Title Notes on Feeding Habits of the Mesopelagic Fish Maurolicus japonicus off the Pacific Coast of Northern Japan

Author(s) UCHIKAWA, Kazuhisa; KITAGAWA, Daiji; SAKURAI, Yasunori

Citation 北海道大学水産科学研究彙報, 52(3), 151-156

Issue Date 2001-12

Doc URL http://hdl.handle.net/2115/21957

Type bulletin (article)

File Information 52(3)_P151-156.pdf

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Hokkaido University Collection of Scholarly and Academic Papers : HUSCAP Bull. Fac. Fish. Hokkaido Univ. 52(3), 151-156, 2001.

Notes on Feeding Habits of the Mesopelagic Fish Maurolicus japonicus off the Pacific Coast of Northern Japan

2 Kazuhisa UCHlKAWAI), Daiji KITAGAWA ) and Yasunori SAKURAl!)

Abstract

The diet of Maurolicus japonicus, one of the most numerically abundant mesopelagic fish in the adjacent waters of Japan, was examined based on a total of 112 specimens collected off the Pacific coast of northern Japan during October, 1996. The prey was comprised of mainly crustaceans; copepods and euphausiids. For small-sized fish « 40 mm in standard length: SL), the copepods (mainly Calanus pacificus) was the most important prey accounting for 80.9% by number and 44.3% by wet weight. For large fish (~40 mm SL), euphausiids (mainly Euphausia pacifica) was the most important prey representing 40.3% by number and 80.6% by wet weight of the total diet. The prey size differed significantly with fish size, showing that the diet of M. japonicus shifts toward larger prey with fish growth. Feeding intensity measured as stomach content index increased steadily from morning (6: 00 h) through afternoon (14: 49 h) suggesting continuous feeding throughout the daytime. The importance of C. pacificus and E. pacifica in the diet was ascribed to its co-occurrence with M. japonicus throughout the day as a result of diurnal migration both by predator and prey.

Key words: Maurolicus japonicus, Sternoptychids, Mesopelagic fish, Euphausia pacifica, Calanus pacificus, Feeding habit, Diet

Introduction study reports on the feeding habits of M japonicus off the Pacific coast of northern Japan. The sternoptychid fish genus Maurolicus is abundant­ ly distributed over upper continental slopes and subma­ Materials and Methods rine rises in the world oceans (Parin and Kobyliansky, 1996). According to the recent revision made by Parin Samples were collected during the demersal fish sur­ and Kobyliansky (1993), the genus Maurolicus is veys conducted by the Tohoku National Fisheries divided into 15 allopatric species, and M japonicus is Research Institute in October, 1996. During the cruise, distributed around the Japanese archipelago. In the a bottom trawl net with a mouth opening of 3.3 X 18.2 m Japan Sea, M japonicus is the primary food of many was towed at an average ship speed of 3 knots (5.7 km· marine top-predators, e.g. walleye pollock Teragra h-!). The net was lined with 8 mm mesh, and was chalcogramma and the Japanese common squid Todar­ towed for 30 minutes at fishing depth at each sampling odes paciftcus (Okiyama, 1971). Off the Pacific coast of station. All of the samples used in the present study northern Japan, the dominant demersal fish, Pacific cod were taken during the daytime (from about one hour Gadus macrocephalus and walleye pollock T. chalcer after sunrise to two hour before sunset). Maurolicus gramma, also consume M japonicus (Yamamura and japonicus was collected at 10 out of 61 stations with Inada, 2(01). Thus M japonicus play an important bottom depths of 170 to 610 m. role in transferring organic material through the trophic Fish samples were fixed in a 10% buffered formalde­ levels in both the Japan Sea and Pacific Ocean. hyde seawater solution at sea and then transferred to 50% There have been many studies on the ecology of M isopropyl alcohol in the laboratory. Samples were japonicus conducted in the Japan Sea; life history measured and weighed to the nearest 0.1 mm standard (Okiyama, 1971 ; Yuuki, 1982, 1984; Ikeda, 1994), feed­ length (SL) and 0.1 g, respectively. Stomach contents ing habits (Ikeda et al., 1994) and energy budget (Ikeda, were then examined based on a total of 112 specimens 1996). On the contrary, no information has been avail­ collected at five stations (Table 1). Prey were identified able on its ecology along the Pacific coast. The present to the lowest taxon possible, counted and weighed to the

1) Laboratory of Marine Ecology, Graduate School of Fisheries Sciences, Hokkaido University (~twiJtk"F:k"F~*N.f4"F1Uf~f4Ji~~N.~~~mD 2) Tohoku National Fisheries Research Institute (*N.~ft1Uf~~ / ~ - *~t IR*N.~PJT)

~151~ Bull. Fac. Fish. Hokkaido Univ. 52(3), 2001.

Table I Sampling data of bottom trawls conducted off the Pacific coast of northern Japan during the cruise of RV Wakataka-Maru in October, 1996.

Sampling locality Trawling Bottom No. of specimens Date Latitude (N) Longitude (E) mid-time depth (m) examined

7 Oct 38°57 141°02 14: 49 257 7 9 Oct 38°32 14n4 09: 05 252 38 16 Oct 3T59 141°42 06: 40 172 21 19 Oct 3TOI 14n8 08: 39 251 29 21 Oct 36°34 141°03 II: 58 248 17

Total 112 nearest 0.1 mg. Prey found in the mouth cavities and 200 esophagi were excluded from the analyses since they N=832 were probably ingested in the net. There was no sign of ..s= 150 regurgitation and stomach eversion. The stomach con­

-152- UCHIKAWA et al.: Feeding habits of Maurolicus japonicus

Table 2. Diet of two size classes of Maurolicus japonicus off the Pacific coast of northern Japan. Cn: % of identifiable prey to the total number; WW: % of identifiable prey to the total wet weight; F: % frequency of occurrence of identifiable prey; %IRI: % index of relative importance. In copepod category, generalized form contains calanoid copepods of morphologically general Calanus-type, specialized form contains morphologically specialized calanoid copepods such as Heterorhabdus spp.

<40mm SL ~40mm SL

Cn (%) WW (%) F (%) %IRI Cn (%) WW (%) F (%) %IRI

CRUSTACEA (TOTAL) 89.2 57.5 100 97.2 95.2 97.4

COPEPODA (TOTAL) 80.9 44.3 92.1 88.5 49.5 9.8 56.4 29.7 Gaidius sp. 0.2 0.1 1.6 Undeuchaeta sp. 0.2 0.1 1.6 Gaetanus sp. 0.2 0.0 1.6 Aetideidae (Unident.) 0.5 0.1 1.6 Calanus pacificus 26.0 8.5 47.6 13.4 1.3 35.9 Neocalanus jlemingeri 0.7 0.8 1.6 N plumchurus 0.2 0.1 1.6 Neocalanus spp. 0.5 0.2 3.2 0.5 0.2 2.6 Calanidae (Unident.) 2.8 0.2 2.6 Candacia bipinnata 0.2 0.1 1.6 C. columbiae 5.9 6.8 11.1 Candacia spp. 1.5 1.8 6.3 Eucalanus bungii 0.2 0.4 1.6 Eucalanidae (Unident.) 0.2 0.3 1.6 Euchaeta rimana 5.4 5.1 4.8 Paraeuchaeta russelli 0.9 0.2 2.6 Paraeuchaeta sp. 0.5 0.1 2.6 Euchaetidae (Unident.) 0.7 0.4 3.2 0.9 0.4 5.1 Heterorhabdus pacificus 0.2 0.1 1.6 H. papilliger 0.5 0.0 2.6 Metridia pacifica 2.5 0.7 14.3 6.0 0.8 17.9 Metridia spp. 0.5 0.1 3.2 Pleuromamma abdominalis 2.0 1.1 11.1 4.6 1.2 15.4 P. gracilis 1.0 0.7 6.3 0.5 0.0 2.6 P. quadrungulata 0.2 0.1 1.6 P. xiphias 0.7 0.7 4.8 5.1 1.7 7.7 Pleuromamma spp. 5.1 3.6 22.2 3.7 1.0 7.7 Metridinidae (Unident.) 0.5 0.0 2.6 Scolecithrix danae 2.2 1.7 9.5 Calanoid younger copepodite 0.2 0.0 1.6 (Unident.) Calanoida (generalized form) 0.5 0.1 3.2 0.9 0.3 5.1 Calanoida (specialized form) 2.0 1.7 3.2 0.5 0.3 2.6 Calanoida (Unident.) 10.8 5.5 25.4 7.9 1.9 25.6 Oithona sp. 0.2 0.1 1.6 Oncaea spp. 5.4 0.5 17.5 Corycaeus spp. 2.2 0.5 9.5 Poecilostomatoida (U nident.) 0.5 0.0 2.6 COPEPODA (Unident.) 2.2 2.1 9.5 OSTRACODA (TOTAL) 1.7 1.7 9.5 0.3 2.3 0.5 10.3 OJ Conchoecia alata major 0.2 0.1 1.6 C. pseudodiscophora 0.2 0.1 1.6 Conchoecia spp. 0.5 1.1 3.2 2.3 0.5 10.3

-153- Bull. Fac. Fish. Hokkaido Univ. 52(3), 2001.

Table 2 (Continued) <40mm SL :2:40 mm SL

Cn (%) WW (%) F (%) %IRI Cn (%) WW (%) F (%) %IRI

OSTRACODA (Unident.) 0.7 0.4 4.8

AMPHIPODA (TOTAL) 0.7 0.8 3.2 <0.1 2.8 1.9 12.8 0.5 Themisto japonica 0.2 0.2 1.6 2.8 1.9 12.8 Hyperiidea (Unident.) 0.2 0.2 1.6 AMPHIPODA (Unident.) 0.2 0.4 1.6

EUPHAUSIACEA (TOTAL) 4.4 7.3 19.0 1.7 40.3 80.6 64.1 68.8 Euphausia pacifica 1.5 3.7 6.3 32.4 66.5 41.0 E. pacifica (furcilia) 0.7 0.6 3.2 0.9 0.2 5.1 Euphausiidae (Unident.) 0.7 0.1 1.6 3.7 6.4 10.3 EUPHAUSIACEA (Unident.) 1.5 2.9 9.5 3.2 7.5 15.4

CRUSTACEA (Unident.) 1.5 3.3 7.9 2.3 2.4 12.8

CHAETOGNATHA (TOTAL) 10.3 41.4 23.8 9.5 2.3 4.7 10.3 0.6 Sagitta spp. 2.9 9.5 4.8 0.5 l.l 2.6 CHAETOGNATHA (Unident.) 7.4 32.0 19.0 1.9 3.7 7.7

POL YCHAETA (Unident.) 0.2 0.5 1.6 <0.1

TUNICATA (Unident.) 0.5 0.0 2.6 <0.1 Maurolicus japonicus 0.2 0.6 1.6 0.0

No. of identifiable prey items 408 216 No. of unid. material 9 7 No. of stomachs containing 63 39 identifiable prey items No. of stomachs examined 67 45 No. of empty stomachs 0

29.7% for large fish (Table 2). The %IRI of euphausiids significantly among stations (Kruskal-Wallis test, H = was 68.8% for large fish, but < 2% for small fish. 28.89, p

-154- UCmKAWA et al.: Feeding habits of Maurolicus japonicus

60 aI., 1994) reporting the increased importance of eu­ ~40 mm SL Fish phausiids with fish growth. Both of the predominant N=93 prey, Calanus pacijicus and E. pacijica are distributed 0 40 dominantly in the study area (c. pacijicus refers to C. u c helagolandicus, Odate, 1994). Chaetognaths of secon­ 0 dary importance by wet weight for small fish are abun­ .... ;:::l 20 dantly distributed in the present study area. The u u chaetognaths were often unidentifiable due to rapid 0 digestion, but may have been any of the abundant ...... 0 species; Sagitta elegans, Eukrohnia hamata, S. enjlata >. <40 mm SL Fish and S. minima (Kitou, 1974; Terazaki et aI., 1985; u Odate, 1994). The vertical distribution of chaetognaths C N=101 0 varies by species, ontogenetic stages and regions (Teraza­ ;:::l 40 0'" ki et aI., 1985; Terazaki, 1998), resulting in an undeter­ 0 .... mined degree of habitat overlap with M japonicus ...... Kitou (1974) reported that the highest abundance of 20 ~ chaetognaths occurred during autumn in the present study area. Therefore, the importance of chaetognaths in the diet would be partly explained by the sampling o date, although the difference in importance of 2 4 6 8 10 12 14 o chaetognaths between the size classes of M japonicus Prey length (mm) remained unexplainable. The most predominant prey for large fish, E. pacijica, undertakes diel vertical migra­ Fig. 2. Size-frequency distribution of prey ingested by Maurolicus japonicus for the two size classes of fish. tion (DVM) (Taki et al., 1998), and forms dense aggrega­ tions in the near-bottom layer during daytime (Izumi and Kodama, 1995; Taki, 1996). As to C. pacijicus, (A) 100 r- c- c- no information is available on its vertical distribution in ... the present study area. However, in the Santa Barbara Q.) .J:J 7: Basin, it has been reported to form aggregations in the 8 II 2 ;:l 50 ~ C 111 mesopelagic zone throughout the day (Alldredge et aI., t'2. ~ 1984; Fleminger, 1985; Osgood and Chekley, 1997a, b). The meso pelagic aggregations consist of diapausing 01- individuals, but a certain portion of C. pacijicus remains (B) 5 active in the surface layer throughout the year (Flemin­ 0=7 ger, 1985). In the course of a submersible observation, 4 mesopelagic fish, Leuroglossus stihilius were observed feeding actively on the aggregation of C. pacijicus in the mesopelagic layer (Alldredge et aI., 1984). Since M japonicus undertakes DVM with daytime distribution n=21 deeper than 150 m (Hamano et aI., 1992), both E. .-- n=29 pacijica and C. pacijicus would be accessible in the O+--.~r-'--.~r-.--.-.'-.-~ 6 8 10 12 14 16 surface layer at nighttime and in the deeper layer during Time of day daytime. Thus, the importance of C. pacijicus and E. pacijica in the diet of M japonicus would be ascribed to Fig. 3. Diel changes in the state of digestion of prey (A) and stomach content index (SCI) (B) in Maurolicus the vertical overlap of predator and prey throughout the japonicus. Error bars are ± ISE. day.

Acknowledgements M japonicus showed a clear ontogenetic difference in diet. The difference was due to the heavy ingestion of We thank T. Hattori, H. Imamura and the officers and euphausiids by large fish. This result agrees with the crews of the RV Wakataka-Maru for their help with previous studies on feeding habits of Maurolicus (Samy­ sampling at sea. We also thank O. Yamamura and R. shev and Schetinkin, 1971; Gj~sreter, 1981; Ikeda et Rigby for their critical reading of the earlier versions of

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-157- lm. [PiTIMi'; (JmJtl:) O)fjlj 1] ffil:mifi~, 1J:Jt, ~~-2I.lb, 9~-C A4 -tt1 ;(O)m~J£~-&! 1) Laboratory of Comparative Physiology, Graduate mL-, .jI:~ t9.Qo ;$:X, ~, ~'Ei'fi, 7- r7"o-e'» School of Fisheries Sciences, Hokkaido University -tt ~-&!m L- -C, 12;T-1 / r 1 ~- ~ 25 fJi!j!m:L"~IlfI;:E:P (::It#lFFi*~*~Ii7t*~f~.JVmf4~~~ffg~~) ,\jlUL-t.: t 0) t 9.Qo 2) Present address,' Aquaculture Department, Southeast Asian Fisheries Development Center, Tigbauan, Iloilo *f*O)t~~ 5021, Philippines ffil:mir:po)~7;k~1* (X~%Ii D) fi, 1 ~ 1) '» ~1*0)~ 3) Laboratory of Marine Biodiversity, Graduate School ilfi-:m7 /~·-71 /, A'f:-lv;f--v c ~ Iv1*O)~ilfi of Fisheries Sciences, Hokkaido University =:m7/jf-71 /, ~-lvr1*0)~ilfi7lt~7/jf-7 (::It7W~~*~Ii7t*~f4~.JVmf-i.~;~tt~!jo/J,¥~~)

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,\jlU~nt.:~1*~-2llvl"t J: lt~iJ!, ;cO):t~ilL"t 7 /jf-7 ;fpEH ~~1) 0 ffil: 1W~2) 0 W~ :J(.') 1 /1;:J:.Qm;E:fifJ-Jo :H::, ;f'1) V-vX~, ~7;k~~%, [PiT 1Mi'; (JmJtl:) O)fjlJ 2]

L11~;5.Q lt~fi-r11~X~7;k cri'l'j~Lz ~91t~X~fi, ;co) 1) ::It7WJI!*~*~Ii7t*~f4~.JVmf-i.~~~ffg~~~ 'Ei'~IlfI;:m;E:9.Qo 7;k;lO, ;: ni? O)m;E:fi;;t 1) ~T lvffil:mi (Laboratory of Comparative Physiology, Graduate 1 $ I;: *jl:9 .Q to) t L-, ::J c-ffil:mifi ;:n~~1J:L-t.: t School of Fisheries Sciences, Hokkaido University)

O)t9.Q o 2) ::It7WJI!*~*~Ii7t*~f4~.JVmf4~~I1:~!jo/J~~ (Laboratory of Marine Biodiversity, Graduate School «P.l/; of Fisheries Sciences, Hokkaido University) foxM (~XO)~ilfi/f~), fOX~~i'; (~xO):t~il fi/f~), ~xM, ~x~~i';, Mo~~I;:OO9 .QJmJtl: ~3t~,§t-;J:L1~-7-t:' ~1«-~R, ~X~'Ei't;f--7-r~2«-~R~. ~x~'Ei' (Abstract) Ii, 200 mtf)J13O)~~ 1;:9.Q ;: t iJ' L-, ;$:Xfi 3«-~iJ>i?fiG.lb.Qo ;$:XO)~, ~~~X~ ~ ~ L-It ~o ;f- - 7 - r li~mtL" 3'"'-' 10 1m (1 1m Ii 3 mtf)J13)

11vt.Qo 1 t:lc§ (~~) iJ> i?, *~O)~~~X ~ L"-~o) ~~;E:9.Q 0 JlfJl!!i~ 0 m;~il]li-21.lb 7;k1t~o ~ t.:, ;f- - 7 - r «-~:m:%~11lt .Qo ~:mnJG9 .Q~MHi9«-Cfif)]O)X~~*X~, ftl!.li/j\X~

t 9 .Q 0 ~ t.:, fi~O)mtli!j!~Or~O)i';~il] t 9 .Q 0 H [;f-- 7 - rfjlj] ~XO)±Mli, ~®'l;~, m;~;lO J: rJJlfJl!!i~f)Y'Hi, § World revision, Zoogeography, Oncorhynchus keta, ~o)l7-*X~, ;cO)ft!!.liJj\X~t 9.Qo iU~J~lHi, imi';O) Salvelinus fif)]O)mto)§~o)l7-*X~, ;cO)ft!!.lil!'!l1fi';~f)Y'Hi/j\X ~t 9.Qo ~ t.:, Mli open system (fi~l;: c 1);;t r ~11 ;$:3tO)f*iIi It7;kIt» t9.Qo MO)~1*li::J'V'»~t9.Qo 7;k;lO, ~ (1) Xr:pO){jjlVEt.Hi 10 J ;lO J: rJ I, J ~-&!m9.Q 0 i';iJ'Mr:pI;:;5.Q t ~ Ii, §~0)l7-1 ~ 1) '» ~ o;f--v c~ (2) ;$:xO)!R:5Ht Ii, * 0 r:p 0 Ij\5!ili L- ~-&!m L- -c~a

IvL", ;cO)ft!!.liA 'f:-lv 0 1 ~ 1) '» ~, ~i';~li§~o)l7- 1;:9.Qo lt~fnO)5!ili L-0);5 t t, ;cnl;:®'l; < xJi[

~Jm*X~L", ;c O)ftl!.liJj\X~ t 9 .Q 0 lifJ~~;t, 1 ::J'7;5vt.Qo

*5!ili L-: ::J. V '» ~ L"1TO) r:p:9i!: I;: jI: < 0 :m:%li"J It lf~~ 7;k It ~o ~XO)~~i';li, i';JlfJli§~o)l7-;f--v c ~ lv, M:fi§~ r:p 5!ili L-, Ij\5!ili L-: 1 ::J '7 ;5vt-ctcliffill;:jI: < ofDX o)l7-;f--vc~~ ;cO)ftl!.~A'f:-N;f--vC~Nt9.Qo~ li::J'V '» ~, ~Xli1 ~ 1) '» ~ ~-lv r t L-, ffil:JlU ~iJ!2AO)~ilfi landJ l", 3AO):t~illi I,J -C'''J7;k~., t L- -C:m:%li"J vt7;klt~o :m:%~"J It .Q~\~0);5.Q t fi~li landJ L""J7;k('o foXli9«-C loJ L""J7;k<·o ~ ~Ii, 77l:·7~~tL-, c1);;tr~"Jlt.Qo

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QUlNITIO )·2), TAKEMURA ) Gerald F. ' Akihiro ' and Akira (4) ~XO)Ai';li§~o)l7-*X~, ;co)l~iJ>li~Jm/j\X GOMI3) ~t9.Qo (5) fOX r:p , iIJ;fl!jo/J~Jmi'; (fDi';), ;cO)I~iJ>~O)mtfi

-158- fJ 7' fJ 71'. \0 lin· fD~It,Th~WB~$I~:lOIt)l ~ Fig. I, Fig. 2... ~ W ~~$~B*A 5~Ym~"nl'an~, 17' J::? 1::*90 1) 'Y ;; 1* t T -0 0 tc. t.!. L.-, i.e., e.g., etc., viz., et al. t:t t'~~~I::ffllt)i?h-O ~~Ii~~~*t L.-, 17' ~~ 1) 'Y;; f:: L.-t:tlt)o 2J~ Ii ~ t L.- llflll) tlkV ), 11% ~ ~ t fi:I.l C:jj L.-1I% HR (7) ~J:!I!i!::a:-*Tgc.%I::li17' 1) 'Y ;;1*:a:-ffllt)-Oo "";; ffl9-Oo 2J~liBP-Ell£l::~til){"tlt, liiJ;ht:tIt)J:: ?ti:~ r Jvi!:~gc.%li ~- Jv r ~1 7' 1) 'Y ;; 1*:a:-ffllt) -0 0 9 -0 0 I "J~~I::fj!~~2J~t:t c:a:-13'n~iili, -fh'fh~ 2J~t:t c~ftJ:l:: (a), (b) ... t gC.A L.-, ~ q:. A r $l'li !j!111 Fig. I (a) ~J::? l::ijlffl9-Oo /1/- r lifflIt) t:t1t):7JiJ:tm:t ~i!:~lli{.lUi SI llifllHilUm t T-O o L.-It)o fJ 5-2J~li*IJ:!I!jHf~~~.mjtt!H:::lOIt)l~ft

It -0 0 ~~ A1I%li~A~:tlYffiH:: (1), (2) ...... ~ J:: ? f::~ L.-1I% :a:-"J It-O o *Ii A4 ~~ Bl£:a:-{Rffl L.-, I ;f)cl:: I "JT"J '7 - r 70 -1! 'Y -Ij-l·E:lJijU L.- t::. ~ ~ t T -0 0 *~ ~ * 6b 9 "" l~~ t ~t:> ~ L1~(7)5Im L.-, ~*~:tlrTd7-I::~:ff~:a:-Ah-Oo -71 ~~{Rfflli~ ~:lO J:: LJ*IHO~WB~$I:::lO It) l ~ -f h'fh Fig. I, 'NNt L.-, !f-'f1::7'~-71~liJ]{Jmt L.-l{RfflL.-t:tIt)o *~ Table I ~ J:: ? I::ij IfflT -0 0 fY3~li closed system t 9 -0 0 ~, *~1ilIA:ffi"m{lliil:a:-*~ ~:tl;fljj..I::m~9 -0 0 3tii*(7)5Im ~$l'~~:a:-ijlfflT -0 t ~ lirgc.l:: J::-O o ~~3tii* [~~ijlffl~17IJ I] ~:ff:!rt I ~~riiii ~~~~~ 1) A r li*~~~1&1::-:J\5L.-lgC.~9 -0 0 ~ ...... ;: tiJ:t~1!f~hllt)-O (EH$, 1992; 583, 1993)0 ~li1l%:a:-"JltT, ~:ffft~7Jv77""'Y r t9'£*~~nlR ...... have been reported (Tanaka, 1992; Yoshida, I::Mz""-Oo fi:I.l-~:ff~~iil"~~:ff~li~~Z: t I::. <0 1993). 1) A r ~~~~* L.-:7Jli.:x~ J:: ? I:: T -0 0 83$ (1992), 583 (1993) I:: J:: hI!····· .... CD ~m~:m~~~ii According to Tanaka (1992) and Yoshida (1993);········ ~:ff~ (9'£TT$) WB~*~. ~~ (17' 1) 'Y ;;1*), ~ (% [~~ijlffl~17IJ 2] ~:ffiJ:t 2 ~~~ii li1!l~, ~-Jv r1*), ~~""-~...... ;: tiJ:t~1!f~h llt)-O Cli'L:j:j:· :j:j:J:, 1992)0 @ ~iJ:tt:tIt):m~~~ ·········have been reported (Arai and Inoue, 1992). ~:ff~ (9'£TT~) WB~*~. ~~ (17'1) 'Y ;;1*), (%) JTt:j:j: • :j:j: J: (1992) I:: J:: hI!········· (fJ'Y:J:a:-ftlt, ~-Jvr1*), ""-~. According to Arai and Inoue (1992);········ [~~~~ 1) A r ~{JlJ] [~~ijlffl~17IJ 3] ~:ff~iJ:t 3~tJJ:~~ii Okamoto, H. (1990) Notes on the demersal fishes from ...... ;: t iJ:t~1!f ~ h lit) -0 (J:!I!f i?, 1993)0 Hakodate, Hokkaido. Japan. 1. Ichthyol., 37, 123-128. ·········have been reported (Ueno et aI., 1993). Maisey, J.G. (1986) Anatomical revision of the fossil J:!l!fi? (1993) 1::J::hl!········· shark Hybodus fraasi (Chondrichthyes: Elasmobran­ According to Ueno et aI. (1993);········ chii). A mer. Mus. Novi., (2857), 1-16. Iwata, M., Komatsu, S., Collie, N.L., Nishioka, R.S. and lIiIlj.i Bern, H.A. (1987a) Ocular cataract and incomplete JJtPti:iJ~~\~t:t t ~ Ii, I~H*T -O*~$~ml::J:ft~ l' I), seawater adaptation in salmonids. Aquaculture, 66, 2), ···:a:-ftL.-, fi:I.lC:J]{~ffll£~r~I::**,fRl'IKWI), iJJtPti:J 315-317. t*.L.-l-f~~fY3:a:-. <0 JJtPti:li?Stffl-ltTI::~'J\Il1H:: t Iwata, M., Nishioka, R.S. and Bern, H.A. (l987b) Whole nb-O o animal transepithe1ial potential (TEP) of coho salmon during the parr-smolt transformation and effects of thyroxine, prolactin and hypophysectomy. Fish ~liA4~~Bl£HRmL.-, 1;J'9X I~T"J#i'i\o~~~ PyhsioL Biochem., 3, 25-38. :tlrTd7-I::~:ff~, ~11%, :ffi"m~R:a:-gC.AT-Oo ~Rli il+ ?ffE' ~:j:j:~fi" • [Ej:j:j: flit· ilii83~= • f6:fI!f$Ji 1/2~1/3 iJ:tm:t L.-It)o ~~*~, ~*~*~~, §~ I) ~ (1994) fi,n~frl:::lO It -0 A -7 r '7 7'·5 ~~~TTIIJI::f-¥ "Jlt:7J~I::"JIt)lli+7Hfcl.L.-, :ffi"m~Rl'~'J\:J C'-:a:­ ? q~.:g-. B*~, 60, 467-472. L.-ld7-l, *B*iJ~fY3llfl'ib -0 ;: t :a:-lI{f,;;;G9 -0 ;: t 0 ~11% l'i'b!l!ffOJ[ (1992) 777:J AIf'iffi1:'.iiH3Z:V!liI:: "J It) l.

-\59- 1fl" .Q iil~, (233), 1-10. mtl:l':~t:?-c @ fftfB:>c~O)~ ~~tf:lJt&~HH~i» I? PJT5EO)~~ (5jU*SJ~A) ~§l: ttJflZ ~~~(~fi~)fftfB:>c~.m~~-~,fftfB:>c~~~~, I), !lZ\~I;t"~~[lA lJ.:~, .: n~~ti I) 11~tt.:t-t1i~n;:;t fftfB:>c~~1m (1?' I) '/' :71*), ~1T~~, ~1li{/!. O)n~v;:T I) ~T }vW-m 1 $:10 J: rJ::1 1::-2 $~ An, ~ji~v;:mtf:l fjlJO)J: -:J v;:iI< 0 T.Q. [~~:>cM* I) A r O)fJIJ] Eastman, S. and Jones, J. (1993) The deep-sea benthic tiJtfflwm ichthyofauua from the continental shelf of Japan. pp. ~.~~AT.Qtt:>cmMIm~~~ft~~~~~:>C~

215-219, Westman, T. and Jackson, S. (eds), Zoogeogra­ *, fO:>c 30 *J:Jpg t T.Q 0 ~~b' 2 AO) t ~ ~i, ~:>c vi phy of deepsea fishes, Smithonian Press, Washington, ,&J ~.. fO:>Cvi ,oJ l:"~I;t~., 3AJ:JJ::O)t~vi, ~:>c D.C. l:"vi YOSHIDA et aI., fO:>CL"vi~JliI?, O)J: -:5 v;: 2A§J:JT

pgl'ilt';l±Ul (1965) '71/71 7f4. pp. 578-581, [liffEE~ 0 viMT 0 n~lmO)Mlmvi~fJJO):>C*:IO J: rJlBJ:ff~~'!IO)§

0 I) pgEEm-2JIJJ 0 pgEE'¥ (~), ~B*IfJ~~Iii, ~t~jg, * *o)h-.-:f"" I::?' }v t T.Q I:: ;t ni~ v1l;tlt)o JR. [nfftfBxmtt:>c~O)fJIJ] @ !ji1T*0);l:it~ KOMAI & AMAOKA: Decapod crustacean from the Okhotsk ~~~ (~1T~) iI~ (1?' I) '/' :71*). tf:lJt&tf:, ~1li{/!. coast

O)n~v;:TfJlJO) J: -:J v;:iI <0 [fD:>cfftfB:>cmtt:>c~ O)fJIJ] [~~:>cM* I) A r O)fJIJ] ~EEI?:~:77?Amm-0)~~~D~I)/~~:IOJ:rJ Maruyama, M. (1994) Fishes of the north Pacific (in 5E:i: Japanese). Hokuryukan, Hakodate. ~**®CIT1t1h~ (1999) ~~tffi.t~ Eril (~PlG 10 ~)jtJt&). ~~-t1t1h~, *JR. ~11T.Q 7 D '/' I:: -f -1 A:7 vi, §l:}!I!}*h-O)fi~W-m t -3&l.,t.: ~ 0) t T.Q o 7 D '/' I::-f -1 A:7 vi 3.51 /1-L",

~ma}t~ MS-DOS it>.Q It) vi Apple Macintosh 7 ~ -? '/' r t T .Q 0 ~~B)j:>Cfj:fD:>cfftfB:>Cv;::IOlt) ~ ~~:>c t l." -:j)5 l., ~~:i' 7D'/'I::-7'-1A:70)7«'}H;:~, ~~~~~, W-mO)~

%n~v;:?' 1 :1'tTt> l., t.: ~ 0) ~11T 0 1m, 7 71}v~:IO J: rJW-m1'FPlGv;:~m l.,t.: 'J 7 r '/ J. 7 ~ [~~B)j:>c O)fJIJ] B)j~T.Qo~tf:lT.Q7D'/'I::-f-1A:7~~flf'/':77'/' Figure Captions :1'::1 I::-~ t I), ~P,\jlU~7Bif;:j; L"~~O)-¥5tv;:f*~l.,~:10 Fig. l. Map of Funka Bay and offshore, showing local­ ities and contours of depth(m). Fig. 2. Distribution of sea bottom sediments in Funka ~

Bay and offshore. t3<:lEvi=t3<:;:j; l:"~~b'1T-:5 0 t3<:lEO)~[l%vi B*I~m~

0: data from this study, ~p,\jlUt3<:lE~[l% (JIS Z 8208-1965) v;: J: I), *ilT.Q 0 t3<:lE .: data from Hydrographic Department, Maritime vi~~UlET.Q o)b'§I¥Jl:"it>.Q b) I?, *1*~*{:jj0)c&~

Safety Agency, Japan(1981). I;t c fi:i!!:E ~t .Q 0

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