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, (MOLLUSCA: CEPHALOPODA) FROM THE SOUTHERN CARIBBEAN AND SURINAM Gilbert L. Voss ABSTRACT A new species of ocellated octopus, 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 genus 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 animal 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 a ~:..:....- d .,. ;\ -'''.. / ....•.....~...••...••.....' ./ 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 a b : .." \.\k"",.,..\ ~ ~I~~:..._-'...~.;l:,\ ·~(F:~t~~?;:\.,<:..{.. \ \......': ..' ..:.~:''.._... ··, . ..:,~' " " . '., '. ~i..... , ... .' ~:~ cr .. '. ..,: :.1 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 animals 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.