Promachoteuthis sloani, a new species of the squid familyPromachoteuthidae (Mollusca: Cephalopoda)

Richard E. Young, Michael Vecchione, and Uwe Piatkowski

(REY) Dept. of Oceanography, University of Hawaii, Honolulu, Hawaii 96822, U.S.A.,

e-mail: ryoung@hawaii.edu;

(MV) Systematics Laboratory, National Marine Fisheries Service, National Museum of Natural

History, Washington, D.C. 20013-7012, U.S.A., e-mail: vecchiom@si.edu;

(UP) Leibniz-Institut fur Meereswissenschaften, IFM-GEOMAR, Kiel, Germany,

e-mail: upiatkowski@ifm-geomar.de

Abstract.—We describe Promachoteuthis sloani, a new species of oegopsid

squid in the family Promachoteuthidae. The new species is based on two

specimens with the following characters that are unique within the family:

each tentacle with two series of complex papillae in the proximal 80%, andeach tentacle with pigmented ridges dorsolateral to the papillae that break

into papillae distally.

Promachoteuthids are poorly known

squids taken from temperate to near

Polar regions of the Atlantic and Pacific

oceans (Roper & Young 1968). They are

weakly muscled squids thought to reside

at bathypelagic depths; all have been

taken in open trawls that reached maxi-

mum depths between 1400 and 3650 m.

The smallest known specimen has a man-

tle length (ML) of 10.5 mm (form B of

Young & Vecchione 2003a), and the

largest, 102 mm ML (the new species

described herein, paratype). One female

(form D of Young & Vecchione 2003a)

was mature at 42 mm ML whereas the

large paratype female is immature. Pro-

machoteuthids mostly have large fins,

peculiar tentacular clubs, small eyes with

an eye opening that may be a simple pore,

and lenses covered by translucent eyelids

(i.e., pseudocorneas). Currently, only

a single species (P. megaptera) is named

(Okutani 1983, Voss 1992), but five

additional forms are known (Salcedo-

Vargas & Guerrero-Kommritz 2000,

Young & Vecchione 2003b). Four of the

five forms are known from single speci-

mens. Here we present diagnoses and

brief descriptions of one of the forms,

based on the capture of a second speci-

men in virtually perfect condition. Addi-

tional information is available on the

world-wide web at: http://tolweb.org/

Promachoteuthis_sloani/19529.

Materials and Methods

The holotype (Fig. 1, Bergen Musem

cat. no. ZMBN 77622), an immature

female, 58 mm ML, was captured in the

North Atlantic Ocean by the R/V G. O.

SARS (MAR-ECO cruise super station

14, local station 341) at 53u059N, 36u469W

in a trawl that fished to a maximum depth

of 2792 m, in 2004. The paratype (Fig. 2,National Museum of Natural History cat.

no. USNM 1086443), an immature fe-

male, 104 mm ML, was taken at the R/V

Walter Herwig station 714, 46u009N,

15u499W, North Atlantic Ocean, in a trawl

that fished to 2650 m, in 1973.

Systematics

Promachoteuthidae Naef, 1912

Diagnosis.—Oegopsid squids with un-expanded tentacular clubs bearing nu-

PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON119(2):287–292. 2006.

merous suckers in irregular series. Clubswithout keels, terminal pads, proximallocking apparatus, or protective mem-branes. Oval funnel locking-apparatuswithout interior bumps (tragus and anti-tragus). Head and eyes extremely small;eye lenses covered by translucent mem-branes (pseudocorneas). Ink sac, anal

flaps, and photophores absent. Ventralbuccal-crown connectives connect to theventral margins of arms IV.

Promachoteuthis Hoyle, 1885.

Monogeneric family. See family diag-

nosis.

Fig. 1. Promachoteuthis sloani. Holotype, various views of the recently captured squid before fixation:

A, predominately ventral view; B, dorsal view; C, side view. Note dark pigmentation, small head, thick

tentacles and numerous large papillae on tentacles.

288 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON

Promachoteuthis sloani, new species

Promachoteuthis sp. A: Toll, 1982.—

Voss, 1992.

Diagnosis.—Mantle free from head in

nuchal region. Arm suckers in 3–4 series

in central region of arm. Fin length ca.

60–70% ML. Tentacles bordered by

complex papillae and pigmented dorso-

lateral ridges that break up into papillae

distally.

Description.—Each tentacle with two

series of long papillae (Fig. 3a) near oral

midline at tentacle base but diverging to

be lateral to club; papillae often with

stubby branches in holotype but becom-

ing flattened, highly branching; some

papillae merging to become short com-

plex membranes in paratype (Fig. 3b).

Darkly pigmented ridges present along

lateral margins of aboral surface of each

tentacle (Fig. 1a, c); distally the ridges

break into small papillae. Pigmented

ridges in holotype extend approximately

over proximal 80% of tentacle; in para-

type pigmented ridges less prominent,

restricted to middle third of tentacle.

Club suckers on white stalks emerging

from small, white, circular patches on

pigmented club (Fig. 3a). Narrow, elon-

gate flaps scattered between suckers in

paratype but flaps absent in holotype.

Fig. 2. Promachoteuthis sloani. Paratype, drawings of preserved squid: A, dorsal view; B, ventral view.

Drawings by Keiko Hiratsuka Moore, National Marine Fisheries Service.

VOLUME 119, NUMBER 2 289

Fig. 3. Promachoteuthis sloani. A, oral view of the tentacle, holotype; B, oral view of tentacle, paratype;

C, oral view of large club sucker, paratype; D, oral view of large arm sucker, paratype; E, lateral view of eye,

holotype after preservation; F, lateral view of lower beak of paratype, rostral length 9 mm; G, lateral view of

upper beak of paratype, rostral length 18 mm. In Fig. 3e upper arrow points to eye opening, middle arrow to

pupil and lower arrow to lens. Note large difference in shape of papillae that line tentacle between Fig. 3a

and b; difference presumably due to squid size.

290 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON

Club suckers with irregular margins on

inner rings without well-defined teeth

(Fig. 3c). Club diameter narrows some-

what abruptly distally, where suckers

become more densely packed, forming

a nearly cylindrical distal end.

Arms thick, without keels and with

low, thick protective membranes. Arms

with three or four rather irregular sucker

series in mid-region, sometimes appearing

as up to six series. Arm suckers with

smooth inner rings having appearance of

fused, truncated teeth (Fig. 3d).

Fins large. Large anterior lobes pres-

ent; posterior lobes absent in holotype,

but small, distinct posterior lobes present

in paratype.

Head extremely small with small eyes

bulging laterally from head. Eyelid form-

ing small, circular opening. Eyelid over

lens opaque but with somewhat clearer

central region (pseudocornea). Lower

beak (Fig. 3f) without lateral wall fold

or ridge; with convex margin on inner jaw

edge. Upper beak (Fig. 3g) with short

rostrum; with hood margin high above

lateral wall crest.

General pigmentation purple-brown

(Fig. 1). Pigment in epithelial cells not

chromatophores; chromatophores appar-

ently absent. Pigmentation light to absent

over eye lenses, aboral base of tentacles

and arms IV, distal ends of tentacles;

white line down aboral midline of tenta-

cles over proximal 60% of tentacle length.

Surfaces within the mantle cavity heavily

pigmented.

Measurements(mm).—Holotype: Man-

tle Length (ML) 58, Mantle Width (MW)

ca. 18, Head Width (HW) 13, Fin Length

(FL) 33, Fin Width (FW) 54, Arm I 32,

Arm II 36, Arm III 31, Arm IV 35,

Tentacle Length (TL) 60, Club Length

(CL) 37. Paratype: ML 102, FL 70, FW

121, Arm I 92, Arm II 93, Arm III 88,

Arm IV 90, TL 148, CL 71, Gladius

Length 93.5. Gladius Width (GW) ante-

rior 7.4. GW posterior 10.3 (gladius

measurements from Toll, 1982).

Etymology.—Promachoteuthis sloani is

named in honor of the A. P. Sloan

Foundation in recognition of its generous

support of the Census of Marine Life

(CoML) and its MAR-ECO Program

under which the holotype was captured.

The CoML has done much to promoteour understanding of oceanic biogeogra-

phy and biodiversity of the oceans in

general.

Discussion

Promachoteuthis sloani differs from the

only other named species in the family by

the large number of sucker series on the

arms (three to four or more vs two) and

its peculiar tentacles, especially the pres-

ence of the papillae-series of the tentacles

and the lack of proximal pigment-bands.It differs from all four unnamed forms by

the free dorsal mantle margin in the

nuchal region, among other characters

(Young & Vecchione 2003a).

Little can be inferred about the biology

of this species, but the very short rostra

on the beaks suggest a powerful masti-

cating ability.

Acknowledgments

We thank the science team, officers and

crew of the R/V G. O. SARS, MAR-ECO

cruise, on which the holotype was cap-

tured and especially Odd Aksel Bergstad

for his leadership of the project. C. F. E.Roper collected the paratype. We also

thank Angel Guerra and an anonymous

reviewer for their comments on the

manuscript.

Literature Cited

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Expedition. Report on the scientific results of

the voyage of H. M. S. Challenger during the

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figures.

Naef, A. 1912. Teuthologische Notizen. 1. Die

familien Myopsiden.—Zoologischer Anzeiger

39:241–244.

VOLUME 119, NUMBER 2 291

Okutani, T. 1983. Rare and interesting squid from

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megaptera Hoyle, 1885 (Oegopsida: Proma-

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Young, R. E., & M. Vecchione. 2003a. Promachoteu-

thidae. http://tolweb.org/Promachoteuthidae/

19454

———, & ———. 2003b. Promachoteuthis sp. A.

http://tolweb.org/Promachoteuthis_sloani/

19529

Associate Editor: Stephen L. Gardiner

292 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON