BULLETIN OF MARINE SCIENCE, 25(3): 346-352, 1975

BIOLOGICAL RESULTS OF THE UNIVERSITY OF MIAMI DEEP-SEA EXPEDITIONS. 115. EUAXOCTOPUS PILLSBURY AE, NEW SPECIES, (: CEPHALOPODA) FROM THE SOUTHERN CARIBBEAN AND SURINAM

Gilbert L. Voss

ABSTRACT A new species of ocellated , Euaxoctoplls pillsbllryae, is described from material collected from the R/V JOHN ELLIOTT PILLSBURY in the tropical Western Atlantic. It is compared with its nearest relative, Ellaxoctoplls panllmensis, from the Eastern Pacific. The EUllxoctopus is emended in order to contain the new species; tbe genus is tbe first in the octopodines to contain species in which either the third right or the third left arm is hectocotylized.

While completing a study of the cephalo- try net, July 10, 1968, USNM 729100.-Paratypes, I female, mantle length 18 mm, PILLSBURYSta. pods of Surinam based upon collections 349, g031.6'N, 7r02'W in the Gulf of Uraba in from Leiden and Utrecht, I had occasion to 53 m with ]0' try net, July 1 I, 1966. UMML examine the octo pods taken from those 31.620.-1 female, mantle length 24 mOl, PILLS- BURYSta. 662, 6°49'N, 54°26.5'W off the Surinam waters during a cruise of the research vessel River in 44 m with 10' try net, July 10, 1968. JOHN ELLIOTT PILLSBURY. Among them UMML 1180.-1 female, mantle length 17 mOl, were several specimens of a small-bodied, PILLSBURYSta. 712, IJD08'N, 63°18'W off eastern Venezuela in 27 m with 10' try net, July 19, 1968. long-armed species that at first appeared to UMML 1179. be can specific with Euaxoctopus panamensis described by me (Voss, 1971, p. 25) from Description.-Only four specimens of this the Gulf of Panama. Further study showed species of small octopus are known. Of these, that they represented a new species closely only the female with a mantle length of 17 allied to the Pacific form but showing some mm was in reasonably good condition with striking differences. Reexamination of other only part of the right ventral arm missing small octopods taken during our previous but even this specimen was badly distorted. cruises revealed an additional specimen from In all cases, therefore, arm lengths are only the Gulf of UraM originally recorded by me approximations. Measurements and indices erroneously (Voss, 1968, p. 654) under the are given in Tables 1 & 2. name Octopus deiilippi. The mantle is small, about 10% of the The new species is the second twin species total length, and is somewhat pyriform in of octopod known to occur in the isthmian outline with a blunt point posteriorly. It is region and presents some unusual taxonomic widest at about its middle. The neck is con- difficulties. The measurements and indices stricted, accentuating the large, projecting eyes. The head is somewhat elongated, given are those defined by Voss (1963, p. especially in the neck region, and this, to- 11). The illustrations are mine. gether with the elongate brachial crown and slender body, forms a long slender ElUtXOCtOJ1US pillsburYlle, new specIes Figures 1-4 resembling certain Pacific Ocean species. The funnel is long, slender, but very mus- Octopus defilippi, Voss, 1968, p. 654 (/lOll Octo- cular. It is free anteriorly for about one- pus defilippi Verany, 1851). third of its length. Posteriorly the lateral Material exami/led.-HoLOTYPE, male, mantle margins flare strongly and are turned down- length 24 mOl, PILLSBURY Sta. 662, 6°49'N, 54°26.5'W off Surinam River, in 44 m with 10' ward and forward. These wings fit into 346 voss: A NEW SPECIES OF OCELLATED OCTOPUS 347

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h: I .'...J Figure 2. Euaxoctoplls piflsbllryae, new species: a, dorsal view of mantle showing ocelli; b, hectocotylus of male; c, upper mandible; d, lower mandible.

any of the four specimens but appears to be in the form of a small sharply pointed W. Figure I. Lateral view of Eliaxoctoplis pills- The arms are very long and slender, taper- (II/ryac, new species, 17 mm mantle length, from Sta. P-712. ing to very attenuate, delicate tips. The arms are laterally compressed and rounded ab- corresponding depressions in the internal orally. Because of the tendency of the arms mantle wall and constitute a moderately well- to break off, the arm order could not be ob- developed mantle-funnel locking apparatus. tained except for the female with a mantle The funnel organ is not clearly defined in length of 17 mm. This specimen had an arm 348 BULLETIN OF MARINE SCIENCE, VOL. 25, NO.3, 1975

Table I. Measurements (in mm) of 4 specimens of Eliaxoctoplis pillsbllryae, new species

Station No. P-662 P-349 P-662 P·712 Sex if if 'i' 'i' Mantle length 24 18 24 17 Mantle width ]4 12 14.5 12 Head width 9.5 9 9.5 7.5 Arm length T 163 154 57R 87 128+ 16+ 136 145 II 36+ 185 16R 43R 60+ 110+ ]54 200 TIT 15+ 48 173+ 28 68+ 56+ 115 190 IV 28+ 18+ 79+ 81R 67+ 44+ 190 78+ Web depth A 9 11 11 B 10 10 9 9 C 9 8 10 9 D 10 6 ]1 7.5 E 9 6 10.5 8 Gills 7 7 7 Heel. Arm length 48 28 Ligula length 3.3 2.8 Calamus length 1.5 Total length 211 219 Arm width 4 2.5 3.5 2.5 Sucker diameter 1.5 1.6 1.6 1.1 Arm order 2.1.?? 2.4.3.1 Web formula B =D.A =C=E A.B.C.D =E A.B =C.E.D Penis length 3.7 2.9 Sperm. length 7.5

R = regenerated tip + = tip broken off order of 1.4.3.2 calculated from the longest low bases. The two males have no specially arm of each pair. enlarged suckers. The suckers are very small, numerous, and The web is very small, its deepest sector clearly set apart. They face orally on erect less than 6% of the longest arm. The various

Table 2. Indices of bodily proportions and counts of 4 specimens of Eliaxoctoplis pillsbllryae, new species.

Station No. P-662 P-349 P·662 P·712 Sex rJ if 'i' 'i' Mantle length 24 18 24 17 Mantle width index 58.3 66.9 60.6 70.5 Head width index 39.6 50.0 39.6 44.2 Arm length index 87.8 91.2 Mantle arm index 12.9 8.7 Arm width index 16.6 13.9 14.6 14.7 Hecl. arm index 26.1 16.2 Ligula length index 6.8 10.0 Calamus length index 45.5 Sucker index 6.3 8.9 6.7 6.5 Web depth index 5.4 5.6 Penis length index 15.4 16.1 Sperm. length index 31.2 voss: A NEW SPECIES OF OCELLATED OCTOPUS 349

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Figure 3. ElIaxocloplIs pi/lsbllryae, new species: a, digestive tract; b, female genitalia; c, radula; d, penis.

web orders are given in Table 1. It appears ~ •••• l \ '(";)'1 as if the web extends as a low ridge along the ventral margin of the arms but this could not be determined because of the condition of the specimens. The third right arm is hectocotylized. It is much shorter than the other arms, cor- respondingly stouter, and is bordered ven- trally by a distinct inrolled web forming I ,;.I t I~ ",;:...1. the spermatophoral groove. The ligula is lanceolate with raised oral margins; the oral surface is crossed by numerous transverse ~j~~; \~ ...... • ¥ plicae. The calamus is well-developed, tri- '\\ ,.... angular, sharply pointed, with strongly in- '\"1,': rolled margins. )I{ 't'l The gills contain 7 lamellae on the outer /Il "'?-f.1 demibranch. ( ..:;;;,#f;:'i:.....

~ Figure 4. ElIaxocloplIs pillsburyae, new species: a, spermatophore, b, details of spermatophore horn. 350 BULLETIN OF MARINE SCIENCE, YOLo 25, NO.3, 1975

The digestive tract was dissected out of The color of the in preservation, one specimen and the buccal mass removed with much of the epidermis removed, is from another. The beaks show no strong grayish brown or brownish gray with a fine features. The radula shows an A3-4 seria- reticulate pattern superimposed. About mid- tion over most of the length of the ribbon. way between the head and the posterior end The lateral cusps on the rachidian are prom- of the mantle are two large oval splotches inent. The second laterals have elongated of dark gray outlined by a thin, slightly bases; the marginal plates are long and raised, unpigmented ridge of flesh. The narrow. ridge is roughly C-shaped, corresponding to Both anterior and posterior salivary glands the bluish ring in the ocellus of Octopus are present; the latter are of moderate size hummelincki Adam. Unlike the somewhat and somewhat triangular. The esophagus is similar ocellus of Euaxoctopus panamensis, expanded into a distinct crop complete with there is no indication of a central pore or a large anteriorly directed diverticulum. Pos- papilla. There appears to be little or no ex- terior to the crop, which is midway between ternal sculpture. the buccal mass and the stomach, the esoph- agus becomes slender and then expands into Discussion.-In 1971 (p. 25) I described a thin-walled stomach followed by a tightly a new genus and species of octopod, Euax- coiled spiral caecum. The intestine is first octopus panamensis, from the Gulf of thin-walled but becomes enlarged and Panama. It was characterized, among other heavier. The duct from the ink sac enters features, by the possession of two semi- the intestine just prior to the anus. The ink circular ocelli on the dorsum of the mantle, sac is rather large and lies on the large very long slender arms, and the hectocotyli- liver sunken into its surface and enclosed zation of the third left arm. As hectocotyli- within its sheath. zation of the third left arm is an unusual The male and female genitalia were dis- feature in the octopodines, possessed only by sected out. The penis and its diverticulum Scaeurgus and Pteroctopus, the generic status are small and compact. Needham's sac was of the species seemed clear. filled with spermatophores; their structure The present species is very closely allied is shown in the figure. to and seems undoubtedly The female genitalia consist of a large E. panamensis, ovary contained within its membrane. The to represent a twin species, similar to the proximal oviducts terminate in a dark- relationship shown for Octopus chierchiae colored oviducal gland followed by long and O. zonatus (Voss, 1968). Table 3 distal oviducts. There were no developed clearly shows these relationships. eggs. The two species may be easily distin-

Table 3. Characters showing the relationships of EllaxoctoplIs pallamellsis and E. pillsbllryae

E. pmwmensis E. pillsbllr)'ae

1. Arms very long and slender 1. Arms very long and slender (ALI 80.0-84.0) (ALI 87.8-91.2) 2. Web very shallow 2. Web very shallow (WDT 8.7-8.8) (WDI 5.4-5.6) 3. Paired semicircular ocelli 3. Paired semicircular ocelli on mantle on mantle 4. Large, distinct crop 4. Large, distinct crop 5. Penis very blunt with large 5. Penis very blunt with large diverticulum diverticulum 6. Spermatophore horn with flat 6. Spermatophore horn with flat coils coils voss: A NEW SPECIES OF OCELLATED OCTOPUS 35]

Table 4. Characters distinguishing Euaxoctopus panamensis and E. pi/lsburyae ------~_._------E. pan ameli sis E. pillshurJ1ae

I. Left third arm hectocotylized l. Right third arm hectocotylized 2. Funnel organ VV-shaped 2. Funnel organ W-shaped (?) 3. Ocellus hook-shaped with 3. Ocellus C-shaped without central pore central pore 4. Liver slender, deeply cleft 4. Liver stout, not cleft 5. Spermatophore hom tightly 5. Spermatophore horn loosely coiled coiled 6. Gill lamellae ] 1-]3 6. Gill lamellae 7 guished by the characteristics shown in table The new species is given the name pills- 4. buryae for the research vessel JOHN ELLIOTT Despite these differences it is obvious that PILLSBURYon whose cruises all of the known the two species are very closely related and specimens were taken. probably were derived from a common an- This new species raises to ten the number cestral species separated only since the final of benthic shelf octo pods known from the emergence of the isthmus of Panama. As a tropical western Atlantic. The following key result, even though the hectocotylization of may assist in their identification. the arms is reversed between the two species, a character of great significance in the octo- KEY TO THE BENTHIC SHELF podines and formerly considered to be a OCTOPODS OF THE TROPICAL generic character, it is obviously not possible WESTERN ATLANTIC to place them in separate genera. If Euax- ]a. Ocelli or dark spots or rings present either octopus were placed in the synonymy of on the dorsum of the mantle or side of head below and in front of the eyes .... __.. 2 Octopus, the latter genus would be placed Ib. No ocelli or dark spot or rings 4 in the compromising situation of possessing 2a. A pair of narrow semicircular or C-shaped a single species with the third left arm ocelli on the dorsum of the mantle; ani- hectocotyl ized. mals small; gills 7; ligula index 6.8-10 .... ._ Euaxoctopus pillsburyae, new species 1 believe that the only logical solution is 2b. An ocellus or dark spot or ring on each to retain the genus Euaxoctopus, including side of the head between the eye and the second and third arms __. .. 3 E. pillsburyae within it, and to emend the 3a. Ocellus with a narrow blue ring within generic characters. the spot; animals small; gills 6-7; ligula index 4-5; eggs small, 2-3 mm _ Genus Euaxoctopus Voss, 1971 --- Octopus 11lImmelincki Adam 3b. Ocellus without a blue ring; animals large; Diagnosis.-Small octopodines with small gills 9-10; ligula index 1.4-1.9; eggs large, body and long slender arms; a pair of semi- to 17 mm Octopus maya Voss and Solis 4a. Mantle, head, and arms crossed by broad circular ocelli on dorsum of mantle; third bars of chocolate brown on a light back- right or left arm hectotylized; spermatophore ground; animals small; gills 6-7; ligula in- dex 6-9; eggs moderate, about 6 mm horn formed of flat tightly or loosely coiled long Dc/opus ZOlla/us Voss tube; a large, distinct crop with diverticulum 4b. No chocolate brown bars crossing mantle, present. head, and arms 5 Sa. Mantle, head, and arms covered with close- Type species.-Euaxoctopus panamensis set papillae; dark purplish or brownish band on dorsal side of arms _ Voss, 1971. By monotypy. ______Dc/opus burryi Voss 5b. Mantle, head, and arms not covered with This is the tenth species of shelf octo- close-set papiIlae; no dark band on dorsal podine to be reported from the tropical side of arms 6 Western Atlantic and the third species of 6a. First arms always largest and usually longest; stoutest or coequally stoutest with ocellated octopus from the region. second arm; animals medium to large; 352 BULLETIN OF MARINE SCIENCE, VOL. 25, NO.3, 1975

gills 9-13; ligula index up to 14; eggs small resulting from the National Geographic Society- ______.. Octopus macropus Risso University of Miami Deep-Sea Biology Program. 6b. Second and/or third arms longest, usually The ship time was made available by grants conspicuously so 7 GB 1204 and GB 7082 from the National Science 7a. Second and third arms much longer and Foundation. The research was supported by Na- stouter than first and fourth arms; animals medium to large; gills 6-8; ligula index tional Science Foundation grant G B 24994. The 3-4; eggs large, to 10-14 mm .. _ writer wishes to thank the above named institutions .. . . Octopus briarells (Robson) for their continuing interest and support. 7b. Second and third arms not markedly longer and stouter than other arms 8 LITERA TURE CITED 8a. Arms are long and slender, asymmetrical in length; mantle small; animals small to Voss, G. L. 1963. of the Philip- medium; gills 11; ligula index 1.8-2.5; pine Islands. Bull. U.S. Nat. Mus. 234: 1-180, eggs not known Octopus defilippi Verany 4 pIs., 36 text-figs. 8b. Arms not conspicuously long and slender; 1968. Octopods from the R/V PILLS- arms symmetrical or nearly so in length 9 BURY southwestern Caribbean cruise, 1966, 9a. Arms stout, moderately short; animal me- dium to large; gills 7-11; ligula index under with a description of a new species, Dc/opus 2.5; eggs small, 3 mm or less _ zonafUS. Bull. mar. Sci. 18: 645-659, 4 text- ______... . ._._.. . Octopus vulgaris Cuvier figs. 9b. Arms short; animal small; gills 5-7; ligula 1971. Cephalopods collected by the index 4-7; eggs moderately large, 5-10 R/V JOHN ELLlOlT PILLSBURY in the Gulf mm . Octopus jOllbini Robson of Panama in 1967. Bull. Mar. Sci. 21: 1-34, 6 text figs. ACKNOWLEDGMENT ADDRESS: Rosenstiel School of Marine and Atmo- This is a scientific contribution from the Rosen- spheric Science, University of Miami. Division of stiel School of Marine and Atmospheric Science, Biology and Living Resources, 4600 Rickenbacker University of Miami. This paper is one of a series Causeway, Miami. Florida 33149.