, eat this fish. O - 70 - TABLE XVII. - Number of stomachs containing food other than milk. Beluga (male, female and young) taken in 1939 in the St. Lawrence River. TYPE OF FOOD JUNE JULY AUGUST NOVEMBER GRAND TOTAL NUMBER & % Caplin 7 100.0 8 100.0 1 50.0 - - 16 84.2 Launce - - 3 37.5 2 100.0 - - 5 26.5 Sculpin 3 42.9 1 12.5 1 50.0 2 100.0 7 37.1 Tomcod 3 42.9 1 12.5 - - 2 100.0 6 31.8 Flounder 1 14.3 - - - - - - 1 5.3 Cod 5 71.5 4 50.0 - - - - 9 47.5 Salmon 1 14.3 - - - - - - 1 5.3 Other fish 2 28.6 1 12.5 1 50.0 - - 4 21.2 Squid - - - - - - - - - - Octopus 3 42.9 6 75.0 - - - - 9 47.7 Nereis 5 71.5 7 87.5 1 50.0 2 100.0 15 79.0 Polycheta 1 14.3 2 25.0 - - - - 3 15.9 Decapoda 4 57.2 6 75.0 1 50.0 1 50.0 12 63.1 Amphipoda 4 57.2 8 100.0 2 100.0 2 100.0 16 84.2 • Other crustaceans 2 28.6 - - - - - - 2 10.6 Lamellibranchia 1 14.3 1 12.5 - - 1 50.0 3 15.9 Gastropoda 2 28.6 - - - - - - 2 10.6 Other animals 1 14.3 - - - - - - 1 5.3 Plants 5 71.5 6 75.0 1 50.0 - - 12 63.1 Total number of stomachs 7 100.0 8 100.0 2 100.0 2 100.0 19 100.0 O - 71 - TABLE XVIII.- Number of Beluga stomachs containing food other than milk Place Manicouagan Les Escoumains Rivière-Ouelle Grand Bank Total 1938 Season June - Sept. June - August November and 1939 Year 1938 & 1939 1939 1939 Type of food Number °6 Number °b Number % Number °S Caplin 38 42.8 16 100.0 - - 54 50.5 Launce 54 60.6 4 25.0 - - 58 54.2 Sculpin 28 31.5 5 31.0 2 100.0 35 32.7 Tomcod 12 13.6 4 25.0 2 100.0 18 16.8 Flounder 12 13.6 1 6.3 - - 13 12.0 Cod 36 40.5 9 56.0 - - 45 42.0 Salmon - - 1 6.3 - - 1 0.9 Other fish 16 18.0 4 25.0 - - 20 18.7 Squid 35 39.4 - - - - 35 32.7 Octopus 12 13.6 9 56.0 - - 21 19.6 Nereis 49 55.0 13 81.0 2 100.0 64 59.8 Polycheta 19 21.4 3 18.8 - - 22 20.6 Decapoda 57 64.0 11 69.0 1 50.0 69 64.5 Amphipoda 22 24.8 13 31.0 2 100.0 37 34.6 Other crusta eans 2 2.2 2 12.5 - - 4 3.7 Lamellibranchia 34 38.2 2 12.5 1 50.0 37 34.6 Gastropoda ^ 17 19.0 2 12.5 - - 19 17.8 Other animal 22 24.8 1 6.3 - - 23 21.4 Plants 56 63.0 12 75.0 - - 68 63.5 Number of stomachs 89 100.0 16 100.0 2 100.0 107 100.0 f - 72 - FIGURE 20 - Two species of flounder common in the St. Lawrence River: a) Liopsetta putnami; b) Pseudopleuronectes americanus 0 - 73 - In our samples, we usually came across only one individual per stomach. The exceptions are indicated in the table below: BELUGA NUMBER OF TOMCOD ESTIMATED BY # SEX LENGTH DATE OF CAPTURE BONES OTOLITHS (in.) 58 9... 132 1.VIII.38 - 3 99 q>_ 126 30.V111.38 10 2 140 cZ' 1411 23. IX.38 2 27 143 121 23. IX.38 1 5 145 125 24. IX.38 - 3 332 9. 140 7. X1.39 - 15 333 e 1291 3. XI.39 13 33 L • Belugas eat a little tomcod in the summer, and we found some at Rivibre-Ouelle in November. It is quite probable that in the samples from this location, tomcod remains were mixed with those of Arctic cod. Indeed, it was at Rivière-Ouelle in the autumn that we found Arctic cod in an eel trap (Vladykov, 1945). There is no tomcod (M. tomcod) in the European arctic seas but there is a related species, Eleginus navaga. The latter fish and Arctic cod (Boreoqadus saida) are often included in the Beluga diet (Birula, 1934, p.14; Tschirkowa & Folitarek, 1930, p.113). Flounder (Figure 30) - We found three species in the stomachs of Beluga: O - 74 - O Glyptocephalus cynoglossus 1 time, at Les Escoumains, 1939; Liopsetta putnami 5 times, on the Manicouagan Bank, 1938; Pseudopleuronectes americanus 9 times, on the Manicouagan Bank, 1938. In 1938, we found flounder other than Gluptocephalus cynoglossus in only 12 stomachs. The number of these fish in the stomach bolus varied from one to four. The details are: • BELUGA . NUMBER OF SPECIMENS # SEX LENGTH DATE OF CAPTURE L. putnami P. americanus (in.) Young Beluga 74 103 - 9.VIII 1 112 119 2. IX 4 3 113 2. IX 1 Adult Beluga 71 Q 122 7.VIII - 1 99 1, 126 30.VIII - 1 111 151 2. IX 1 1 127 137 9. IX 1 - 132 Q 131 10. IX 1 - 85 cr 164 19.VIII - 1 94 e 176 27.VIII - 1 108a & ? ?.VIII - 1 139 cle 129 16. IX - 1 Based on the skeletons taken from these stomachs, we can conclude -75- that the Beluga eats only young flounder varying from 7 to 9 inches in length. In summer, these young individuals are found mainly in shallow water. A single specimen (8 inches) of deepwater flounder (Glyptocephalus cynoglossus), which inhabits water at least 60 feet deep (1), was removed from a female Beluga (006) 11 feet 4 inches long, taken at Les Escoumains on June 30, 1939. Due to the strong, cold currents of the Saguenay, several animals like shrimp, fish, etc., which are usually found in the depths, can often be found near the surface in this region. This is probably the case with our specimen of G. • cynoglossus. In the White and Barentz seas, Belugas eat other species of flounder like Pleuronectes platessa and P. glacialis (Heptner, 1930, p.55; Birula, 1934, p.15). (1) According to Bigelow & Welsh (1925, p. 513), in the Gulf of Maine, I this flounder (G. cynoglossus) is found most often at depths between 25 and 100 fathoms. • FIGURE 21. Two views of a young sturgeon (Acipenser oxyrhynchus). About natural size. -77- Sturgeon (Fig 21) - Three young specimens were taken from the stomachs of Beluga. One of these fish, 24 inches long and weighing about 2 pounds, was vomited by a male Beluga (#86) taken on the Manicouagan Bank. The other two individuals were even smaller judging by some osseous plates found in the stomach bolus. The latter fish were taken from a male (#304) and a female (016) Beluga caught at Les Escoumains. Because of its large size, the sturgeon does not seem to be a common food of the Beluga. Haddock - Bone fragments from three individuals (Table VIII) of this species, which is very common in Nova Scotian and eastern and western Atlantic waters, were taken from Beluga stomachs. Identification was possible because of the widened part (conoidal portion) of the clavicle or cleithrum, a bone of the pectoral girdle. The widening of the cleithrum is one of the most distinctive characteristics of the Haddock skeleton (1). Finding these bones in the stomachs of Beluga taken in 1938 on the Manicouagan Bank is quite interesting because, in the Province of Quebec, the distribution of haddock is limited to the Gulf of St. Lawrence. Without any doubt, our Beluga did not swallow the haddock whole but simply picked up the bones from the sea bottom. (1) A drawing of the pectoral girdle of haddock can be found in Figure 24 of an important work by Brooks ( 1885) on the osteology of.this • fish. -78 - O Sailors commonly throw galley leftovers overboad. In the case of fish, the bones of the pectoral girdle are thrown overboard with the head, fins and entrails, etc. This is the probable explanation for the presence of haddock bones in the stomachs of Beluga from the Manicouagan Bank. However, we should remember that, in Europe, Beluga often eat haddock (Heptner, 1930, p.55), a fish much smaller than the common cod. Smelt (Fig. 22) - In summer, along the St. Lawrence, this fish keeps to salty waters close to shallow banks often covered with weeds. Thus, the Beluga rarely have a chance to catch them. Only in • the autumn and early spring, when the water temperature is low, do smelt congregate in large schools, thus becoming easy prey for Beluga. Unfortunately, we do not have a stomach taken during these seasons, and this is why smelt are rare in our samples. In fact, we only found them once, in a female Beluga (#99) 10; feet long, taken on the Manicouagan Bank on August 30, 1938. From its stomach, we removed at least 9 smelt, counted by their skeletal remains, and 264 crystallins evidently belonging to the same species. Many years ago, Abbé Casgrain (1873, p.9) observed at Rivière- Ouelle that Beluga come close to land in spring in order to gorge on small fish. He said that it was customary to set the weirs from April 8 to 25. - 79 - ■ FIGURE 22 - Male (above) and female smelt (Osmerus mordax). Actual size s - 80 - "about the time when the caplin and smelt arrive to spawn along the shore. (1) Since these little fish are one of the primary and most abundant spring food sources of the White Whale, this is when it approaches land and to pursue them. Spawning takes place with the rising tide, which is also dinner time for the White Whale." Figure 23 - An eel (Anguilla bostoniensis) with white vertical marks probably caused by the teeth of a Beluga. In the autumn, smelt congregate in large numbers in the estuaries of several rivers along the St. Lawrence in order to winter close to their spawning grounds. During this season and in winter as well, they become very hungry and snap at baited hooks. (1) We can confirm Abbé Casgrain's information on the smelt spawning season. Indeed, in our sample taken April 23, 1945, in an eel trap belonging to Emile Lizotte of Rivière-Ouelle, we noted that several smelt had already spawned. - 81 - For example, in the city of Québec, it is typical from the end of September to the middle of November to see anglers perched all along the quays, fishing for smelt. This is the season when smelt, like the Beluga, go up the River.(1) We have no samples of Beluga food from the Québec area in autumn but it is quite probable that they often eat smelt at this time of year. According to Arsenyev (1939, p.29), the Beluga of the North Pacific also eat a limited amount of smelt (0. dentex). FIGURE 24 - Egg capsules of three species of skate (according to Vladykov, 1936): a) and b) Raja senta; c) R. radiata; d) R. scabrata (1) The relationship between smelt and Beluga, as noted by fishing buffs, can be illustrated by the observations of Jacques Després of the Department of Fisheries and Game: "at about 3 p.m. October 20th, 1945 at ebbtide, I saw a creamy white adult Beluga surface about 50 yards from the quay near the Customs Building in Québec. Curiously, the smelt, which should really have been biting at that • tide, did not take the bait, and angles went almost empty-handed that afternoon." -82- Other fish - Apart from the fish already mentioned, which for the most part constitute the regular diet of the St. Lawrence Beluga, we ,occasionally removed eight other types of fish (Table VIII). These do not, of course, play an important role as food. The species listed below as numbers 1, 3 and 6 were observed in the stomachs of Beluga taken at Les Escoumains in 1939; the others were found in Beluga from the Manicouagan Bank in 1938: 1. Eelpout - 6 skeletons in all, each about 10 inches long, were taken from 2 stomachs; 2. Sea snail - in all, 4 packets of eggs of this small fish were found in 4 stomachs; 3. Blenny - fragments of a skeleton, about 11 inches long, observed in one stomach; 4. Lamprey - several corneous teeth of the suctorial disc were taken out of 2 stomachs; 5. Hake (Figure 14) - a young individual, about 6 to 7 inches long, found in one stomach; 6. Lumpfish (1) - 1 specimen, about 12 inches long, taken from one stomach; (1) The Cyclopterus lumpus is called poule d'eau (water hen) at Les Escoumains; however, according to Prat ( 1933, p.109) it is known as poule de mer (sea hen) at Trois-Pistoles. 0 • Fig. 25. Structure of capsules for two different types of skate eggs (Vladykov, 1936): a) R. senta; h) R. radiata. 7. Skate (Figures 24 and 25) - fragments of 11 egg capsules belonging to two species (R. radiata and R. senta) were observed in 6 stomachs. Details on the differentiation of egg capsules of the skate of eastern Canada can be found in an article by Vladykov (1936). O - 84 - • Invertebrates Besides fish, we found several specimens belonging to different groups of invertebrates (Tables IX) in the stomachs of Beluga. The following are the main groups in order of importance: polychete worms (Nereis), decapod crustaceans (shrimp) and cephalopod mollusks (squid and octopus). • FIGURE 26 - Two clam worm or "bloodsucker" (Nereis virens) specimens: the preferred food of Beluga young and females. O - 85 - Clam worm or Bloodsucker (figures 26 - 28) - Nereis virens is a very widespread polychete worm in the salt waters of the St. Lawrence and in the Atlantic. It can attain a length of 8 to 12 inches and be as big around as the little finger. The body is greenish brown, somewhat iridescent, and the legs (parapodia) are a reddish colour (Fig. 33). Some data on the size of this worm, as taken at Les Escoumains and measured after fixing in formol, are given below: LENGTH WEIGHT VOLUME (mm) (g) (cc) 60 1.3 1.2 77 2.8 2.6 93 1.7 1.5 9 105 2.3 2.2 108 3.4 3.0 119 3.0 2.7 125 4.2 3.7 150 5.5 3.7 186 9.8 9.1 Mean: 114 3.8 3.4 (42 in.) (0.14 oz.) (0.21 cu. in.) Salt-water anglers are quite familiar with the Nereis, particularly in Trois-Pistoles, where it is known as the sangsue bloodsucker. They collect them at low tide from under stones and use them as bait for smelt. The soft body of Nereis is easily digested and only the two hook-shaped mandibles remain in the Beluga's stomach. It is these S chitinous crotchets (Figure 28) that allow us to count the number of - 86 - O worms eaten. During August and September, the Nereis is one of the principal food sources of the Manicouagan Bank Beluga (Table XV); we removed it from 64 stomachs, i.e. 60 percent of our specimens. The number of these worms per Beluga stomach varied from a few individuals to 1,400. Although Beluga of both sexes eat Nereis, pregnant or nursing females show a marked preference for this type of food. The following table gives the maximum quantities of these worms taken from Beluga stomachs: • BELUGA Nereis # SEX LENGTH DATE OF CAPTURE NUMBER OF NUMBER OF (in.) CROTCHETS INDIVIDUALS Young Beluga 110 '. 1051 2. IX.38 131 66 113 e 1131 2. IX.38 55 28 124 94 9. IX.38 61 31 137 1191 11. IX.38 (4 59 30 Adult Beluga 70 161 '. 4.VIII.38 2.222 1,111 101 127 30.VIII.38 2.732 1,366 111 151 2. IX.38 2.469 1,235 121 149 8. IX.38 1.255 628 107 cf-, 172 31.VIII.38 60 30 333 ce, 1291 3. XI.39 50 25 O - 87 - None of the authors cited in this publication mention Nereis in the diet of the Beluga. However, Russian hunters in the Sea of Barentz have observed that Beluga eat a great number of certain marine worms. The exact identity of these worms is not known: Tschirkowa & Folitarek (1939, P. 113), on the basis of information from hunters, believed that the worms belonged to the species Arenicola marina, although they could well be Nereis. Among other polychete worms, we removed specimens of the species Cistenides gouldii (1) from 21 Beluga stomachs. These are small marine worms half an inch long, with a sheath of sand. C. gouldii was • found in small quantities: the maximum number taken from a single stomach (female #111) was 23 individuals. Squid (Figures 29-33) - Known by the scientific name of Illex illecebrosus (2), the individuals of this species which we removed from Beluga stomachs were usually 7 to 8 inches long, not counting their tentacles. This migratory species of cephalopod mollusks visits our region in summer when the water has warmed up (1)Préfontaine (1932, p.207) gives a list of Polycheta from the Trois-Pistoles region of the St. Lawrence River. (2) In one of our communications to the ACFAS conference (Vladykov, 1940, pp. 120-121), we mentioned the presence of this species in Beluga food. Meanwhile, two years later, Préfontaine and Philippe (1942, p.112) again mentioned I. illecebrosus in the additions to • the list of mollusks of the St. Lawrence estuary. - 88 - enough, and thus is a food source for the Beluga mainly in August and September. It is seldom found in stomachs removed in the I , ri ritplfirl iiiii ---- Irilipp n rurroTrrfp -rri 1 i ri 1 ! • 21 1 lirrrp FTTTITtliTrii frp411- . ri ti trill-111 _, .. _ .,, _ . . t Al « •CANAPIAN .A•01Pii■TORY SUPPLIÊS. LIMITE- f _ ----...... ____,-.. ______ • 0 I - .______..__ FIGURE 27 - 2,732 buccal crotchets, corresponding to at least 1,366 clam worm individuals (Nereis virens), taken from the stomach of a female Beluga 10 feet 7 inches long (#101). O -89- FIGURE 28 - Different views of the buccal crotchets of the clam worm (Nereis virens) beginning of summer as, for example, in our samples from Les Escoumains. 0 - 90 - In all, 35 stomachs or 33 percent of our samples contained squid (Tables X and XVIII). Female Beluga in particular preferred this food (Table XVI). The greatest numbers of squid taken from Beluga stomachs are: BELUGA SQUID # SEX LENGTH DATE OF CAPTURE NUMBER OF (in.) MAN- INDIVI- CRYSTAL- INDIVI- DIBLES DUALS LINS DUALS 93 130 25.VIII.38 197 99 153 77 121 149 8. IX.38 251 126 - - 91 169 23.VIII.38 164 82 105 53 92 130 23.VIII.38 89 45 - - 94 6N 176 27.VIII.38 40 20 - - Octopus (Figures 34 & 35). Dr. P. Barsch and Dr. H. Rehder of the National Museum in Washington identified the octopus mandibles taken from Beluga stomachs as those of the species Bathypolypus obesus (Verrill). Although the vertical distribution of this octopus is not well known (Robson, 1932, pp.299-300), its presence in the stomachs of Beluga leads us to believe that it does frequent shallower waters, at least in the St. Lawrence River. From our samples, we determined that B. obesus, which we removed from only 21 stomachs, is a less important food than squid. The 0 - 91 - • FIGURE 29 - Dorsal view of a squid (Illex illecebrosus), a prized food of Beluga young and females. O - 92 - • FIGURE 30 - Ventral view of the squid (Illex illecebrosus) in Figure 29 - 93 - following table gives the maximum number of octopus taken from Beluga stomachs: BELUGA OCTOPUS # SEX LENGTH DATE OF CAPTURE NUMBER OF NUMBER OF (in.) MANDIBLES INDIVIDUALS 46 d 170 20.V11.38 17 9 111 c4 151 2. IX.38 23 12 121 149 8. IX.38 24 12 Another species of octopus, Bathypolypus arcticus Prosch (1), is found in the deep waters of the St. Lawrence (Préfontaine, 1933, p. 257) and the Atlantic (Verrill, 1882, pp. 185-191). Because of its • depth distribution, the Beluga cannot catch this species and thus none occur in our food samples. The Beluga of European waters also feeds on Cephalopods (Freund, 1932, p.43). Similarly, two other cephalopod mollusks have been identified in the diet of North Pacific Beluga: Onychia bergii and O. kamtschatica (Heptner, 1930, p. 57). Lamellibranchia - These bivalve mollusks are commonly known as moules (i.e. mussels) (2). Individuals belonging to at least (1) Some authors refer to this same species as Octopus bairdii (Verrill) (2) At Les Escoumains, the different types of Lamellibranchia are known as mouques rather than the more usual moules. O -94- seven species (Table IX) were found in our food samples; among these species (1), Mesodesma arctata was found in 8 stomachs and M. deaurata in 6. However, Cystodaria siliqua was found in the greatest numbers: 14 individuals (Beluga #111) and 19 individuals (#70). Generally, only one or two mussels were found per stomach thus indicating that they are not important food for Beluga in our region. Without taking into account the different species, Lamellibranchia (2), as a group, were removed from 37 stomachs or 35 percent of our samples (Table XVIII). Gastropods or Snails - These mollusks do not play a significant role in the diet of the St. Lawrence River Beluga. In all, only 19 stomachs contained them (Table XVIII). The whelk (Buccinum undatum) (3) and the periwinkle (Littorina) both inhabit coastal waters. Whelk opercula were found in 10 stomachs of Beluga from the Manicouagan Bank. However, we do not know whether the Beluga ate the snails whole, or whether the opercula were accidentally picked up from the bottom. (1 ) Préfontaine (1932, p.209; 1933, p.257) gives a list of Lamellibranchia collected in the St. Lawrence estuary mainly in the Trois-Pistoles region. We can add three other species to this inventory: Cystodaria siliqua, Mesodesma deaurata and Yoldia limatula, all taken from Beluga stomachs in 1938. (2) Arsenyev (1939, p.30) mentions the occasional presence of mussels (Mytilus edulis) in the Beluga of the North Pacific. (3) The egg mass of this species is round and 3 to 5 inches in diameter. The hunters of Les Escoumains confuse them with eelpout eggs (Zoarces anguillaris). - 95 - O FIGURE 31 - The 251 mandibles above correspond to at least 126 squid (Illex illecebrosus), found in the stomach of a female Beluga 12 feet 5 inches long (#121). • I • " I 6mm. FIGURE 32 - Different views of whole crystallins (above) and half crystallins (below) from the eyes of squid (Illex illecebrosus), found in the stomach of a Beluga. The contours of these crystallins are somewhat deformed by digestion. • FIGURE 33 - Comparison between fish and Cephalopod eye crystallins: a) cod (Gadus callarias); b) squid (Illex illecebrosus). • * - 97 - O FIGURE 34 - Ventral view of an octopus (Bathypolypus obesus), a common food of Beluga. e - 98 - ‘111 FIGURE 35 - Beaks of two types of Cephalopods ta ken from Beluga S nun. stomachs: above, an octopus beak (Bathypolypus obesus), and below, a squid beak (Illex illecebrosus); S) superior mandible; I) inferior mandible. • - 99 - • ! • ■ at< ■ • •• X f! y ; - * Lime ;et ! u,sede Fig. 36- Over five pounds of sand and 2,222 Nereis crotchets found in the stomach of a female Beluga 13 feet 5 inches long (#70). Beluga pick up a great deal of sand as they seize Nereis on the bottom. O - 100 - Decapods - These crustaceans were found in 69 stomachs or 65 percent of our samples (Tables XVIII). Among the decapods found were remains of crabs and some species of shrimp (Argis, Crago, Pandalus, etc.) (1). Generally speaking, shrimp are much more important than crabs in the diet of the St. Lawrence Beluga. This is particularly true of the Saguenay region. The rather soft body of shrimp is easy to digest and thus it is almost impossible to determine the exact number of individuals eaten by the Beluga. Nevertheless, the following tables give the maximum quantities of shrimp taken from stomachs: BELUGA SEX LENGTH DATE OF CAPTURE NUMBER OF SHRIMP (in.) • MANICOUAGAN BANK 1938 46 170 20. VII 19 74 1032 9.VIII 23 121 149 8. IX 16 LES ESCOUMAINS 1939 303 139 25. VI 32 304 159 26. VI 54 306 136 30. VI 57 309 111 8.VII 113 315 112 31 VII 197 (1) Given the poor state of preservation of the shrimp, it is quite difficult to identify the traces of several species with any certainty. However, we did find traces of Pandalus montagui, a drawing of which is on the frontispiece of this publication. Information on St. Lawrence decapod crustaceans can be found, for example, in the following sources: Rathbun (1929), Préfontaine (1932, pp. 207-208; 1933, p.256) and Fiset (1934). 0 - 101 - Heptner (1930, p.57) and Birula (1934, p.15) mention that in European seas, the following decapods have been found in the food of Beluga: Hippolyte, Crangon crangon and Pandalus borealis. According to Arsenyev (1939, p.29), Crangon septemspinosa and Upogebia issaeffi are found in the Beluga of the North Pacific. Amphipods - These small crustaceans, half to one inch in length, called chevrettes at Les Escoumains, were found in 37 stomachs or 35 percent of our samples (Table XVIII). Below are the maximum numbers of amphipods found in stomachs: BELUGA • SEX LENGTH DATE OF CAPTURE NUMBER OF AMPHI PODS 304 159 26. VI.39 187 308 138 4. VII.39 54 65 160 3.VIII.38 65 140 14.4 23. IX.38 51 It is hard to determine whether Amphipods taken from stomach boluses were eaten by the Beluga themselves or by the fish they later swallowed. (1) However, the abundance of Amphipods in areas like the Saguenay region leads us to believe that Beluga feed directly on them, at least at certain times of the year. (1) It is well known that caplin, tomcod and other fish making up the main diet of the Beluga often feed on Amphipods and other small crustaceans (Pigeon & Vallée, 1937). Ô - 102 - Fig. 37 A granit cobble weighing 7 lbs, found in the stomach of a male Beluga 13 feet 8 inches long (#85) • Other Croups - Occasionally, other minute crustaceans like Copepods, Cumaceans, Schizopods, etc., were found in Beluga stomachs. The presence of these crustaceans can be explained by the fact that they are food for fish eaten by Beluga and are not swallowed directly by the latter. Sometimes, coelenterates, tunicates and other marine groups were discovered in the stomachs of Beluga. Interestingly, although Echinidae like starfish, urchins, etc., are abundant in the regions studied, no individual from this group was found in stomach boluses. Apparently, the Echinidae are not a part of the Beluga's diet. Seasonal variations The question of seasonal variations in the composition of the - 103 - Beluga's food is important. If, for example, the Beluga eats large • amouts of a certain (commercial) fish in one season of the year, it is often concluded that just as much is eaten through the rest of the year. This is undoubtedly why the presence of a salmon or cod in a White Whale's stomach has convinced some people that these fish are consumed year round. Unfortunately, we do not have data for each month of the year; however, the information compiled from June to September 1938 on the Manicouagan Bank is suffificient to prove that the diet of the Beluga varies from one season to another. 0 June Juin July ju illet AugustL,.,,.t Septembre September 0 FIGURE 38 - Monthly variations of percentage of stomachs containing principal fish species. The Béluga were caught on the Manicouagan Bank in 1938. - 104 - Indeed, in June and July, Beluga ate caplin almost exclusively while in August and September, launce and flounder made up the main part of their diet (Table XV and figures 38 and 39). The case of Nereis and squid is interesting. Although these invertebrates are eaten throughout the summer, they are an important part of the Beluga's diet only in August and September (Figure 39). The species most important in frequency and quantity to the diet of the Beluga occur only in certain seasons. On the other hand, species like crustaceans, Lamellibranchia, certain fish (sculpin, etc.) that complement the normal diet, are present all year although in small quantities. • The seasonal variations in the alimentary regimen of Beluga are probably caused by a particular abundance of certain fish or other aquatic groups at specific times of the year. Regional variations As indicated before, the presence of certain foods in the Beluga's stomach bolus depends not only on the season but also on location. Since our material was taken from three different locations, we will describe the Beluga diet on that regional basis. Manicouagan Bank - Most of the Belugas studied were from this bank; 88 stomachs containing food were obtained in 1938 and one in 1939 (Tables XVI and XVIII). - 105 - The feeding habits of the Beluga on the Manicouagan Bank are characterized by the absence of salmon and the presence of very small quantities of Decapods. Other characteristics such as the amount of flounder, Nereis and squid probably result from the fact that the Beluga were caught during favorable seasons for these species. There is no variation in the composition of the stomach bolus of Beluga caught in difficult parts of the Manicouagan Bank such as the White Bank, Green Bank and Clay Bank. This is understandable because those sections are not far from each other. In addition, we do not know how long it takes for the Beluga to digest its food, and the same • individuals probably visit several parts of the Manicouagan Bank on the same day. Thus, their food would represent a mixture of different organisms from more than one location. Generally speaking, the Manicouagan Bank with it shallow water and bottom favorable to the proliferation of a variety of organisms, is ideal for female and young Beluga. Les Escoumains - Only 16 stomachs containing food were collected in this location, mainly in June and July (Tables XVII and XVIII). The distinguishing feature of this region is its cold, deep water where an abundance of shrimp and a species of deepwater flounder e (Glyptocephalus cynoglossus) are found. - 106- Due in all likelihood to the proximity of the Saguenay estuapy, salmon are more common here: one salmon was removed from a stomach. Percentage of stomachs Nereis 80 0 rere:1 Nereis Yam 60 o me Ilnoornot- squid 40 we Od Wu CieW11 W o Lao 1■• o June Juin July Juillet August.aoet Septembre September FIGURE 39 - Monthly variations in the percentage of stomachs containing the principal invertebrates. These Beluga were caught on the Manicouagan Bank in 1938. - 107 - Rivière-Ouelle - Only 2 stomachs containing food were obtained here (in November) and thus no definitive conclusion could be drawn from such limited data. Quite probably, the lateness of the season is the reason for the absence of caplin, launce and commercial fish. According to local fishermen, Beluga eat eel in the autumn (1). In concluding this sub-chapter, we should restate that, in areas other than those studied, the Beluga diet could consist in part of fish not indicated in Table VIII. However, these local variations do not change the conclusion that the most important Beluga food fish are caplin and launce. Indeed, caplin are the principal food of the • Beluga even in the Arctic seas of Europe (Heptner, 1930, p.20; Freund, 1932, p.43). Dietary Variations according to Age and Sex In the calf stage of growth, the Beluga is sustained exclusively by its mother's milk. When the young Beluga is almost weaned and is about 80 inches long, it begins to take its own food (Table VII). (1) The importance of eels in the Beluga diet will be discussed in the following chapter. O - 108 - In the second year, in the Blue Calf stage, it livès entirely on 0 what it finds in its aquatic environment. Small fish like caplin, launce, shrimp, Nereis, etc., are its main food. The narrow gullet of a young Beluga under 10 feet prevents it from swallowing large fish. For this reason, only 3 young Beluga stomachs, or 15.6 percent of our samples, contained traces of cod (Table XVI). It should also be noted that the composition of the food of young individuals does not differ between the sexes. The diet of the Greyish-white Calf, three to four years of age, is generally similar to that of older individuals. Thus, as the following figures indicate, the difference between the food of male and female Greyish-white Calves is just as pronounced as among adults: FOOD OF THE BELUGA PERCENTAGE OF STOMACHS (1) MALE FEMALE Launce ...... 45.0 82.7 Sculpin ...... 37.5 31.0 Cod ...... 52.5 41.5 Squid ...... 37.5 48.2 Nereis ...... 40.0 75.8 Decapods ...... 57.5 82.7 (1 ) This data was taken from Table XVI. The total number of Beluga stomachs of each sex is taken as 100, and the percentage of stomachs with a certain type of food is calculated on this base. However, the sum of the percentages in this table exceeds 100 because each stomach contains several types of food. 0 - 109 - Males prefer bigger fish like cod and sculpin while the smaller females eat small animals like launce, squid and, above all, Nereis. In August and September, Nereis are abundant on the Manicouagan Bank. The variations in the maximum numbers of Nereis taken from the stomachs of Belugas of different size and sex are quite pronounced: young Beluga (1) contained 30 to 60 specimens, adult males contained 25 to 30 specimens, adult females, 623 to 1,377 specimens. Not only the composition of the food, but also the weight of the stomach bolus varies between young and adult Belugas of both sexes (Tables XX- XXII). The average weight of the food removed in 1938 varies in the following way: BELUGA AVERAGE WEIGHT OF FOOD PER STOMACH(2) MINIMUM MAXIMUM AVERAGE (oz.) (oz.) (oz.) Young of both sexes ...... 22.7 35.3 30.3 Adult females ...... 29.1 59.4 39.4 Adult males ...... 31.5 60.4 44.1 (1) Individuals under 10 feet in length (2) Sand and stones are not included in this table 0 - 110- Correlations between the abundance of food and the thickness of blubber In a previous publication (Vladykov, 1944, pp.73-76), we already pointed out that the thickness of Beluga blubber varies with itssize and the season. An index of condition was proposed in order to best express an abundance or paucity of fat in a Beluga. This index gives the relationship between the thickness of the blubber and the total length of the animal and is expressed as a percentage: the higher the index, the more blubber on the Beluga and vice versa. • By dividing the weight of the food (1) in grams by the length of the Beluga in centimetres, a relationship called the index of repletion is obtained (Tables XX - XXII). A comparison of the index of condition and the index of repletion for the same months reveals a direct correlation between these two values. Table XXIII gives details of this correlation for Beluga of different sizes. This correlation implies that the Beluga organism has a physiological ability to transform food into fat in a short period of time (Table XXIII). Thus, when food is more abundant (in June and September), the adults have more fat. For young Beluga, food is most abundant in June and August and consequently the index of condition is higher in these two months. (4) Sand and stones, not being food, are not included. O - 111 - THE BELUGA AND COMMERCIAL FISH The relationships between the Beluga of the St. Lawrence River and certain fish of commercial value remain to the studied in this chapter. If cod, salmon and other important fish are found in many stomachs, Beluga may be considered a dangerous destroyer of our fish. If, however, it can be established that a limited number of Beluga feed on commercial fish and do so only in certain months, then they should not necessarily be considered harmful to our fisheries. TABLE XIX.- Quantities of different species of fish caught in a weir near Point Manicouagan in 1938 CA- STUR- HER- PLIN SMELT GEON RING LAUNCE TOMCOD FLOUNDER COD Date • lbs lbs lbs lbs lbs lbs lbs nbr May 29-31 1 440 0 2 0 38 170 0 June 1-30 23 3,204 59 1,191 409 986 2,709 0 July 1-31 0 2,141 247 1,889 615 578 1,369 4 Aug. 1-31 0 1,382 41 179 83 128 680 136 Sept.1-30 0 6,052 0 1,272 228 1,551 1,247 50 Total ... 24 13,219 347 4,533 1,335 3,281 6,185 190 Cod in the Alimentation of the Beluga Since, among the important fish, only cod was found in Beluga stomachs with great frequency, the greatest detail will be devoted to this fish (1). Identification - With only one exception (Beluga #85), cod taken from the stomachs of Beluga were in a very advanced state of digestion. Thus, various types of remains were used to identify these (1) Note that in European waters, the Beluga has also been found to eat cod (Collett, 1906; Freund, 1932, p. 43; Heptner, 1930, p.55). O -112- I T I i I I -r-- ._- ,- T- 100 Msk1ee a.reis E3 femelles . :;. jeunes LO C3 total .:. • 0 100 =aoo rnet 60 0 Morue 0 Lo t- 100 Langon 0 E l I 100 Oapelcn 60 Juin Juillet Aotlt Septembre Juin - 'erotembiv FIGURE 40.- Fluctuations in the percentage of stomachs containing the principal types of food according to season, size or sex for Beluga taken on the Manicouagan Bank in 1938. - 113 - fish: parts of the skeleton, otoliths, crystallins and also the Lernea branchialis parasite (Figures 14-18). Although the presence of this parasite in the stomach of the Beluga can indicate that cod was eaten, the number of L. branchialis does not determine the quantity consumed. In fact, several parasites can be found simultaneously on the gills of a single cod. In all, cod were identified by fragments of L. branchialis in 13 Beluga stomachs. As already explained in the subchapter Identification of Species, L. branchialis is only tentatively considered a specific parasite of the common cod (Gadus callarias). There is always the possibility that this parasite is also found on Greenland cod (G. ogac), a species that has not yet been studied in depth. TABLE XX.- Monthly variations in the "index of repletion" for young Beluga taken in 1938 on the Manicouagan Bank. NUMBER OF AVERAGE AVERAGE WEIGHT OF FOOD (g) (1) STOMACHS LENGTH WEIGHT MONTH WITH OF OF LENGTH OF BELUGA FOOD BELUGA FOOD (cm) (cm) (g) June 4 263 890 3.4 July 6 239 645 2.7 August 3 248 1,004 4.0 September 6 282 903 3.2 Total ... 19 258 861 3.3 • It is not always easy to distinguish between fragments of common cod and Greenland cod taken from the stomach of the Beluga. This is particularly true of the crystallins and, in many cases, the otoliths (1) In Tables XX-XXII, the figures in this column represent the quotient obtained by dividing the weight of the food (in grams) by the length of the Beluga (in centimetres). O - 114- and even bones. (1) This difficulty in identification should be kept in mind when reading the text that follows. In the tables in the Appendix, cod crystallins taken from the stomachs of Beluga are not separated from the otoliths. This information is thus given below: BELUGA NUMBER OF DIFFERENT PARTS OF COD # SEX LENGTH BONES OTOLITHS CRYSTALLINS L. branchialis (in.) 12 d 150 6 - 9 1 33 e 149 - - 1 - 42 e 139 - - 1 - 44 136 - - 1 - • 46 170 _ 1 4 - cr 55 cr 165 - - 1 2 65 oie 163 9 120 28 4 67 CP 160 10 73 9 5 69 Cr 169 8 104 12 1 76 ér 167 - - 14 2 91 e 169 - - 7 - 96 e 168 2 3 2 - 108a ? ? 15 72 34 2 136 c l 176 - - 1 - 336 136 - - 2 - % (1) In the case of one male Beluga (#6, Table XXIX), one tooth alone identified the presence of cod; and, in the case of a female (#75, Table XXVII), one vertebra. These two structures may belong to either common cod or Greenland cod. O - 115 - In six cases in the above table, cod was identified by crystallins only; in one case (Beluga No. 55), by 1 crystallin and 2 fragments of L. branchialis; in another case (Beluga No. 46), by 4 crystallins and 1 otolith. In these eight stomachs, it was the crystallins that permitted identification of this type of fish. However, these crystallins may belong to either the common cod or the Greenland cod. In general, in 1938 and 1939, the Beluga stomachs containing cod (of both species), identified by the different fragments, were distributed in the following way: BELUGAS NUMBER OF STOMACHS WITH TRACES OF COD IDENTIF ED BY (1) bones otoliths crystallins L. branchialis Total 0 Young (2) 1 1 4 6 Females 5 3 2 6 16 Males 13 1 6 3 23 Total 19 5 8 13 45 u_ Having eliminated the cases of doubtful identification, there remain 22 stomach containing traces of common cod COMMON COD NUMBER OF STOMACHS identified by bones 17 identified by otoliths 5 (1) If, in the same Beluga stomach, cod bones are found together with otoliths, or bones with crystallins, or with L. branchialis, this stomach is listed under bones. But, when bon-es are not present, the traces of cod are listed under their respective names, i.e., otoliths, crystallins, or L. branchialis. (2) Belugas of both sexes, under ten feet in length. - 116- O Size and number of cod.- A method had to be found to evaluate the size of the fish on the basis of the fragments removed. An attempt was made to establish a relationship between the size of fish and the length of some of their cranial bones. Testing revealed that the premaxillaries are the most useful: there is a direct relation between the size of a cod and the length of its premaxillaries. The following table gives the results of the measurement of 30 premaxillaries belonging to 30 cod found in Beluga stomachs: COD BELUGA NO. NUMBER OF LENGTH OF ESTIMATE D VALUES • INDIVIDUALS PREMAXILLARY MIN. MAX AVERAGE LENGTH WEIGHT (in. )(in.) (in.) OF FISH OF FISH (in.) lbs.-oz. 69 1 0.59 0.59 9 0-4 67 and 69 4 0.67-0.79 0.72 11 0-6 12 and 67 2 1.29 1.29 20 3-0 67 2 1.40-1.42 1.41 22 4-0 52, 67 and 94 4 1.54-1.61 1.57 23 4-6 67, 69 and 94 4 1.69-1.73 1.70 25 5-6 52, 67 69 and 94 5 1.81-1.89 1.85 29 8-0 12, 69, 85 and 94 4 2.01-2.09 2.05 30 8-6 52, 85 and 94 3 2.20-2.28 2.22 32 9-6 67 1 2.44 2.44 34 12-0 - 117 - From the above table, it is clear that the Beluga only eats young cod. As a supplement to this table, it should be mentioned that 5 cod were removed from the stomach of a 13 foot, 8 inch male Beluga (No. 85). The largest and best preserved of these cod, relatively unaffected by digestion, was 30 inches long and weighed 10 pounds. The number of cod, estimated by the traces removed from the stomachs varies according to the type of structure used for the estimation, as indicated in the following table: MALE BELUGA NUMBER OF COD ESTIMATED BY NUMBER OF L. branchialis NO. LENGTH DATE OF BONES OTOLITHS CRYSTALLINS (in.) CAPTURE 1938 12 150 27. VI 6 5 65 163 3.VIII 9 20 14 67 160 3.VIII 10 12 4 69 169 3.VIII 8 17 6 76 167 9.VIII - 7 85 164 19.VIII 5 1 94 176 27.VIII 7 3 108a ? ?.VIII 15 12 17 2 The above table gives the maximum quantities of cod by individual stomach. Males always eat more of this fish. The largest numbers of cod in a single Beluga stomach, as identified by the different structures, were 20 (by otoliths), 17 (by crystallins) and 15 (by bones). It is not known, though, whether these cod were all eaten during the same meal or whether they represent an accumulation 0 - 118- s of residue from several meals. It should be added that not one Beluga stomach contained cod only: other fish or invertebrates were always found with cod. This indicates that, for the Beluga, even the adult male, the cod is not the "pièce de résistance" of meals, but rather, a supplement to other important foods (for details, see the tables in the Appendix). Information on the average number cod eaten by Beluga of both sexes and of different sizes is given in Table X. TABLE XXI.- Monthly variations in the "index of repletion" for female Beluga caught in 1938 on the Manicouagan Bank. MONTH NUMBER OF AVERAGE AVERAGE WEIGHT OF THE FOOD (g) STOMACHS LENGTH OF WEIGHT OF WITH FOOD THE BELUGA THE FOOD LENGTH OF THE BELUGA (cm) (cm) (g) June 0 - - - • July 8 345 827 2.4 August 11 341 845 2.5 September 10 344 1,687 4.6 Total 29 343 1,120 3.2 Variations according to the sex of the Beluga.- Beluga of different sexes and sizes have different preferences for cod (Table XVI). For example, the frequency of cod in the stomachs of Beluga caught on the Manicouagan Bank in the summer of 1938, is the following: Young Beluga (1) 3 stomachs out of 19 (16%) Female Beluga 12 stomachs out of 29 (4 )%) Male Beluga 23 stomachs out of 40 (53%) (1) Beluga of both sexes, less than ten feet long. O - 119- Unfortunately, it was not possible to collect an equal number of Beluga stomachs of the two sexes and of different sizes. As explained in the previous study (Vladykov, 1944, p. 98), the high number of males killed in 1938 on the Manicouagan Bank is due to the hunting method: the males are much easier to catch when they are pursued by motorboat. This gives the false impression that there are more males, at least on the Manicouagan Bank, than females or young. Therefore, the high number of adult male stomachs leads to the belief that the Beluga, in general, regardless of size or sex, eats cod regularly when, in fact, this erroneous impression is caused by an • incomplete sampling of the food of the Beluga. Seasonal variations.- The study of samples collected in 1938 (Tables XII-XIV) demonstrates that the importance of cod as food for Beluga also varies with the seasons: NUMBER OF STOMACHS CONTAINING COD MONTH BELUGA TOTAL 0/ young females males Number /0 June 2 2 5.6 July 1 2 5 8 22.2 August 1 7 13 21 58.3 September 1 3 1 5 13.9 Total 3 12 21 36 100.0 O - 120 - Although the Manicouagan Bank is not known as a cod-fishing area, a certain quantity of these fish visit the Bank in the summer. In 1938, near Pointe Manicouagan, a small weir was constructed to catch different types of fish. Smelt, flounder, herring (adult or sardine) and sculpin were among the fish caught in marketable quantities (Table XIX). The total number of cod was only 190, of which most were young specimens: COD (1) MONTH NUMBER June 0 0 July 4 2.1 August 136 71.6 September 50 26.3 Thus, in the weir, as in the stomachs of Beluga of the Manicouagan Bank, cod were most abundant in August. Because of the selective sampling of Beluga, the largest number of adult male stomachs was collected in August. This gives, once a gain, the impression that the Beluga eat more cod than is, in fact, the case. The following table, based on the number of food-containing stomachs collected on the Manicouagan Bank in 1938, provides a summary: 0 - 121 - NUMBER OF BELUGA STOMACHS MONTH YOUNG FEMALES MALES GRAND TOTAL WITH TOTAL WITH TOTAL WITH TOTAL WITH TOTAL COD COD COD COD (2) (2) (2) (2) June 0 4 0 0 2 9 2 13 July 1 6 2 8 5 10 8 24 August 1 3 7 11 13 16 21 30 September 1 6 3 10 1 5 5 21 Total 3 19 12 29 21 40 36 88 16.0 100.0 42.0 100.0 53.0 100.0 41.0 100.0 (1) Unfortunately, we did not have the opportunity to examine the cod and thus do not know whether they belong to the species G. callarias. The owner of the weir did not know the distinction between the common cod and the Greenland cod. • (2) In our cod sampls, the two species G. callarias and G. ogac, withoug a doubt, were intermixed. 0 - 122 - In the vicinity of Les Escoumains in June and July 1939, although according to all information cod were absent, it was determined indirectly that this fish was present in 9 out of 16 stomachs of Beluga caught in that area. In 8 of the 9 cases, the presence of cod was determined by the remains of L. branchialis. The chitinous fragments of this parasite are not easily attacked by digestion and can be extant in the stomachs for quite some time. There are thus two possibilities: that the Beluga had swallowed L. branchialis with its host the common cod (G. callarias) elsewhere before coming to Les Escoumains; or, that the host of this parasite was actually the Greenland'cod (G. ogac), a species living along the North Shore • (Vladykov, 1945, p. 29). This last hypothesis seems more plausible because in the preceding year, common cod were virtually absent in June and July from the Manicouagan Bank, which is even further north-east than Les Escoumains. As far as we know, the common cod arrives first in the Gulf of St. Lawrence and then gradually advances west. Summary - In concluding the present sub-chapter, the information on cod removed from the stomachs of Beluga should be summarized. In 1938 on the Manicouagan Bank, cod were found in 36 of 88 stomachs whereas in 1939 in the vicinity of Les Escoumains, the ratio was higher, namely, 9 stomachs out of 16. In all, the remains of cod of both species were found in 45 stomachs or 42% of our samples (Table XVIII). O - 123 - Although the ratio of cod in the food of the Beluga may appear to be high (42%), such is not the case. As already explained in the beginning of this sub-chapter, in 23 stomachs containing the remains of cod (crystallins, fragments of L. branchialis and bones), accurate identification of the species was impossible. Thus, the presence of common cod (G. callarias) was confirmed in only 22 stomachs or 20.6% of our samples. The selective sampling of adult male Beluga made it seem that the number of stomachs containing cod was higher than in reality. Furthermore, even among the male Beluga, the greatest number of samples was obtained during the month of August. It should be kept in • mind that, in August, at least on the Manicouagan Bank, there were more young cod both in the water and the stomachs of Beluga. Therefore, the sampling of a larger number of stomachs in the month of August increased the overall ratio of cod in the food. TABLE XXII.- Monthly variations in the "index of repletion" for male Beluga caught in 1938 on the Manicouagan Bank. MONTH NUMBER OF AVERAGE AVERAGE WEIGHT OF THE FOOD (g) STOMACHS LENGTH OF WEIGHT OF WITH FOOD THE BELUGA THE FOOD LENGTH OF THE BELUGA (cm) (cm) (g) June 9 391 1,357 3.5 July 10 383 1,050 2.7 August 16 412 894 2.2 September 5 379 1,715 4.5 Total 40 391 1,254 3.2 O - 124 - To illustrate all these points, the case of the adult male Beluga collected on the Manicouagan Bank in 1938 was analyzed: TOTAL NUMBER OF STOMACHS WITH COD MONTH STOMACHS 0/ NUMBER /1) June 9 2(1) 22 July 10 5 50 August 16 13(2) 81 September 5 1 20 (1)The specific identification of the cod identified by a tooth in the stomach of Beluga No. 6 is not certain. (2) In one of these stomachs (Beluga No. 66), cod was identified by the traces of L. branchialis. • From this table, it is evident that the number of stomachs of Beluga containing cod depends, first of all, on the season of collection: if more samples had been taken in June and September, the overall occurrence of cod would have been considerably lower; the more numerous samples during the month of August appear to increase the occurrence of cod. Thus, in order to judge the exact importance of the common cod as food for the Beluga, an equivalent number of stomachs of individuals of both sexes and of different sizes would have to be collected over twelve consecutive months. Salmon in the alimentation of the Beluga Fairly accurate information on the importance of salmon as Beluga e food is available only for the North Pacific. In fact, I - 125 - several authors, Heptner (1930, p. 58), Kellogg (1940, p. 72) and Arsenyev (1939), deal with this subject. Nevertheless, it should not be forgotten that the Beluga of the North Pacific,especially that of the Sea of Okhotsk, belong to a particular species (D. dorofeevi) which is larger than that of the St. Lawrence (D. leucas). It should also be recalled that several species (six) of North Pacific salmon, which are fished commercially, belong to a particular genus: Oncorhynchus, which is quite distinct from Atlantic salmon (Salmo salar). With the exception of Chinook salmon (0. tschawitscha), all the other varieties of Pacific salmon are quite a 0 bit smaller than Atlantic salmon. In addition, the individuals of all the Oncorhynchus species spawn only once in their life and die after reproduction. In order to reach their spawning-grounds, they enter the estuaries of rivers in schools considerably larger than those of their Atlantic counterpart, and are consequently much easier prey for the Beluga. Arsenyev (1939, p. 31) provides some interesting information on the diet of North Pacific Beluga. Among other food found in 102 Beluga of the Sea of Okhotsk, he observed the presence of only one species of Pacific salmon, 0. keta. Keta was found in 47 stomachs, i.e. 46°b of the sample. According to Berg (1932, p. 112), the average ♦ - 126 - weight of Keta is between 5 and 11 pounds. Before Arsenyev (1939) (1), some authors like Heptner (1930, p. 58) had also mentioned the presence of pink salmon (0. gorbuscha) in the food of the North Pacific Beluga. 0. gorbuscha, with an average weight of 4 pounds and an average length of 2 feet, is an even smaller species than 0. keta. Chinook (0. tschawitscha), the giant salmon of the Pacific, comparable in size to Atlantic salmon, was never identified in the food of Beluga. • TABLE XXIII.- Monthly correlations between the "index of condition" and "index of repletion" for Beluga caught in 1938 on the Manicouagan Bank. BELUGA Males Females Young INDEX INDEX INDEX MONTH OF OF OF OF OF OF CONDITION REPLETION CONDITION REPLETION CONDITION REPLETION June 4.21 3.5 5.26 - (2) 4.91 3.4 July 3.57 2.7 3.75 2.4 3.13 2.7 August 4.08 2.2 3.81 2.5 4.35 4.0 September 4.11 4.5 3.97 4.6 3.52 3.2 General 3.97 3.2 3.92 3.2 3.87 3.3 average (1) Arsenyev's interesting study (1939) contains a bibliography of 130 publications on the Beluga, mostly in Russian. • (2) No stomach with food. - 127- The literature gives few accurate data on the importance of Salmo saler in the diet of the Beluga: Tschirkowa and Folitarek (1930, p. 113), Freund (1932, p. 43) and Dmochowsky (1933, pp. 89-90) mention that according to the hunters, the Beluga of the northern part of Europe eats Atlantic salmon. In the St. Lawrence River region, our experience clearly indicates that the Beluga eats Atlantic salmon only in exceptional cases. Indeed, in the 107 stomachs examined, the remains of a single salmon were found in one stomach. The fragments of this rather young salmon were removed from a 13 foot 4 inch male Beluga (No. 304), caught on • June 26, 1939 at Les Escoumains. This rarity of salmon in the diet of the St. Lawrence River Beluga can be attributed to several reasons. Firstly, it should be noted that the salmon netted by the fishermen rarely weigh less than 10 pounds. According to Belding & Préfontaine (1939, p. 22), there are two common sizes of salmon in the Gulf of St. Lawrence commercial fishery: 10 to 11 pound "small salmon", and "large salmon", weighing about 21 pounds. There is no doubt that even the "small salmon" is too large for the small mouth and narrow gullet of our Beluga. Unlike the Pacific salmon, Salmo salar spawns at least twice in its life, and is thus much more vigorous when it approaches river - 128- for the spawning run. In addition, as judged by the yield of commercial fishing, the concentration of Atlantic salmon near the shore is less than that of Pacific salmon. To summarize, we can say that the frequency of salmon in the food of Beluga examined during 1938 and 1939 is equal to that of granite stones swallowed (Fig. 37) because both were found only once. To anyone who maintains that the Beluga destroys great quantities of salmon in the St. Lawrence River, the response should be that the Beluga eats granite just as often! Before concluding this sub-chapter, we should address the often-heard statement that the Beluga, if it does not actually eat the fish, it scares them off. For example, the presence of a herd of Beluga could frighten and disperse a school of salmon approaching the estuary of certain North Shore rivers and thus render net fishing less productive for some time. This is analogous to a motor launch which, when approaching the nets, frightens away fish. On the other hand, it is equally possible that salmon frightened by the Beluga (or boat) will be driven to the net: in this case, the Beluga would be the fisherman's benefactor! Herring and Eel in the Alimentation of the Beluga Although very little herring and not one eel was found in our - 129- samples of food, some details on the relationship between these two important fish and the Beluga would be useful. HERRING (Fig. 13).- This species was found in only two stomachs (Table VIII). In one case, a herring skeleton was removed from a 13 foot 3 inch male Beluga caught August 19, 1938 on the Manicouagan Bank. In the vicinity of Les Escoumains on August 2, 1939, an 11 foot 3 inch female (No. 316) was found to have swallowed several herring recently: at least 28 skeletons were removed from her stomach. The fact that European Beluga eat herring has been mentioned by II, Tschirkowa & Folitarek (1930, p. 113) and Birula (1934, p. 15). Arsenyev (1939, p. 29) made the saine observations on the Pacific Beluga. Ernest Boulianne, a Les Escoumains hunter, noted that, in spring, towards the end of May, Beluga feed on caplin and herring eggs. This time of year, the Beluga keep close to the shore where the caplin and herring are spawning. It is claimed that these fish are so frightened by the presence of the Beluga that they often jump out of the water and die on the beach. The local fishermen believe that the White Whale eats a lot of e herring in the spring in the Ouelle River estuary area and around • - 130 - Ile Verte, both of which are important herring spawning areas. However, it should be kept in mind that during the herring spawning season, there are also a lot of caplin in the same locations. It is interesting to note that the Beluga has a particular preference for caplin. The case of a 13 foot 9 inch male Beluga killed by Alphonse Dufour, a Les Escoumains hunter, on June 20, 1946 at the eastern end of Ile Verte, illustrates this point. That year, as before, young and adult herring were present there throughout June: on the 20th, about 50 yards from the spot where the Beluga was killed, a large quantity of sardines and herring were caught in a weir. • The stomach bolus of this Beluga weighed 10 pounds and was composed of tiny silvery fish. After a detailed laboratory analysis, 189 caplin, 1 flounder bone and 3 chitinous Nereis crotchets were identified, but there was no trace of herring. In summer, when there are no caplin near the shore and launce are not abundant, the Beluga eat more herring as the food samples indicate. EEL (Fig. 23).- It is often said that the Beluga eats eel. Ernest Boulianne reports that in the fall, when eel swim towards the ocean, I the Beluga, in order to catch them, stays in the area of Cboulements - 131 - near Ile-aux-Coudres and other locations where eel are congregate. The concentration of eel near the Ouelle River estuary in autumn coincides with the reappearance of Beluga there. nmile Lizotte, owner of a Beluga weir in this location, told us that the Beluga eat eel. During our visit to the Ouelle River in November 1938, we examined an eel caught in the weir. The eel had white vertical marks which were probably made by the teeth of a Beluga which had caught it and then let it slip away. There was no sign of eel in our Beluga food samples. Our knowledge of this fish leads us to believe that the Beluga eat it only e on rare occasions. In the summer months, only small eel (including adult males, which are always much smaller than females) stay in the saltwater areas near shore. The eel, a nocturnal fish that conceals itself in mud, under stones, etc. during the day, emerges only at night to hunt, and never strays far from its "burrow". As a result, even if the Beluga searches for them, eel are difficult prey. When mature eel head for the sea in the fall, they have fattened a great deal and may swim near the surface, according to fishermen's observations. (1) (1) Similar observations were made by Roule (1937) and Miss Callemand (1943) regarding European eel running to the sea. dr - 132 - However, these mature eel (females) descending the freshwater streams are quite sizeable fish. We took the following measurements of 1 487 eels captured in the Quebec area from October 10 to 17, 1944: LENGTH IN INCHES WEIGHT IN POUNDS Minimum: 27.0 Minimum: 1.4 Maximum: 46.7 Maximum: 7.4 Average: 35.7 Average: 3.4 As a result, the mature eel, because of its large size, vigour and abundant, slippery mucus, is not an easy prey for the White Whale. • In the fall, many types of fish congregate in the mouths of a large number of rivers. As the adult eel descends toward the sea, it encounters other fish such as smelt, tomcod and whitefish heading upstream. At this time of the year, the Beluga is not drawn to the river mouths by the seaward run of eel, but rather by these other fish which are easier and more appreciated prey. e - 133 - IS THE BELUGA RESPONSIBLE FOR COD FISHERY FLUCTUATIONS? In our discussions so far, we have attempted to provide as many details as possible on the food found in 107 Beluga taken in the St.Lawrence in 1938 and 1939. According to local whalers, the Beluga feeds on at least five types of important commercial fish. Of these five species, the eel is entirely absent from our samplings and the other four are present to the following extent: 0 SPECIES BELUGA STOMAC HS Number Smelt 1 0.9 Salmon 1 0.9 Herring 2 1.8 Cod 22 20.6 Since cod is the only one of these commercial fish found with any frequency in our samplings, we will limit our discussion to possible relationships between the Beluga and this species. General considerations - In-depth studies carried out in several countries (1) clearly show that the degree of variation in fishery (1) See Tomasevich (1943, pp. 10-17) for a review of basic works on the causes of fishery fluctuations. - 134- yields is variable, changing from year to year. These annual fluctuations must therefore be considered a normal phenomenon, despite the fact that some of the causes remain unexplained. The most important causes include: weather factors (hot or cold summer, with or without storm activity), biological factors (abundant food supply and lack of parasites and enemies, or vice-versa) and economic factors (heavy or light fishing). In general, good fishing years are followed by years of low yield, and vice-versa. Therefore, annual variations in fish supply are the result of true cyclical relationships. • When we apply the term cycle to the life of a fish species such as cod, we mean the duration of the existence of individuals of the same spawning season from the time they hatch until the death of the majority either by natural causes (age, disease and parasites, enemies, etc.) or by artificial means, such as fishing. Under the influence of various factors present in the aquatic environment, young fish of the same spawning season are able to develop to varying degrees and adult populations thus may fluctuate considerably. Fish of the same age make up veritable annual classes, some of which become dominant "bulges" among their kind throughout their life. When the individuals in these particularly abundant annual groups reach commercial size (at least five years old for cod), fishermen have excellent catches (good years). On the other - 135 - hand, catches are poor when the cod that have reached commercial size belong to an underdeveloped or underpopulated "annual class" (bad years). It is extremely important to keep track of an abundant annual group through the years, since the data can help in forecasting future fishing conditions. However, the cycles of different cod generations are not always equal in length: the cycle of good annual groups is usually longer than that of poor groups. As an example, we can point to the cod fishery (G. callarius) • fluctuations along the west coast of Greenland. According to Jensen and Hansen (1931), who have done thorough studies on this fish, cod fishing fluctuations are cyclical in nature. These authors report (1931, pp. 3-9) two periods of abundance during the last century: around 1820 and again around 1845, when "the cod were present in enormous quantities in the Julianehaab district and reached as far north as Disco Bay. Thereafter the cod were absent for a long period of years." In this century, cod were scarce west of Greenland during the 1911-16 period; in 1911, only about 41,000 pounds of this fish were caught. From 1917 to 1930, cod became increasingly plentiful, and t there were enormous catches in the 1925-30 period, as shown in the - 136 - following table ( 1) (Jensen & Hansen, 1931, pp. 7-9): COD C TCH YEAR Kilograms Pounds 1911 18,500 14,785 1916 124,500 274,474 1917 244,000 537,922 1925 957,000 2,109,802 1926 2,055,000 4,530,530 1927 3,291,000 7,255,339 1928 3,680,000 8,112,928 1929 5,634,000 12,420,716 1930 8,160,000 17,989,536 These severe fluctuations in the cod fishery west of Greenland were caused by a number of factors. Jensen and Hansen (1931, p. 30) mention, first of all, years when conditions favoured adult reproduction and survival of the young (good years) and those that were unfavourable (bad years), as follows: BAD YEARS GOOD YEARS i 1911 1912 1914 1917 1915 1922 1918 1924 However, the factors that favoured the exceptionally lucrative fishing in 1925-30 were the changes in hydrological conditions, including an increase in water temperature. According to Jensen & Hansen (1931, p. 40), that temperature rise was due to the following main facts: "The western ice has generally had a more restricted distribution than before; the winters have been unusually mild, etc. Much indicates that the polar current, which, descending from the Arctic, bends round the south point of Greenland and runs further along the south-west coast as a cold stream, has been much less prominent than in earlier years." ♦ (1) Jensen & Hansen (1931, p. 9) give an interesting bar chart illus- trating the gradual increase in annual cod catches from 1911 to 1929 along the western shore of Greenland. We give a condensed form of this information in our table, to which we have added 1930 data ap- pearing separately in the same work by Jensen and Hansen (1931, p. 7). - 137- However, the same authors warn us (1931, P. 40) that these extraordinary conditions, and above all the exceptional cod catches, west of Greenland, are not permanent phenomena. As a result: "one must be prepared ... for a swing back to the earlier condition, which naturally would exercise an influence on the fish stock." It should also be recalled that some factors (such as water temperature) can be at once favourable to some animal species and detrimental to others. Because of such effects, the simultaneous abundance of one species and scarcity of another are often mistakenly interpreted as being interdependent, whereas the two species in • question have no direct interrelationship and are really being separately and inversely affected by the same external factors. The rise in water temperatures to the west of Greenland during the 1925-30 period appears to have been particularly favourable for cod (G. callarias) and a few other temperate species such as haddock and herring. Arctic species such as Beluga, caplin and others, on the other hand, were unfavourably affected. Jensen and Hansen wrote (1931, p. 39) that the Beluga (D. leucas), "which in summer lives far to the north, but in spring wanders southward and passes the winter along the west coast about the Polar Circle, has not appeared in recent years ..., before the middle of - 138 - November at Sukkertoppen and returns northwards again already in January; -- formerly, it arrived at Sukkertoppen in the middle of October and did not migrate away again before April and early May; most recently the White whale has been almost totally absent in winter here to the south, but has been observed on the other hand to have prolonged its stay in the north." These authors noticed (1931, p. 39) a similar change in the behaviour of caplin (M. villosus) during the same period: "(Caplin) earlier in the early summer of each year had swarmed in towards the coastal waters in enormous numbers, from Disco Bay right down to the south point of the land, for spawning purposes, have remained away • from most of their former fishing grounds in the South Greenland waters in recent years." These observations on the conditions that prevailed west of Greenland further illustrate that the requirements of the common cod differ greatly from those of the Beluga. Size of Beluga and cod - Most of the cod caught by the fishermen of these regions weigh over 10 pounds ("round weight"). Our study clearly indicates that the anatomical structure of the Beluga's gullet prevents the whale from swallowing adult cod. Only large male Beluga (1) (1) In the St. Lawrence, adult female Beluga rarely exceed 13 feet in length (Vladykov, 1944, pp. 89-90). - 139- can consume cod which weigh up to about 10 pounds. However, large males make up only a small fraction of the overall Beluga population in the St. Lawrence River. Seasons and centres of concentration - June to October is the high season for cod fishing in Québec. However, our samples have shown that the largest number of Beluga stomachs containing traces of cod were found in August. The St. Lawrence estuary, particularly the mouth of the Saguenay and its vicinity, may be considered a year-round natural habitat for the Beluga. As indicated earlier, many Beluga stay on the Manicouagan Bank in summer. Although the Bank abounds in Nereis, sand launce and other small fish, common cod is scarce. During the fishing season, the main concentrations of cod in our province are located near the Strait of Belle-Isle (Blanc-Sablon region), around the Magdalen Islands and off southern Gaspé (1) and near Baie-des-Chaleurs. In the first two areas, there are no Beluga; in the latter two, a few are found along the shoreline in early spring during the herring and caplin season, but before active cod fishing begins (Vladykov, 1944, pp. 57-61 and 131). (1) Fishermen in this district do most of their cod fishing on the Miscou Banks, 25 miles from Grande Rivière (Labrie, 1943, p. 134). / - 140 - Therefore, season and principal areas of concentration of cod do not coincide with those of the Beluga. To further illustrate this point, figures 41 and 42 give two maps showing the zones of Beluga and cod concentration in our province. Vertical distribution - In summer, the adult cod on the fishing banks are usually concentrated in deep, 10 to 75 fathom waters (Bigelow & Welsh, 1925, p. 414). Beluga, on the other hand, feed in shallow water and probably do not descend beyond 5 fathoms. As a result, the two species must encounter each other rather rarely: Beluga inhabit the upper strata and are separated from cod by a mass • of water several fathoms deep. Cod fishery fluctuations in the St. Lawrence - The variations in the annual yield of cod fisheries are a natural phenomenon totally unrelated to the Beluga. These fluctuations occur not only in the St. Lawrence River and Gulf where Beluga are present, but also in regions not frequented by Beluga, for example, the European coast (North Sea). Since our main area of interest is the St. Lawrence, we shall examine in greater detail cod fluctuations over the past 30 years in this region. Our data on annual cod catches are taken from the fishery statistics published by the Federal Bureau of the Department - 141 - of Trade. In order to assess Beluga populations (1) over the years, we have had to draw mainly on information provided by whalers. The latter source is naturally somewhat imprecise, but is adequate as a general indicator. The parallel between the abundance of Beluga and of cod in the Province of Québec during the same years will show whether or not there is any actual correlation between the two species. As a basis for comparison, we shall take first the years with extreme yields of cod, then the years for which we have personally more data available on the abundance of Beluga, based on our field trips or on detailed • hunter reports: (1) The statistical report on annual Beluga catches in our province is not a sufficient source because in some years, government bounties, etc. (Vladykov, 1944) stimulated the hunt. # - 142 - O Fig. 41.- Usual summer concentration of Beluga in the St. Lawrence River and Gulf (from Vladykov, 1944). tr.* ■t. j • O • - 143 - Fig. 42.- Distribution, by district, of annual common cod catches (Gadus callarias) in the Province of Quebec. The black dots indicate average catches, in pounds, for the 1940-42 three-year period (from Labrie, 1943). FA'W_liO'J . ,. , L E(,EN D i - too,ooo Ibs ^ - 500,000 Ibs a .^oo al0h4f quNçS - 144- YEAR COD CATCH BELUGA POPULATION (pounds) 1918 81,667,500 Usual 1926 58,456,700 Usual 1927] 46,057,300 Much higher than usual 19281- ( 1 ) 46,992,400 Much higher than usual 1929] 49,006,200 Exceptional 1930 39,264,200 Lower than usual 1937 23,986,400 Usual 1938] 31,984,200 Slightly higher than usual 1939] - ( 2 ) 38,764,600 Usual 1943 ( 3 ) 55,204,000 Usual • 1946 ( 4 ) 65,512,400 Usual (1) Over the past 30 years, 1927-28-29 constitute the only period of exceptionally high Beluga concentrations in the St.Lawrence River and Gulf (Vladykov, 1944, pp. 138-142). (2)Years of our Beluga field studies. (3)Year when we visited nearly the entire St. Lawrence River and Gulf region. (4)Year of our summer and fall trips along the south shore of the St. Lawrence River as far as Ile Verte. • -145 - The above table clearly shows that there is no correlaton between annual cod catches and the Beluga population. Indeed, in 1918 when cod catches were the highest of the past 30 years, there were no more or less Beluga than usual. The same number of Beluga was apparently noted in 1937, when the cod catch was the lowest. During the rather poor cod fishing period of 1927-29, Beluga were exceptionally abundant. We are convinced that this abundance was caused by Beluga herds entering the St. Lawrence from outside the region. These newcomers were probably attracted by a drop in water • temperatures. It is important to note that another Arctic species, the caplin, was abundant in the St. Lawrence at the same time, particularly near Rivière-Quelle. This fish, now taken only in small amounts (about 500 pounds per year), near the mouth of the Quelle River, was caught in great numbers from 1927 to 1929. In fact, the operator of one of the local weirs, Luc Bélanger, caught 35,000 to 60,000 lbs of caplin per tide during eight consecutive tides in early May 1929. (1) Similarly, it should be noted that it was in May 1929 that Beluga were taken in very large numbers in a White Whale weir near the Quelle River (Vladykov, 1944, pp. 140-141). There is no doubt (1) The day Luc Bélanger took 60,000 pounds (or 15 loads) of caplin, at least 50 loads (175,000 lbs) remained in his weir. - 146 - the Beluga were attracted by the local abundance of caplin (1). The case of Western Greenland described at the beginning of this chapter clearly shows that fluctuations in cod, caplin and other populations of commercial or non-commercial fish are primarily affected by changes in water temperature and salinity and are unrelated to Beluga populations. Similarly, the geographical distribution and seasonal concentrations of Beluga are affected by hydrological conditions. The conditions prevailing on the west coast of Greenland are • similar to those in the St. Lawrence region. As in Greenland, hydrological variations seem to be of a periodic nature, and can be explained by the theory of Atlantic transgression as defined by Le Danois (1938, pp. 150-170). The cyclical nature of the cod fishery in Quebec can be easily demonstrated by, for example, grouping the catches of the past 30 years in four-year segments: ^ L. Bélanger operated the weir for 45 years, and his son Adalbert was also an experienced fisherman; they stated that the appearance of White Whales near the coast is a sure sign of inshore caplin activity. According to these fishermen, local caplin catches dropped considerably after the 1927-29 period, as did the number of Beluga near the Ouelle River. 0 - 147- PERIOD AVERAGE ANNUAL CATCH (pounds) 1915-18 75,450,000 1919-22 50,100,000 1923-26 50,040,000 1927-30 45,300,000 1931-34 47,900,000 1935-38 34,300,000 1939-42 44,500,000 1943-46 60,480,000 This table clearly illustrates a cycle, beginning with a maximum cod catch in the 1915-18 period (1) and dropping to a minimum in 1935-38. After 1937, the worst year (only 23,186,400 lbs) of the 30-year period, cod catches greatly increased from one period to the next. During the last two years, 1945 and 1946, catches of 65,891,700 111, and 69,512,400 lbs, respectively, almost matched the 1915-18 level. It is very likely that present cod yields will increase for a few more years, regardless of the Beluga population in the St. Lawrence. However, the future also holds the possibility of a new decrease when the fluctuation cycle reaches a peak. Will our fishermen still tend to accuse the White Whale, when the real culprit is the change in hydrological conditions affecting primarily the water temperature and salinity of the St. Lawrence River, and particularly of the Gulf? (f) In 1918, 81,667,500 lbs of cod were caught, which is the maximum for the 30-year period. s ♦ - 148 - CONCLUSIONS The facts established by this study may be summarized as follows: 1.- For the purposes of this study, 165 Belugas were collected in the St. Lawrence River in 1938 and 1939. Of this number, 145 were taken on the Manicouagan Bank, 17 at Les Escoumains and 3 at Rivière-Ouelle. 2.- The stomach of the Beluga is made up of five compartments, the first of which - the esophageal region - is devoid of digestive glands. Because the food in this compartment was less attacked by • digestion, it was this food which was used in our detailed analyses. The esophageal region of an adult Beluga has a capacity of about five gallons. 3.- When a Beluga is frightened, wounded or pursued by a motor launch, it often vomits its food. This is the probable explanation for the fact that the maximum amount of food taken from a single stomach was 19 lbs, and that there was a fairly large number of empty stomachs. 4.- The stomachs collected were in the following condition: 34 empty, 3 containing sand only, 11 containing milk and 117 containing food other than milk. Within the last group, 10 stomachs were • examined in the field and the others (107) in the laboratory. - 149 - 5.- The maximum number of organisms taken from a single stomach bolus was 2,412 caplin (Beluga No. 10), which were counted on the basis of their crystallins. This exceptionally high number was without a doubt the result of the accumulation of crystallins from caplin consumed over several meals. 6.- The largest fish found in a Beluga stomach was a cod measuring about 30 inches and weighing about 10 lbs. A 24-inch sturgeon weighing about two pounds was vomited by another Beluga. 7.- At least 50 species (22 fish, and the balance invertebrate species) were taken from the stomachs of Beluga in the St. Lawrence • River. 8.- Among the fish, the predominant food species were caplin (54 stomachs, i.e. 51%) and sand launce (58 stomachs, i.e. 54%), while among invertebrates, the clam worm or Nereis (64 stomachs, 60%) and squid (35 stomachs, 33%) were predominant. 9.- As a matter of interest, findings included a granite stone weighing 6 lbs 14 oz in one stomach, and red paper used to wrap oranges in two others. 10.- We found a distinct seasonal variation in food composition. In June and July, Beluga of both sexes and all sizes feed almost exclusively on caplin, whereas in August and September, sand launce is O - 150- the principal diet. 11.-There is also a regional variation in food composition, though it is pronounced. On the Manicouagan Bank, Beluga consume large quantities of flounder and Nereis and very few shrimp while at Les Escoumains they eat a great deal of shrimp and very little flounder and Nereis. 12.-There are marked differences in the Beluga diet according to age and sex. Females and young prefer small fish (caplin and launce) and shrimp; whereas adult males supplement their regular diet (caplin • or launce) with large fish such as cod and sculpin. 13.- With only one exception (Beluga No.85), the cod found in the stomachs were in a very advanced state of digestion. As a result, we were not always able to distinguish common cod (Gadus callarias) from Greenland cod (Gadus ogac). We were only able to ascertain the presence of common cod in 22 stomachs (20.6% of the sample). In the other 23 stomachs, we found various fragments (13 stomachs with traces of L. branchialis, 8 with crystallins and 2 with bone fragments) identifying the genus of these fish, but not their species. We have tentatively categorized them as Greenland cod. As a result, in reading the following text it should not be forgotten that many of our cod samples were probably made up of two species, G. callarias and G. ogac. - 151 - 14.- Cod are eaten by large whales, mostly males: only three stomachs of young Beluga contained cod (10/0), as opposed to 21 adult male stomachs (53%). It is important to add that no Beluga stomach contained only cod, to the exclusion of all other foods: other fish or invertebrates were always present. This indicates that, for Beluga - even adult males - cod is not a preferred diet item, but rather a supplement to other, more important foods. 15.- The greatest number of cod found in a single Beluga stomach, as identified by different structural fragments, was 20 by otoliths, 17 by crystallins and 15 by bones. • 16.- The number of stomachs found to contain cod in the 1938 samples varied according to the season: 2(15°0) in June, 8(33°b) in July, 21 (70%) in August and 5(24°6) in September. On the Manicouagan Bank, the greatest number of cod found both in stomachs and in a weir occurred in August (Table XIX). 17.- Although the occurrence of common cod in our food samples may seem high (22 stomachs or 20.00), this does not indicate the true situation. The Manicouagan Bank hunting method favoured the capture of adult males. Also, the greatest number of stomachs were taken in August, a time when cod are abundant in that vicinity. These two factors tend to greatly exaggerate the role of cod in Beluga feeding / habits. - 152 - 18.- As for other fish of commercial value, we found salmon in one stomach only (0.9%), smelt in another (0.9%) and herring in two stomachs (1.8%). Note the absence of eel in our samples. 19.-Although this study confirms that Beluga do consume a limited amount of commercially valuable fish, such as cod, the damage is totally insignificant and has no effect on fishery fluctuations over the years. Destruction by Beluga of a certain number of young cod is amply offset by the whalers' oil and skin sales. (1) • At current prices, an adult Beluga is worth at least $30.00. (1) Further information on the economic value of the Beluga is provided in an earlier publication (Vladykov, 1944, pp. 147-162). - 153 - BIBLIOGRAPHY ARSENYEV, V.A. 1939. Distribution and migration of the White Whale in Far East. Bull. Pac. Sci. Inst. Fish & Ocean. Vol. 15, 1-109 pp. Vladivostok (Russian with English abstract). BABKIN, B.P. 1944. Secretory Mechanism of the Digestive Glands. i-xix, 1-900 pp. New York. BARCLAY & NEILL. 1821. Account of a Beluga or White Whale killed in the Frith of Forth. Mem. Wernerian Nat. His. Soc. Vol. III, pp. 371-394. Edinburgh. BARRINGTON, E.J.W. 1937. The structure and development of the tail in the Place (Pleuronectes platessa) and the Cod (Cadus morrhua). Quart. J. Micros. Sci. Vol.79, N.S., pp. 447-469. BEDDARD, F.E. 1900. A book of Whales. 1-320 pp. London. BELDING, D.L. & G. PREFONTAINE. 1939. Studies on the Atlantic Salmon. III. Report on the Salmon of the 1937 Miramichi (New-Brunswick) drift-net fishery. Contrib. Inst. Zool. Univ. de Montréal. No. 4, 1-63 pp. Montréal. • BIGELOW, H.B. & W.W. WELSH. 1925. Fishes of the Gulf of Maine. Bull. U.S. Bur. Fish. Vol. 40, pp. 1-567. Washington, D.C. BIRULA, A.A. 1934. Ueber die Seesaugetiere des Weissen Meeres. Zool. Anz. Vol. 107, pp. 10-22. Leipzig. BROOKS, H. St. J. 1885. The osteology and anthropology of the Haddock (Gadus aeglefinus). Scien. Proc. R. Dublin Soc. Vol. 4, N.S., pp. 166-196. CALLAMAND, O. (Mademoiselle). 1943. L'Anguille Européenne (Anguilla anguilla L). Les bases physiologiques de sa migration. Ann. Inst. Ocean. Tome XXI, pp. 361-440. Paris. CASGRAIN, abbé. 1873. La pêche aux Marsouins dans le Fleuve Saint-Laurent. 1-16 pp. Montréal. (Published without author's name.) COLLETT, R. 1906. Nogle Meddelelser om Naebhvalen, (Hyperoodon), og Hvidfisken (Delphinapterus). Bergens Museums Aarbog. No. 6, pp. 1-25. Bergen. DMOCHOWSKY, A.W. 1933. Materialien zur Kenntnis der geographischen Verbreitung und Biologie von Delphinapterus in den Weissen Meere. Bull. Soc. Nat. Moscou Sec. Biol. Vol. 42, pp. 85-90. (In e Russian). - 154 - FISET, P.E. 1934. Les Crevettes de l'estuaire du Saint-Laurent Nat. Can. Vol. 61, pp. 111-119. Québec. FREUND, L. 1932. Cetacea. Dans Die Tierwelt der Nord-und Ostsee by Grimpe, G. Part XII, 1-64 pp. Leipzig. GREGORY, W.K. 1933. Fish Skulls: A Study of the Evolution of Natural Mechanisms. Trans. Amer. Philos. Soc. Vol. 23, N.S., pp. i-vii, 1-479. Philadelphia. HEPTNER, W.G. 1930. Materiale zur Kenntnis der geographischen Verbreitung und Biologie des Weisswales (Del hina terus). Arb. Zool. Vorsch. Inst. Vol. 4, part 2, pp. 7-100. In Russian) Moscow. HOLLISTER, GLORIA. 1936. Caudal Skeleton of Bermuda Shallow Water Fishes. I. Order Isospondyli: Elopidae, Megalopidae, Albulidae, Clupeidae, Dussumieriidae, Engraulidae. Zoologica. Vol. 21, pp. 257-290. New York. HOWELL, A.B. 1930. Aquatic Mammals. i-xii, 1-338, pp. Baltimore. KELLOGG, R. 1938. Adaptation of structure to function in Whales. • Cooperation in Research. Carnegie Institution of Washington. Publ. No. 501, pp. 649-682. 1940. Whales, giants of the sea. Natl. Geogr. Mag. Vol. 77, No. I, pp. 35-90. Washington, D.C. JENSEN, A.J. & P.N. HANSEN. 1931. Investigations on the Greenland Cod (Gadus callarias L). Cons. Explor. Mer. Rapp. et Proc.-Verb. Vol. 72, pp. 1-4. Copenhagen. LABRIE, A. 1943. Notre territoire de Pêche Maritime. L'Actualité Econ. Vol. II, No. 2, pp. 105-158. Montreal. LACEPEDE. 1844. Histoire Naturelle. Les Cétacés, les Quadrupèdes ovipares, les Serpents et les Poissons. Nouv. Edit. Vol. I, 1-668 pp. Paris. LAURIE. A.H. 1933. Some aspects of respiration in Blue and Fin Whales, Discovery Reports, Vol. 7, pp. 363-406. Cambridge, England. LE DANOIS, E. 1938. L'Atlantique: Histoire et Vie d'un Océan 1-290 pp. Paris. LYSTER, L.L. 1940. Parasites of some canadian sea Mammals. Can. J. of Research, Vol. 18, pp. 395-409. Ottawa. - 155 - I MORIMOTO, Y., TAKATA, M. & M. SUDZUKI. 1921, Untersuchungen über Cetacea. I. Vorvesuche. Tohoku J. Exper. Medicine. Vol. II, pp. 258-286. Sendai, Japan. PETERS. N. 1937. Ueber Hochseewalfang und Tierleben im Südlichen Eismeer. Der Fischmarkt. No. 7-8, pp. 1-28. Hamburg. PIGEON, J. & A. VALLEE. 1937. Contenu du tube digestif de trois espèces de poissons du Saint-Laurent. Nat. Can. Vol. 64, pp. 33-40. Québec. PRAT, H. 1933. Les zones de végétation et les faciès des rivages de l'estuaire du Saint-Laurent, au voisinage de Trois-Pistoles. Nat. Can. Vol. 60, pp. 93-136, Québec PREFONTAINE, G. 1932. Notes préliminaires sur la faune de l'estuaire du Saint-Laurent dans la région de Trois-Pistoles. Trans. Roy. Soc. Can. III. V'ol. 26, (Sect. V), pp. 205-209. 1933. Additions à la liste des espèces animales de l'estuaire du Saint-Laurent. Ibid. III. Vol. 27, (Sect. V), pp. 253-258. PREFONTAINE, G. & PHILIPPE, L. 1942. Additions à la liste des mollusques de l'estuaire du Saint-Laurent. Ann. A.C.F.A.S. Vol. 8, p. 112. Montreal. RATHBUN, MARY J. 1929. Decapoda. Can. Atl. Fauna. 10. 1-38 pp. Atl. Biol. Station. St-Andrews, N.B. Canada. ROULE, L. 1937. La migration génétique des Anguilles d'Europe (Anguilla anguilla L.). Bull. Inst. Ocean. No. 733, pp. 1-23. Monaco. ROBSON, G.C. 1932. A Monograph of the recent Cephalopoda Part II. The Octopoda. i-xi. 1-359 pp. British Museum (Nat. Hist). London. SCHULTZ, L.P. & A.M. RAFN. 1936. Stomach contents of Fur seals taken off the coast of Washington. J. Mammal. Vol. 17, pp. 13-15. SCOTT, T. & A. SCOTT. 1913. The British parasitic Copepoda. Vol. I, i-x, 1-257 pp. London. STRUTHERS, J. 1896. On the external character of the anatomy of a Beluga (Delphinapterus leucas). J. Anat. & Phys. Norm. & Pathol. Vol. 30, pp. 124-156. London. SUTTON, J.M. & W. J. HAMILTON. 1932. The Mammals of Southampton 0 Island. Mem. Carn. Mus. Vol. 12, Part. 2, pp. 92-93. - 156 - TAKATA, M. 1932. Untersuchungen über Cetacea XI. Ueber die physiologische Bedeutung der abteilungen des Walmagens. Jap. J. Medic. Sci. II Bioch., Vol. I, pp. 11-23. Tokyo. THOMPSON, W. & R. VAN CLEVE. 1936. Life history of the Pacific Halibut. Rep. Int. Fish. Comm. No. 9, pp. 1-184. Seattle, Washington. TOMASEVICH, J. 1943. International Agreements on Conservation of Marine Resources. i-xi, 1-297 pp. Food Research Inst. Stanford University, California. TSCHIRKOWA, A.I. & S. FOLITAREK. 1930. Ueber den Weissval (Delphinapterus leucas Pall.) und dessen Fang in Tschescha Indiga Bai (Barentz-Meer). Arb. & Zool. Vorsch. Inst. Vol. 4, Part 2, pp. 101-128. Moscow (In Russian). VERRILL, A.E. 1882. The Cephalopods of the North-Eastern Coast of America. Trans. Conn. Acad. Arts & Sci. Vol. 5, 1878-1882, pp. 177-446. New Haven. VLADYKOV, V.D. 1933. Biological and Oceanographic Conditions in Hudson Bay. 9. Fishes from the Hudson Bay Region (Except the Coregonidae). Contr. Canad. Biol. Fish. N.S. Vol. 8, No. 2, pp. • 15-61. Toronto. 1936. Capsules d'oeufs de Raies de l'Atlantique canadien appartenant au genre Raja. Nat. Can.. Vol. 63, pp. 211-231. Québec 1940. Nourriture du Marsouin blanc sur les Bancs de Manicouaga. Ann de l'ACFAS. Vol. 6, pp. 120-121. Montreal 1941. The structure of the anal fin in the Caplin, Mallotus, Osmeridae. Nat. Can. Vol. 68, pp. 193-207. Québec. 1944 Études sur les Mammifères aquatiques III. Chasse Biologie et valeur économique du Marsouin blanc ou Béluga (Delphinapterus leucas). 1-194 pp. Département des Pêcheries Maritimes, Québec. 1945. Trois poissons nouveaux pour la Province de Québec. Nat. Can. Vol. 73, Nos 1-2, pp. 27-39. Québec. VLADYKOV, V.D. & J.-L. TREMBLAY. 1935. Liste des poissons recueillis pendant l'été 1934 par la Station Biologique du Saint-Laurent, dans la région de Trois-Pistoles, P.Q. Nat. Can. Vol. 12, pp. 77-82. Québec 1936. Nouvelles espèces de Lycodes (Pisces, Zoarcidae) du Saint-Laurent et revision de toutes les espèces du même genre de l'Atlantique occidental. Fauna et Flora Laurentianae. No 1, 1-45 pp. Québec. WATSON, M. & A.H. YOUNG. 1880. The anatomy of the Northern Beluga (Beluga catodon, Gray: Delphinapterus leucas, Pallas) compared with that of other whales. Trans. Roy. Soc. Edinburgh. Vol. 9, pp. 393-434. - 157 - WHITE, W. HALE. 1891. A theory to explain the evolution of warm-blooded vertebrates. J. Anat. & Phys., vol. 25 (N.S., vol. 5), pp. 374-385. London. WILSON, C.B. 1932. The Copepods of the Woods Hole region, Massachusetts, U.S. Nat. Mus. Bull. No. 158, i-xx, 1-635 pp. Washington, D.C. WYMAN, J. 1863. Description of a "White Fish" or White Whale (Beluga borealis Lesson). J. Nat. Hist. Vol. 7, pp. 603-612. Boston. • O - 158 - APPENDIX The 12 tables that follow, (XXIV to XXXV) contain details of the analysis of 107 Beluga stomachs taken in 1938 and 1939. These tables are divided into two parts. The first part contains information on the Beluga itself: specimen number, length, sex, place and date of capture, whereas the second part refers only to stomach contents. For the sake of clarity, this second part is subdivided into three parts, of which the latter two are self-explanatory, although the first part, entitled Number of organs or parts used to identify Fish, Cephalopods and Nereis, • requires some explanation. In order to identify fish species and count individuals, we used bones, crystallins or otoliths. The number of fish bones stated in the table is equal to the number of specimens. In order to estimate the number of fish on the basis of crystallins or otoliths, the number of crystallins is divided by two, the number of otoliths by six. For caplin and launce, the figures refer only to crystallins, whereas for all other fish they indicate the number of otoliths. For example, in the stomach of Beluga No. 4 (Table XXIV) we found two caplin bones and 216 crystallins from the same species. As a # result, the number of caplin consumed by this Beluga may be - 159 - 2 or 108, depending on whether bones or crystallins are used. In some cases (Table XXV, Beluga No. 124), the number of crystallins (48) is placed between the lines provided for caplin and launce indicating that it was difficult to distinguish the crystallins belonging to each of these species. In such cases, the number of individuals is estimated by dividing the number of crystallins equally between these two species. For invertebrates, the term beak includes the jaws of cephalopods (squid and octopus) and the buccal crotchets of Nereis, and only is crystallins are listed under the heading Crystallins and Otoliths. order to find the number of cephalopods or Nereis, we have taken the figures appearing in the Bones or Beaks column or Crystallins or otoliths column, and divided them by two. Locations indicated in the tables are abbreviated as follows: B.B. -- White Bank (part of the Manicouagan Bank) B.G. -- Clay Bank (part of Manicouagan Bank) B.V. -- Green Bank (part of Manicouagan Bank) L.E. -- Les Escoumains R.M. -- Manicouagan River Estuary ♦ R.Ou. - Near Rivière-Ouelle (Kamouraska). -160- Table XXIV.- Details of Stomach Contents of Young Beluga taken in June and July 1938 on the Manicouagan Bank. rpecimen # 4 10 11 19 24 e Length (in.) 1031 100 94 117 92 Sex e e 0 e Cf Location B.B B.G. B./. B.V. B.V. Date 16.VI . 24.VI 25.VI 30.VI 7.VII 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- or lins or or lins or or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin 2 216 210 4,823 10 197 58 538 137 2,335 Sand launce - - - - - - - - - - Sculpin - - - - 1 - - - - - Tomcod - - - - - - - - - - Flounder - - - - - - - - - - Cod (1) - - - - - - - - - - Salmon - - - - - - - - - - Other fish - - - - 1 (2) - - - - - Squid 4 - - - - - - - - - Octopus - - - - - - _ _ _ _ Nereis 1 - - - - - - - - - Alb 2.- Number of Individuals from Other Groups Polychaetes - - - - - - - - - - Decapods - - - 1 - - - 1 - 1 Amphipods - _ _ _ _ _ _ _ _ _ Other crustaceans - _ _ _ _ _ _ _ _ _ Lamellibranchia - - - - - - - - - - Gastropods - - - - - - - - - 1 Other animals 12 - - 13 - - - 3 - - Plants 1 - - 3 - - - - - 1 3.- Weight of Stomach Contents, in grams Food 533 1,947 670 410 1,458 Sand 4 25 - - 5 (1) In all the tables in the Appendix, the term cod includes the remains of two species: G. callarias and G. ogac. (2)Specimen of hake (Urophycis chuss) - 161 - Table XXIV.- (Continued) Details of Stomach Contents of Young Beluga taken in June and July 1938 on Manicouagan Bank pecimen # 29 31 32 34 47 A VL ength ( in.) 88 87 89 97 111 Sex Location B?V B.V. B. V. B B. B .B. Date 11.VII 13.VII 13.VII 14.VII 27.VII 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- or lins or or lins or or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin 86 6 - 68 87 122 133 119 - - Sand launce ------1 - 4 12 Sculpin - - - - - _ 1 - Tomcod - - - - Flounder - - - - Cod ------1 (3) Salmon - - - - Other fish - - - - Squid - - - - Octopus ------Nereis ------12 - 3 - Ald^ 2.- Number of Individuals from Other Groups Polychaetes Decapods 1 Amphipods 3 Other crustaceans 12 Lamellibranchi 1 4 Gastropods Other animals 2 1 Plants 3 1 1 3.- Weight of Stomach Contents, in grams Food 652 20 1,205 435 94 Sand - - - - 25 This cod was identified by the presence of a copepod parasite, Lernea branchialis. 0 -162 - Table XXV. Details of Stomach Contents of Young Beluga taken in August and September 1938 on Manicouagan Bank .1111■ pecimen # 61 74 98 110 Illrength (in.) 99 103'1 90 105 Sex Location B.B. B.B B.B. B.B. Date I.VIII 9.VIII 30.VIII 2.IX 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- or lins or or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin - - - - - - - - Sand launce 3 648 1 - 54 469 8 121 Sculpin 3 4 1 - - - - - Tomcod - - - - - - - - Flounder - - 1(2) _ _ _ _ - Cod - - 1 - - - - - Salmon - - - - - - - - Other fish 1(1) - - - - - - - Squid 3 - 2 - 9 - - - Octopus - - 2 - - - - - Nereis 57 - 50 - 9 - 131 - 2.- Number of Individuals from Other Groups Polychaetes 3 2 1 - Decapods 2 23 - 1 Amphipods 1 - - - Other - - - - crustaceans Lamellibranchia 2 2 - 1 Gastropods 1 - - - Other animals - - - - Plants 4 - 2 1 3.- Weight of Stomach Contents, in grams Food 1,371 330 1,280 280 Sand 294 100 20 50 (1) One skate egg capsule (Raja?) (2) One specimen of P. americanus. - 163 - Table XXV.- (Continued) Details of Stomach Contents of Young Beluga taken in August and September 1938 on Manicouagan Bank pecimen # 112 113 124 137 146 Illeength (in.) 119 113+ 94 119+ 114+ Sex Location B.B B.B. B.G. B.T. B.G. Date 2.IX 2.IX 9.IX 11.IX 24.IX 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- or lins or or lins or or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin - - - - 8 - - - - Sand launce 101 330 28 91 31 49 8 389 105 668 Sculpin - - - - - - - - - - Tomcod - - - - - - - - - - Flounder 7(3) - 1(4) - - - _ _ _ - Cod - - - - - 12 - - - - Salmon - - - - - - - - - - Other fish - - - - - - - - - - Squid - - 8 - - - 1 - - - Octopus - - - - 1 - - - - - Nereis 5 - 55 - 61 - 59 - - - 2.- Number of Individuals from Other Croups Polychaetes - - - - - Decapods - 1 1 4 - Amphipods - - - - - Other - - - - - crustaceans Lamellibranchia - 1 - - - Gastropods _ _ - - _ Other animals - - - - - Plants 1 1 2 3 3 3.- Weight of Stomach Contents, in grams Food 1,220 400 515 685 2,320 Sand - 250 10 3 40 (3) Three specimens of P. amerIcanus and four of L. putnami (4)One specimen of L. putnami. - 164 - Table XXVI. Details of Stomach Contents of Female Beluga taken in July 1938 on Manicouagan Bank pecimen # 25 30 35 37 Illrength (in.) 135 136 143 138 Location B.V. B.V B.V. B.G. Date 7.VII 11.VII 14.VII 14.VII 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- or lins or or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin 198 3,004 168 389 190 294 4 - Sand launce - - - - - - - - Sculpin - - - - 1 - - - Tomcod - - - - - - - - Flounder - - - - - - - - Cod - - - - - 1(1) _ _ Salmon - - - - - - - - Other fish - - - - - - - - Squid - - - - - - - - Octopus - - - - - - - - Nereis - - - - - - - - 2.- Number of Individuals from Other Groups MI Polychaetes - - - - Decapods - 1 1 - Amphipods - 2 - - Other crustaceans - - - - Lamellibranchia - - - - Gastropods - - - - Other animals - - 1 - Plants - 7 3 1 3.- Weight of Stomach Contents, in grams Food 2,125 2,083 1,555 50 Sand 10 30 - - _i_ (1) This cod was identified by the presence of the copepod parasite, Lernea branchialis - 165 - Table XXVI. (Continued) Details of Stomach Contents of Female Beluga taken in July 1938 on Manicouagan Bank pecimen 44 48 49 50 Length (in.) 136 133 124 144 Location B. V. B. B. B. B. B. B. Date 20.VII 27.VII 28.VII 28.VII 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- or lins or or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin 2 ------Sand launce 10 491 3 26 4 11 4 24 Sculpin ------Tomcod - - - - 1 - - - Flounder ------Cod - 1 ------Salmon ------Other fish ------Squid ------Octopus ------Nereis 19 - 33 - 4 - 15 - 2.- Number of Individuals from Other Groups tolychaetes 1 Decapods 5 1 2 1 Amphipods 3 Other crustaceans - Lamellibranchi 1 Gastropods - Other animals 1 1 Plants 1 7 1 3.- Weight of Stomach Contents, in grams Food 420 178 67 135 Sand 25 5 25 10 ♦ -166- Table XXVII. Details of Stomach Contents of Female Beluga taken in August 1938 on Manicouagan Bank pecimen # 58 60 62 70 71 Ilren gth (in.) 132 139 143 161 122 Location B.B. B.B. - B.G. B.B. Date I.VIII I.VIII I.VIII 4.VIII 7.VII 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- or lins or or lins or or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin - - 41 - - 10 1 - Sand launce 1 13 2 159 4 8 49 433 1 - Sculpin - - - - - - 1 2 - Tomcod - 18 - - - - - - - - Flounder - - - - - - - - 1(3) - Cod - - - 1(1) - 1 1 - 2 - Salmon - - - - - - - - - - Other fish - - - - - - 2(2) - - - Squid 2 - 7 - - - 6 - 2 - Octopus - - 1 - - - 1 - 3 - Nereis 12 - 15 - 43 - 2,222 - 3 - 2.- Number of Individuals from Other Groups NMI Polychaetes 7 7 2 2 1 Decapods 4 1 - 3 1 Amphipods 12 - - - - Other - - - - - crustaceans Lamellibranchia - 1 2 19 3 Gastropods 1 - - - - Other animals - - 1 3 1 Plants 1 3 - 3 3 3.- Weight of Stomach Contents, in grams Food 18 748 205 2,645 730 Sand 25 5 40 2,315 10 (1)This cod was identified by the presence of Lernea branchialis. (2)One skate egg capsule (Raja ?) and Lamprey teeth (Petromyzon?). (3)One specimen of P. americanus. di - 167- Table XXVII (continued) Details of Stomach C ntents of Female Béluga taken in August 1938 on Manico agan Bank iiecimen # 72 75 93 99 108 108 111Pength (in.) 130 - 130 126 131 131 Location B.B. B.B. B.B. B.B. B.B. B.B. Date 7.VIII 9.VIII 25.VIII 30.VIII 31 .VIII 31 .VIII 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- or lins or or lins or or lins or or lins or or lins or Bones Crystal- beaks otoliths beaks otoliths beaks otoliths beaks otoliths beaks otoliths iàr lins or beaks otoliths ,,- Caplin - - - - - - - - - - Sand launce 2 - - - 4 - 8 164 30 455 Sculpin 1 - - - - - - - 1 - Tomcod - - - - - - 10 9 - - Flounder - - - - - - 1(4) - - - Cod - - 1(5) - - - - - 1 - Salmon - - - - - - - - - - Other fish - - - - - - 9 164(6) - - Squid - - - - 197 153 1 - 15 - Octopus.._ - - - - - - 1 1 - - Nereis - - - - - - 13 - 2,732 - 2.- Number of Individuals from Other Groups 91Folychaetes - - - - 9 Decapods 1 1 - 6 6 Amphipods 1 - - - - Other crustaceans - - - - - Lamellibranchia - - - 1 6 - GastroPods - - - - - . Other animals - - - - 1 Plants - 1 - 1 3 , 3.- Weight of Stomach Contents, in grams Food 20 6 95 1,475 2,190 1,140 Sand - 1 10 5 1,650 20 (4) One specimen of P. americanus (5) This cod was identified by a vertebra. (6) Several specimens of smelt (Osmerus mordax): at least 9 individuals were counted by meanS of skeletal remains, and 164 crystallins obviously belonged to the same species. 168 Table XXVIII. Details of Stomach Contents of Female Beluga taken in September 1938 on Manicouagan Bank pecimen # 111 121 127 128 132 ength (in.) 151 149 137 128 131 Location B.B. R.O. B.G. B.B. B.V. Date 2.IX 8.IX 9.IX 1O.IX 1O.IX 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- or lins or or lins or or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin 1 ------Sand launce 40 565 11 208 68 338 7 144 4 202 Sculpin 1 - - - 1(5) - - - - - Tomcod ------Flounder 2(1) - - - 1(6) - - - 1(7) - Cod - 4 - 1(3) - 6 - - - - Salmon ------Other fish 1(2) - 1(4) ------Squid 22 - 251 - 13 - 2 - 1 - Octopus 23 - 24 ------Nereis 2,469 - 1,255 - 1,366 - 2 - 3 - 2.- Number of Individuals from Other Groups t olychaetes 23 2 8 2 ecapods 16 5 1 Amphipods 3 Other crustaceans Lamellibranchi 14 5 2 1 Gastropods 2 1 Other animals 1 Plants 4 3 3 3.- Weight of Stomach Contents, in grams Food 1,370 470 1,730 110 185 Sand 2,140 1,100 1,050 50 60 (1) One specimen of P. americanus and one L. putnami (2) Lamprey teeth (Petromyzon? (3) This cod was identified by the presence of Lernea branchialis (4) One skate egg capsule (Raja senta) (5) One specimen of Gymnocanthus tricuspis (6) One specimen of L. putnami (7) One specimen of L. putnami 0 - 169 - Table XXVIII. (Continued) Details of Stomach Contents of Female Beluga taken in September 1938 on Manicouagan Bank pecimen # 135 138 140 143 145 Pength (in.) 142 130 141-1 121 125 Location B.G. B.G. B.G. B.B. B.B. Date 11.IX 12.IX 23.IX 23.IX 24.IX 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- Or lins or or lins or or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin - - - - - - - - - - Sand launce 283 1,012 149 244 323 1,175 48 543 185 883 Sculpin - - 1 - - - - - - - Tomcod - - - 3 2 162 1 29 - 17 Flounder - - - _- - - - - - - Cod - - - - - - - - - Salmon - - - - - - - - - - Other fish - - - - - - - - - - Squid - - - - - - 1 - - - Octopus - - - - - - - _ _ _ Nereis 1 - 30 - 27 - 40 - 16 - 2.- Number of Individuals from Other Croups lychaetes - - - - - tcapods - 7 13 1 1 Amphipods - 37 51 39 2 Other crustaceans - - - - - Lamellibranchi 1 - - - 1 Gastropods - - - - - Other animals - - - - - Plants 3 1 1 3 2 3.- Weight of Stomach Contents, in grams _ Food 4,530 1,488 2,870 1,390 1,725 Sand 5 20 15 100 15 • - 170 - Table XXIX. Details of Stomach Contents of Male Beluga taken in June 1938 on Manicouagan Bank pecimen # 1 2 3 6 Length (in.) 1492 148 161 151 Location B.V. B.B. B.B. B.B. Date 1O.VI 15.VI 15.VI 16.VI 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- or lins or or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin 20 - 177 - 204 - - 60 Sand launce ------Sculpin 3 - - - 1 - - - Tomcod ------1 - Flounder ------Cod ------1(1) - Salmon ------Other fish ------Squid ------Octopus ------Nereis ------ 2.- Number of Individuals from Other Groups olychaetes Decapods 2 Amphipods Other crustaceans Lamellibranchi 1 Gastropods I - 1 Other animals - Plants 1 3.- Weight of Stomach Contents, in grams Food 186 3,430 3,600 19 Sand 100 - - 8 (1) This cod was identified by a tooth. ♦ - 171 - Table XXIX.(Continued) Details of Stomach Contents of Male Beluga taken in July 1938 on Manicouagan Bank. pecimen # 8 9 12 14 18 h (in.) 158 163 150 137 169 lengtLocation B.V. B.V. B.V. R.M. B.V. Date 24.VI 24.VI 27.VI 28.VI 30.VI 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- or lins or or lins or or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin 40 - 296 1,797 15 - - 22 61 31 Sand launce - - - - 14 437 - - - - Sculpin - - - - - - 1 - - - Tomcod - - - - - - - - - - Flounder - - - - - - - - - - Cod - - - - 6 9 - - - - Salmon - - - - - - - - - - Other fish - - - - - - - - - - Squid - - - - 13 - - - - - Octopus - - - - - - - - - - Nereis - - - - - - - - - - 2.- Number of Individuals from Other Groups Wolychaetes - - - - - Decapods - - - - 1 Amphipods - - - - - Other crustaceans - - - - - Lamellibranchia - - 1 - - Gastropods - - 1 - - Other animals - - - - - Plants - 1 - - 1 3.- Weight of Stomach Contents, in grams Food 1,590 2,040 492 139 720 Sand 10 20 25 3 - • - 172 - I Table XXX. Details of Stomach Contents of Male Beluga taken in June 1938 on Manicouagan Bank. pecimen # 20 21 26 27 33 ength (in.) 148 1232 161 161 149 Location B.V. B.V. B.V. B.V. B.B. Date I.VII I.VII 7.VII 8.VII 13.VII 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- or lins or or lins or or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin 48 41 19 482 179 701 384 20 102 125 Sand launce ------Sculpin ------Tomcod - - - - 1 - - - - - Flounder ------Cod ------1 - - 1 Salmon ------Other fish ------Squid ------Octopus ------Nereis ------1 - 2.- Number of Individuals from Other Groups olychaetes Decapods 1 Amphipods 2 Other crustaceans Lamellibranchi Gastropods Other animals Plants 2 2 3.- Weight of Stomach Contents, in grams Food 1,950 358 2,070 3,000 1,477 Sand - 2 10 - - 0 - 173 - Table XXX.(Continued) Details of Stomach Contents of Male Beluga taken in June 1938 on Manicouagan Bank. fipecimen # 36 38 42 46 52 Eength (in.) 122 164 139 170 168 Location B.V. B.G. B.V. B.G. B.V. Date 14.VII 18.VII 20.VII 20.VII 27.VII -- 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- or lins or or lins or or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin 32 20 53 798 - - - - - - Sand launce - - - - 1 4 1 179 13 268 Sculpin - - - - 4 - - - 1 - Tomcod - - - - 1 - 1 - 1 - Flounder - - - - - - - 4 - - Cod - - - - - 1 - - 3 5 Salmon - - - - - - - - - - Other fish - - - - - - - - 1(1) _ Squid - - 3 - - - 7 - 6 7 Octopus - - - - - - 17 - 9 - Nereis - - 23 - 2 - 29 - 25 - 2.- Number of Individuals from Other Groups plychaetes - - - - - p ecapods - 1 - 19 13 Amphipods - - 1 1 10 Other crustaceans - - - - - Lamellibranchia - - - - 2 Gastropods I - - - - 1 Other animals - 2 - - - Plants - 7 - 3 10 3.- Weight of Stomach Contents, in grams Food 320 395 374 250 308 Sand 20 5 - 100 30 (1) Cluster of Neoliparis atlanticus eggs. - 174 - Table XXXI.- Details of Stomach Contents of Male Beluga taken in August 1938 on Manicouagan Bank. pecimen # 55 63 65 66 67 h (in.) 165 136 163 160 160 PengtLocation B.V. B.B. B.B. B.B. B.V. Date I.VIII I.VIII 3.VIII 3.VIII 3.VIII 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- Or lins or or lins or or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin - - - - 1 1 12 2 132 Sand launce 2 41 5 13 1 270 - - - - Sculpin 1 - 1 - - 1 1 - 5 - Tomcod - - - - - - - - - - Flounder - - - - - - - - - - Cod - 1 1 - 9 120 - 1(3) 10 73 Salmon - - - - - - - - - - Other fish 1(1) - - - 1(2) - - - - - Squid - - - - - - 4 - - - Octopus - - - - - - 1 - - - Nereis - - 15 - 8 - 2 - 2 - 2.- Number of Individuals from Other Groups 11Polychaetes 1 - 8 - 2 Decapods 5 1 3 2 4 Amphipods - - 65 10 3 Other crustaceans - 1 - - - Lamellibranchi 2 1 3 - 2 Gastropods 1 - 2 1 2 Other animals 1 - 3 - 1 Plants 2 - 1 1 3 3.- Weight of Stomach Contents, in grams Food 57 200 800 45 1,490 Sand 3 - 20 40 20 (1) Cluster of Neoliparis atlanticus eggs. (2)One haddock (3)This cod was identified by the presence of Lernea branchialis - 175 - Table XXXI.- (Continued) Details of Stomach Contents of Male Beluga taken in August 1938 on Manicouagan Bank. pecimen # 69 76 83 85 89 Length (in.) 169 167 169 164 - 1 Location B.V. B.B. B.G. B.V. - Date 3.VIII 9.VIII 19.VIII 19.VIII 20.VIII 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- or lins or or lins or or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin ------Sand launce - 316 - 2 1 - - - - - Sculpin 3 ------2(9) - Tomcod ------Flounder ------1(6) 1 - - Cod 8 104 - 14 3 2 5 - - - Salmon ------Other fish 1(4) - - - 1(5) - 1(7) - 5(10) - Squid 1 7 2 1 - 2 - 3 1 - Octopus ------4 - Nereis 4 - 3 ------ 2.- Number of Individuals from Other Groups 0olychaetes 10 Decapods 3 10 5 4 1 Amphipods 1 1 Other crustaceans Lamellibranchi a 2 Gastropods 3 1 Other animals 2 1 Plants 3 1 3.- Weight of Stomach Contents, in grams Food 855 48 1,090 5,265 95 Sand 40 - - 3,210(8) - (4) Cluster of N. atlanticus eggs. (5) Cluster of N. americanus. (6) One specimen of P. americanus. (7) One specimen of herring (Clupea harengus). (8) One granite stone (9) Two specimens of G mnocanthus tricuspis (10) Five skate egg capsules (Raja radiata) ♦ - 176 - Table XXXI.- (Continued) Details of Stomach Contents of Male Beluga taken in August 1938 on Manicouagan Bank. pecimen # 91 92 94 96 107 ength (in.) 169 130 176 168 172 Location B.B. B.B. B.V. B.V. B.G. Date 23.VIII 23.VIII 27.VIII 27.VIII 31.VIII 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- or lins or or lins or or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin ------Sand launce - - - - 4 - - - 8 232 Sculpin - 9 - 20 1 - - - - - Tomcod ------Flounder - - - - (13) - - - - - Cod - 7 - - 7 15 1 3 - - Salmon ------Other fish (11) - (12) - - - (14) - - - Squid 164 105 89 - 40 - - - - - Octopus ------Nereis 3 - 2 - - - - - 60 - 2.- Number of Individuals from Other Groups olychaetes Decapods 2 1 2 1 Amphipods Other crustaceans Lamellibranchi 1 1 Gastropods Other animals 1 Plants 1 1 1 3.- Weight of Stomach Contents, in grams Food 1,490 680 362 102 640 Sand - - 10 - 20 (11) One skate egg capsule (Ra'a?) (12) Two skate egg capsules Raja senta) (13) One specimen of P. americanus (14) One sturgeon (Acipenser oxyrhynchus) 24 inches long. 0 - 177 - Table XXXII.- Details of Stomach Contents of Male Beluga taken in August and September 1938 on Manicouagan Bank. , ecimen # 108a 126 133 136 139 141 ength (in.) - 148 170 176 129 122 rLocation - B.G. B.V. B.G. R.M. B.G. Date VIII 9.IX 10.IX 11.IX 16.IX 23.IX 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal ffl3ones Crystal- Or lins or or lins or or lins or or lins or or lins or 1 or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin - 241 - - - - - - - - Sand launce - 478 - 14 71 103 333 26 63 244 162 Sculpin - - - - - - - - - ,1- Tomcod - - - - - - - - Flounder 1(1) - - - - - - - 1(3) - Cod 15 72 - - - - - 1 - Salmon - - _ _ _ _ - _ - Other fish 2(2) - - - - - - - - Squid - - - - - - 2 - Octopus - - - - - - - - - Nereis 2 - - - - - - 8 2.- Number of Individuals from Other Croups lychaetes 9 - - - - kcapods 2 - - 1 1 Amphipods 53 - - - - Other crustaceans - - - - -, Lamellibranchia 2 1 1 1 - Gastropods 1 - 1 - - Other animals 2 - - - - Plants 4 - 1 - 2 i 3.- Weight of Stomach Contents, in grams Food 1,080 4,500 370 1,265 315 2,125 Sand 50 - 5 30 15 30 (1) One specimen of P. americanus (2) Two specimens of haddock (3)One specimen of P. americanus - 178 - Table XXXIII.- Details of Stomach Contents of Male Beluga taken in June 1939 at Les Escoumains. pecimen # 301 303 304 P ength (inch) 78.- 139 159 Sex C? e CP Date 21.VI 25.VI 26.VI 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths Caplin 81 479 18 - 64 235 Sand launce - - - - - - Sculpin - - 1 - - - Tomcod - - 1 - 1 - Flounder - - - - - - Cod - - - 1(2) - 1(2) Salmon - - - - 1 - Other fish - - - - 2(3) - Squid - - - - - - Octopus - - 4 1 2 2 Nereis - - 10 - 7 - 2.- Number of Individuals from Other Groups •lychaetes 1.M 4 Decapods ■■•■I 32 54 Amphipods 8 187 Other crustaceans 1 ■•• Lamellibranchia 6 Gastropods ••••• 1 Other animals 1 Plants 2 ••■■ 3 3.- Weight of Stomach Contents, in grams Food 599(1) - 4,316 Sand - - 20 (1) The stomach bolus of Beluga No.301 was not kept in its entirety and this weight represents only about 1/20 of the full contents. (2) Cod were identified in the stomachs of Beluga Nos. 300, 303-305 by the presence of Lernea branchialis. (3)One specimen of sturgeciii- (TCIpenser) and one of henfish (Cyclopterus lumpus). - 179 - Table XXXIII.- (Continued) Details of Stomach Contents of Beluga taken in June 1939 at Les Escoumains. ›pecimen # 300 305 306 307 Length (in.) 132.1-. 123 136 144 Sex Q Date 21.VI 28:VI 30.VI 30.VI 1 - Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- Or lins or or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin 76 658 107 1,403 27 534 316 1,932 Sand launce - - - - - - - - Sculpin - 6 - - 1 - - - Tomcod - 1 - - - - - - Flounder - - - - 1(4) - _ - Cod - 1(2) - 1(2) - 2 - - Salmon - - - - - - - - Other fish _ - _ - 6(5) - - _ Squid - - - - - - - - Octopus - - - - - 2 - - Nereis 5 - - - 21 - 4 - 2.- Number of Individuals from Other Groups 11Polychaetes - - - - Decapods 2 - 57 - Amphipods - 3 - 2 Other crustaceans 8 - - - Lamellibranchia - - - - Gastropods - - 1 - Other animals - - - - Plants - 1 4 5 3.- Weight of Stomach Contents, in grams Food 660 2,035 1,506 2,599 Sand 2 5 15 10 (4) One specimen of Glyptocephalus cynoglossus. (5)Five specimens of eelpout (Zoarces anguillaris) and one blenny. - 180 - Table XXXIV. Details of Stomach Contents of Beluga taken in July 1939 at Les Escoumains pècimen # 310 313 308 ength (in.) 100 922 138 JfSex e e Date 13.VII 24.VII 4. VII 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- or lins or or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin 80 50 402 10 148 79 Sand launce 1 1,621 - - - - 3 952 Sculpin - - - - 2 - - - Tomcod ------1 - Flounder ------Cod - 1(1) - - - 1(1) - - Salmon ------Other fish ------Squid ------Octopus 1 - - - 8 - 1 - Nereis 19 - 4 - 12 - 13 - 2.- Number of Individuals from Other Groups ^lychaetes 1 2 Wecapods 5 5 197 2 Amphipods 8 1 6 54 Other crustaceans Lamellibranchi 1 Gastropods Other animals Plants 1 1 3 3.- Weight of Stomach Contents, in grams Food 945 463 925 953 Sand 5 2 10 10 (1) Cod in the stomachs of Beluga Nos. 309, 310, 314 and 315 were identified by the presence of Lernea branchialis. - 181 - Table XXXIV. (Continued) Details of Stomach Contents of Beluga taken in July 1939 at Les Escoumains pecimen # 399 311 312 • 314 (in.) Length 111 131 134 131 Sex Date 8.VII 15.VII 22.VII 24. VII 1.- Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- Or lins or or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin 7 486 114 144 16 34 119 Sand launce - - - - 2 46 - - Sculpin - - - - - - - - Tomcod - - - - - - - - Flounder - - - - - - - - Cod - 1(1) - - - - - 1(1) Salmon - - - - - - - - Other fish - - - - 1(2) _ - - Squid - - - - - - - - Octopus 1 - - - 1 - 2 - Nereis 3 - 2 - - - 11 - 2.- Number of Individuals from Other Groups olychaetes - - - - Decapods 113 - 1 - Amphipods 12 2 7 2 Other crustàceans - - _ - Lamellibranchia - - - - Gastropods - - - - Other animals - - - - Plants 1 - 1 ' 3 3.- Weight of Stomach Contents, in grams Food 1,121 1,216 312 157 Sand 10 5 - 3 (2) One specimen of eelput (Zoarces anguillaris). - 182 - Table XXXV.- Details of Stomach Contents of Beluga taken in August and November 1979 in the St Lawrence River pecimen # 316 318 332 333 Pength (in.) 135 147 140 129.1 Sex 9. e Site L.E. B.B. R. Ou. R. Ou. Date 2.VIII , 27.VIII 7.XI 3.XI 1 - Numbers of Organs or Parts used to identify Fish, Cephalopods and Nereis Bones Crystal- Bones Crystal- Bones Crystal- Bones Crystal- Or lins or or lins or or lins or or lins or beaks otoliths beaks otoliths beaks otoliths beaks otoliths Caplin 5 - - - - - - - Sand launce 1 - 42 46 - - - - Sculpin 1 - - - - 1 - 29 Tomcod - - - - - 88 13 198 Flounder - - - - - - - - Cod (1) - - - - - - - - Salmon - - - - - - - - Other fish 28(1) - - - - - - - Squid - - - - - - - - Octopus - - - - - - - - Nereis 6 - - - 15 - 50 - 2.- Number of Individuals from Other Groups gur Polychaetes - - - - Decapods 3 - 8 - Amphipods 8 2 10 9 Other crustaceans - - - - Lamellibranchia - - - 2 Gastropods - - - - Other animals - - - - Plants 3 - - - 3.- Weight of Stomach Contents, in grams Food 639 257 - - Sand 1 300 - - (1) One sturgeon (Acipenser) and 27 herring (Clupea harengus) -183 - PUBLICATIONS OF THE DEPARTMENT OF FISHERIES AND RESEARCH SUBSIDIZED BY THIS DEPARTMENT No.1.- Les Pêcheries de la Province de Québec. 1br partie. (Introduction Historique.)..By E.T.D. Chambers. 214 pages, 55 figures, 1912 (Out of print). No.2.- Quebec Fish for Fur Bearing Animals. By Louis Bérubé. 24 pages, 9 figures, 1937. No.3.- Études sur le Saumon de l'Atlantique (Salmo salar L.) I. Organisation et résultats généraux des recherches dans le golfe Saint-Laurent en 1927. Oy David L. Belding et Georges Préfontaine. 48 pages, 13 figures, 1938. No.4.- Studies on the Atlantic Salmon. IL Report on the Salmon of the 1937 Port-aux-Basques (Newfoundland) Drift-Net Fishery. By David L. Belding and Georges Préfontaine. 58 pages, 4 figures, 21 tables, 1938. No.5.- Studies on the Atlantic Salmon. III. Report on the Salmon of the 1937 Miramichi (New Brunswick) Drift-Net Fishery. By David L. Belding and Georges Préfontaine. 63 pages, 4 figures, 31 tables, 1939. No.6.- Études sur les Mammifères Aquatiques. I. La peau du Marsouin blanc ou Béluga (Delphinapterus leucas). Par W. Bonin et Vadim-D. Vladykov. (Extract from Naturaliste Canadien, Vol. 68, Nos 10 and 11, pp. 253-287, 1940). 35 pages, 18 figures, 1940. No.7.- Department of Fisheries Annual Report for the calendar year 1940. 32 pages, 1941. No.8.- The Structure of the Anal Fin in the Caplin, Mallotus, - Osmeridae. By Vadim.-D. Valdykov (Excerpt from Naturaliste Canadien, Vol. 68, Nos. 8 and 9, pp. 183-207, 1941). 25 pages, 3 figures, 1941. No.9.- Department of Fisheries Annual Report for the calendar year 1941. 55 pages, 1942. No.10.- Studies on Aquatic Mammals. II. A modification of the pectorals fins in the Beluga from the St.Lawrence River. By Vadim-D. Vladykov (Excerpt from Naturaliste Canadien, s Vol. 70, Nos 1 and 2, pp. 23-40, 1943). 18 pages, 7 figures, 1943. No.11.- Department of Fisheries Annual Report for the calendar year 1942. 77 pages, 1943. DATE DUE DATE DE RETOUR c> I LONG-MARTIN No. 1137 -184- ,PUBLICATIONS OF THE DEPARTMENT OF FISHERIES AND RESEARCH SUBSIDIZED BY THIS DEPARTMENT No.12.- Relation Between Fish and Fish-eating Birds. By Vadim-D. Vladykov (Excerpt from Canadian Field-Naturalist, Vol.57, Nos 7 and 8, pp. 124-132, 1943). 9 pages, 1943. No.13.- Department of Fisheries Annual Report for the calendar year 1943. 118 pages, 1944. No.14.- nudes sur les Mammifères aquatiques. III. Chasse, biologie et valeur économique du Marsouin blanc ou Béluga (Delphinapterus leucas) du fleuve et du golfe Saint-Laurent. By Vadim-D. Vladykov. 194 pages, 57 figures, 28 tables, 4 map inserts, 1944. No.15.- Trois Poissons Nouveaux pour la Province de Québec. By Vadim-D Vladykov (Excerpt from Naturaliste Canadien, Vol. 73, Nos 1 and 2, pp. 27-39, 1945). 13 pages, 5 figures, 1945. No.16.- Department of Fisheries Annual Report for calendar year 1944. 97 pages, 15 figures, 1945.