Galiteuthis pacifica (Robson 1948)

Taonidium pacificum Robson, 1948, p.130

DESCRIPTION.—The slender mantle, broadest in the anterior half, tapers to a point posteriorly and has an extremely thin but muscular wall. The mantle margin is fused to the nuchal region and at the lateral edges of the funnel. Cartilaginous tubercles are lacking at all of these points.

The fins are small and lanceolate; they are about 25% of the M.L. in length and 20% of the M.L. in width. There are no anterior or posterior lobes. The pen, which is visible along the middorsal line, extends slightly posterior to the fins, but this may be an artifact of preservation.

The funnel is small, but reaches nearly to the anterior margin of the eyes. The funnel is free from the head laterally. The dorsal pad of the funnel organ has roughly an inverted U-shape. Usually a small papilla arises from the center of the anterior portion of the pad. The ventral pads are small and oval. There is no funnel valve.

The head is short and the eyes are relatively small. The eyes are not clearly talked in any of the available specimens since they lack extended optic tracts, although the eyes project at a 45° angle to the body axis. A small olfactory papilla arises posterior to each eye.

The arms are short and muscular. Low gelatinous swimming keels are present on the distal portions of arms I–III, and lateral keels are present on arms IV. Low, trabeculate, protective membranes are present on all of the arms. A low, interbrachial web exists between arms I–II. The arm formula is IV>III>II>I. The suckers are arranged biserially on each arm. On the midportions of the arm, the suckers are large, and the inner chitinous rings are smooth and have broad apertures.

The tentacles are short and have only slightly expanded clubs. An ill-defined carpal locking-apparatus is present at the base of the manus which seems to include 7–9 suckers; the knobs are indistinct. Proximally, the carpal suckers merge with paired suckers that extend along more than two-thirds of the tentacular stalk. These suckers alternate with indistinct knobs and can therefore be considered as an extension of the carpal cluster. There are 48–74 suckers on the tentacular stalk. The median 2 rows on the manus consist of apparently 5 hooks each, although the clubs have been damaged so that the exact number is uncertain. Lateral to the hooks on either side is a marginal series of suckers. The dactylus is very short and appears to have from 14–24 suckers. The inner chitinous rings of the marginal and carpal suckers each have a few short, truncate, and broadly separated teeth around the entire margin; those of the distal margin are the largest.

On the ventral surface of each eye is a U-shaped photophore that extends from the posterior margin along the medial edge to the antrior margin of the eye. A crescent-shape patch of tissue which is limited medially by the photogenic band just described is apparently part of this photophore, although distinctly different in appearance. In the largest specimen, the more distal photophores, characteristic of most members of the subfamily, is just beginning to develop. This photophore is also composed of 2 parts: a short distal bar and a proximal oval patch. Combined, these have a circular outline.

The specimens have scattered reddish brown chromatophores.

The buccal connectives attach to the dorsal borders of arm I and II and to the ventral borders of arms III and IV.

TYPE LOCALITY.—Off Cocos Island, eastern tropical Pacific.

LOCATION OF TYPE.—Numbers 1948.7.8.1 and 2. British Museum (Natural History).

Galiteuthis pacifica is a little known species of glass squid from the family Cranchiidae. It has never been fully described despite having a wide distribution in the tropical Indo-Pacific. The males grow to at least 333mm in mantle length.

Known from seamounts and knolls