Cockatoo Squid

Galiteuthis phyllura Berry, 1911

Galiteuthis phyllura Berry, 1911, p.592; 1912, p.315, text-figs. 17–18, pl.46, figs. 1–3, pl.54, figs. 5–6, pl.56.

Galiteuthis armata [parts],—Pfeffer, 1912, p.731.—Pearcy, 1965, p.262.

DESCRIPTION.—The mantle is long and slender; its muscular portion tapers to a point just past the anterior ends of the fins. The very thin but muscular mantle is fused to the head at the nuchal region and to the lateral corners of the funnel. Each of the latter 2 areas is marked by a fiat cartilaginous pad with 2–A small tuebrcules at its anterior end.

The fins are lanceolate, extremely long (41–47% of the M.L. in specimens greater than 100 mm M.L.), and slender (width 28–35% of the M.L. in specimens greater than 100 mm M.L.), and lack anterior or posterior lobes. The fins become very antenuate posteriorly, but extend to the tip of the pen.

The funnel is moderate in size, reaching approximately to the level of the midpoint of the eyes. The dorsal pad of the funnel organ has an inverted U-shape with rounded lateral arms. Three large, slightly flattened papillae are present, one on each lateral arm and one on the anterior midline. The dorsal pads are nearly oval in shape. There is no funnel valve. The funnel is free from the head laterally.

The head consists almost entirely of 2 very large, bulging eyes which are directed slightly forward. The eyes nearly touch each other in the ventral midline. In specimens up to about 60–65 mm M.L., the eyes are set on stalks. The eye opening is rather small and has an anterior sinus. From the skin over the midposterior surface of each eye arises an “olfactory” papilla which has a cup-shape terminal portion set on a swollen stalk.

The arms are relatively short, but muscular. The arm formula is IV>III>II>I. All arms possess large trabeculate protective membranes which are better developed on the ventral border of each arm. Arms I–III appear to have low, gelatinous aboral keels. Narrow lateral keels are present throughout the length of arms IV. Arm suckers are biserially arranged.

The suckers are globular, but have rather large apertures. The largest suckers of arms IV occur in the middle of the arms. The chitinous rings are smooth. In the larger of the males, the tips of arms I–II narrow abruptly and possess very small suckers in 2 rows. This distal area gives the impression that the arm tips have been lost and are in a state of regeneration; however, these tips are affected identically among opposite membrs of arms I and II and in all of the larger males (3 specimens). An Atlantic specimen of G. armata (also a male) shows the same feature. Therefore, it appears that this modification of the arm tips is a type of hectocotylization. A low web is present which is most noticeable between arms I–II.

The tentacles are short and muscular. The clubs are only slightly expanded and have narrow, potective membranes which extend the full length of the club along both margins and contain very broad trabeculae. A minute keel is present at the extreme tip of the club. The manus bears 2 rows of large hooks with 1–2 suckers in each marginal series at the proximal end. In young specimens, the marginal series are complete. Hooks first develop at approximately 40–50 mm M.L. The dactylus is short and bears from 22–32 small suckers arranged in 4 longitudinal rows. The inner chitinous rings of the dactyl suckers have generally 4 slender, widely separated truncate teeth on the distal margin, with 1–2 smaller teeth on each lateral margin. The proximal margin is slightly irregular, but lacks definite teeth. A distinct carpal cluster consists of 7–10 suckers and pads. Suckers are arranged in pairs along about the distal 70% of each tentacular stalk on the oral surface; the number of these suckers varies generally from 36–44. The suckers alternate with low, indistinct knobs.

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

There are 2 photophores on each eye. The more distal organ lies just ventral to the lens and is approximately bar-shape, but may curve slightly and is divided into 2 sections. The larger photophore occupies almost the entire medial ventral surface of the eye. It has a broad, crescent shape and is thickened on its medial side.

In preservation, G. phyllura has many reddish brown chromatophores distributed over the head, arms, tentacles, and dorsal surface of the fins. The mantle has only a few large scattered chromatophores of the same color.

All specimens examined are immature.

TYPE LOCALITY.—Off Point Pinos, Monterey Bay, California.

LOCATION OF TYPE.—United States National Museum 214325.

Galiteuthis phyllura, also known as the cockatoo squid, is a species of glass squid, possibly the largest in the genus.

In 1984, the Russian stern-trawler Novoulianovsk brought up the remains of a gigantic specimen of G. phyllura from a depth of 1000–1300 m in the Sea of Okhotsk. Based on this material, which consisted of a 40 cm long arm and 115 cm tentacle, Kir Nesis estimated the mantle length at 265–275 cm, and the total length at over 4 m. This would make it the second largest squid species in terms of mantle length, after only the colossal squid, and even surpassing the mantle length of the giant squid. However, Nesis added that "because of its narrow body, we conclude that its mass is consistently lower than that of the other large squids".

The type specimen of G. phyllura was collected in Monterey Bay, California and is deposited in the National Museum of Natural History.

meso-bathypelagic