Ommastrephes bartramii (Lesueur 1821)

Ommastrephes bartramii (Lesueur, 1821)

The red ocean squid or neon flying squid, Ommastrephes bartramii, occurs circumglobally in subtropical and temperate waters (Zuev et al., 1976; Okutani, 1980). Nesis (1979c) described its distribution as “bisubtropical.” In the South Pacific Ocean, O. bartramii occurs eastward from New Zealand to 80°E off the coast of Chile (Polezhaev, 1986).

Larval O. bartramii have been reported from summer collections made off the eastern Australian coast between 28°S and 35°46′S, where sea surface temperatures ranged from 26.9° C to 20.6° C (Nesis, 1979a, pers. comm., 1981; Dunning, 1988c). Small juveniles (&g;75 mm ML) were collected over a broader latitudinal range, between 23°57′S and 38°25′S, but in similar water temperatures.

Except for single juveniles caught at the surface at 32°59′S, 158°02′E, southwest of Lord Howe Island, and at 34°23′S, 165°38′E, southwest of Wanganella Bank, no larval or juvenile O. bartramii were present in 65 plankton and scoop-net samples from the central Tasman Sea over a broad area east of 155°E and south of 32°S during the summers of 1981 and 1982 (Dunning, 1988c).

Off the eastern Australian coast west of 155°E, adult O. bartramii were caught in midwater trawls, on jigs, and in surface driftnets between 23°42′S and 43°46′S, where sea surface temperatures varied from 25.7° C to 14.9° C, respectively. Corresponding temperatures at capture depths varied from 25.7° C to 14.9° C. In the central Tasman and southern Coral seas between 155°E and 170°E, this species was caught in summer between 30°S and 45°45′S (the most southerly station sampled), with corresponding sea surface temperatures of 24.7° C and 14.2° C (temperatures at maximum capture depth 23.8°–11.8°C) (Dunning, 1988c).

Nesis's (1979c) conclusion that cold water off the west coast of Tasmania represents a barrier to the westward distribution of Tasman Sea O. bartramii into the Great Australian Bight is supported by subsequent demersal trawl and jig studies in this region. No adult O. bartramii were identified during extensive trawl and jig surveys made in continental shelf waters (<200 m) off the eastern Australian coast (JAMARC, 1987; Dunning, 1988c).

During a January 1982 extensive midwater and demersal trawl survey where bottom depths varied from 132 m to more than 2000 m, O. bartramii was taken only where bottom depth exceeded 600 m. An additional 13 specimens trawled off the New South Wales coast were examined, and all were taken where water depth exceeded 700 m (Dunning, 1988c).

Variation in abundance relative to latitude in mean numbers of O. bartramii caught on jigs in the central Tasman Sea and southern Coral Sea between early December 1981 and late February 1982 is shown in Figure 5. Ommastrephes bartramii was abundant between 32°S and 40°S where sea surface temperatures ranged from 17° C to 24° C. The highest catch in terms of number of squid was obtained at 32°S in waters of 23° C. Further south, catches consisted of fewer squid but with a larger average size (Dunning, 1988c).

Ommastrephes bartramii (Lesueur, 1821)

Loligo Bartramii Lesueur, 1821, p.90, pl.7.

Ommastrephes Bartramii.—Orbigny, 1839, p.347, in Férussac and Orbigny, Loligo pl.2; pl.21, fig.5; Ommastrephes pl.2, figs. 11, 12.—Berry, 1912b, p.298; pl.47; pl.50, figs.4–5; text figs. 7–8.

Ommastrephes Bartrami.—Steenstrup, 1880, p.73, fig.2; p.79, fig.3; p.81.

Stenoteuthis bartrami.—Pfeffer, 1912, p.465; pls.35–36; pl.39, figs. 1, 2.—Sasaki, 1929, p.289, pl.1, fig.8; pl.24, figs. 1–3; text fig.139.

DESCRIPTION.—The mantle is long and slender (width about 20% of length). Anteriorly it is nearly cylindrical, but at the level of the anterior edge of the fins, it begins to taper rapidly and terminates in a blunt point. A median ventral keel extends from the level of the conus forward for about 20% of the mantle length. The free anterior margin of the mantle has no distinct projections. The mantle wall is extremely thick and muscular.

The fins are about 40%–45% of the mantle in length and about 70%–75% of the mantle in width. They are rather sharply angled laterally and have free anterior lobes.

The funnel is very muscular and rather short. The funnel locking-cartilage is complex. The groove has roughly the shape of an inverted T. The dorsal pad of the funnel organ is very large and has an inverted V-shaped appearance. A small anterior papilla can sometimes be detected. The ventral pads are large and oval. A large funnel valve is present. The funnel is fused to the head forward of each locking-cartilage by a muscular bridge.

The head, approximately the same width as the mantle, has large eyes which occupy almost its entire lateral sides. Each eyelid has a large anterior sinus. A nuchal crest with 4 folds on each side is present; the most medial folds embrance the funnel. Posteriorly the folds all converge. A low oblique ridge on the posterior extension of the second fold from the funnel is apparently the “olfactory” organ. A small “window” is situated ventral to each eye, but there is only a slight trace of a dorsal “window.” The funnel groove contains a large foveola at its anterior end. Seven folds are present within the foveola, and 2–4 side pockets are located lateral to it on either side.

The arms are short (30% to 40% of the M.L.) and powerful. Arms I–III all have well-developed aboral swimming keels. In addition, arms I possess accessory lateral keels. Large lateral keels are present on arms IV. All arms have well-developed trabeculate protective membranes. The membranes on the ventral margins of arms I–III are greatly enlarged, but are most extensive on arms III. The elongate trabeculae extend to the margins of the membranes.

The arms have biserial suckers. Arms I–III bear from 50–55 suckers while arms IV (excepting the hectocotylus) have about 65 suckers. The dentition of the suckers is somewhat variable. The basal suckers from arms III have about 16–18 pointed teeth (some teeth have irregular shapes) on the distal three-fourths of the ring; the proximal margin is smooth or finely toothed. By the fifth transverse row of suckers from the base of the arm, the teeth are more regularly shaped and the entire ring is clearly lined with about 28–32 teeth. The largest teeth occur on the distal margin; however, these teeth frequently alternate with smaller teeth. The outer ring is made up of roughly 75 elongate slats; each, with only a few exceptions, extends unbroken from the inner to the outer margin of the ring. The slats on the distal portion of the ring bear small knobs at their bases. At the fourteenth row the proximal portion of the inner ring is smooth, and the distal portion bears about 7 large, pointed teeth that may or may not alternate with very small teeth. The largest suckers of arms IV are just slightly smaller than those of the first arms which, in turn, are slightly smaller than those of arms II and III.

The left arm IV is usually hectocotylized in males, although occasionally the right arm is modified instead. The largest specimen available (303 mm M.L.) is immature and the hectocotylus is probably only partially formed. All specimens available show some signs of hectocotylus formation which begins with the loss of suckers at the extreme tip of the arm. The largest specimen has 27 suckers on the proximal part of the arm which is followed by a suckerless area which would normally carry 7 suckers. Distal to this is a single row of 6 suckers on the dorsal margin, and the remaining portion of the arm lacks suckers. Distal to the proximal series of suckers, the protective membranes do not appear to have trabeculae. It is likely that this is not a completely mature hectocotylus.

The tentacles bear an aboral keel which runs along the tentacular stalk and is continuous with the dorsoaboral keel of the club. Trabeculate protective membranes occur along both margins of the oral face of the tentacular stalk for most of its length; however, the membrane of the dorsal margin is much more extensive. These membranes extend to the tip of the club along the lateral margins. The clubs are expanded and elongate. The suckers of the manus are arranged in 4 longitudinal rows except at the proximal end where they are irregularly aligned and extend onto the tentacular stalk for a short distance. The suckers on the dactylus are arranged in 4 rows which are continuous with those of the manus. The dactylus suckers grade in size from the largest on the ventral margin to the smallest on the dorsal margin. At the tip of the dactylus, there is a pad of 17 smooth-ringed suckers. At the proximal end of the manus, along the ventral margin, is a row of 2–4 smooth-ringed carpal suckers alternating with 2–4 pads. Proximal to this series lie 5–6 toothed suckers.

The suckers of the medial rows on the manus are nearly 3 times the diameter of the marginal suckers. Numerous fingerlike papillae arise from the fleshy outer edges of these medial suckers. These papillae vary in size and thickness and are often joined at their bases in groups of 4–5, each set looking like a human hand. The papillae are also present on the marginal suckers but are located in only 2 tufts, one on each dorsolateral corner with the biggest tuft nearest the margin of the club. Papillae are not present on the dactylus suckers. On 2 of the largest suckers of the manus 123 and 128 slats were counted in the outer ring. These slats have small knobs at their bases.

The inner rings of the largest suckers of the manus have 4 enlarged teeth, one in each quadrant. Occasionally an additional enlarged tooth may be observed. There are generally 7–10 smaller teeth, which may vary considerably in size, in each quadrant between the large teeth. The marginal suckers have about 25–30 teeth with those of the distal border being much larger than those of the proximal border. Generally, minute teeth may be observed alternating with the distal teeth. The suckers of the dactylus have the same dentition as the marginal suckers on the manus.

The buccal membrane has 7 lappets. The buccal connectives attach to the dorsal borders of arms I, II, and IV, and to the ventral borders of arms III.

The animal is speckled with numerous, small, reddish brown chromatophores. The ventral surface of the mantle bears an elongate, sharply delineated, silvery strip that extends from the anterior edge of the mantle posteriorly to the level of the anterior edge of the fins. The ventral surface of the head also has a silvery background that extends down arms IV. The dorsal surface of the mantle and the dorsal midportion of the fins have a deep-purple coloration that terminates very abruptly laterally. The dorsal surface of the head is similarly colored, as are the dorsalmost portions of arms I–III and tentacles. The lateral sides of the head and mantle have a silvery, iridescent layer benath the chromatophores.

Numerous photophores are imbedded in the musculature near the ventral surface of the mantle. These photophores are not visible in preserved specimens unless the skin is removed, and often it is necessary to chemically macerate the muscle tissue. The photophores are small, closely packed, and extremely irregular in shape. Along the ventral midline of the mantle, there is a strip extending from the conus of the pen to nearly the free margin of the mantle in which the number of photophores is reduced. In the posterior quarter of this strip photophores are lacking.

The concentration of photophores is greatest near the free margin of the mantle. This group of photophores extends along the lateral sides of the mantle margin becoming progressively less numerous. There are no photophores dorsally.

An irregular patch of photogenic tissue is situated on either side of the head at the point of attachment of the muscular bands which pass from the ventral surface of the head to the funnel near the locking-cartilages. At least several photophores are located in the integument and connective tissue immediately anterior to the foveola. Unfortunately, in the specimen examined, the integument was stripped away from most of this area; therefore, there may be more photophores in an intact specimen. Another extremely irregular patch of photogenic tissue is situated on the head near the base of each ventral arm. There is also a long band of photogenic tissue that extends from the base of each ventral arm nearly to the arm tip within the base of the lateral keel.

Within the funnel there is a patch of photophores, clustered approximately into a V-shape, that is located above (dorsal to) the dorsal pad of the funnel organ.

With growth, the patches of photophores on the ventral surface of the head increase in size and change somewhat in shape. The specimen described and illustrated here (Plate 6C) has a M.L. of only 210 mm; therefore, the size of the patches on the head, at least, can be expected to be more extensive in mature specimens.

Ommastrephes bartramii (Lesueur, 1821)

Loligo bartramii Lesueur, 1821:90, pl. 7.

Ommastrephes bartramii.—Orbigny, 1835:55.

Sthenoteuthis bartramii.—Verrill, 1887:223.

Ommastrephes caroli Furtado, 1880:5.

Ommastrephes caroli stenodactyla Rancurel, 1976a:81 [the subspecific name, stenobrachium, was also used in the text, but this was in error (Rancurel, 1980, and pers. comm., 1988)].

DIAGNOSIS.—As for genus.

ORIGINAL DESCRIPTION.—Lesueur, 1821:90, pl. 7.

TYPES.—Holotype: Details of size, sex, and collection locality of specimen not given; originally deposited in the Academy of Natural Sciences, Philadelphia, but specimen no longer extant.

Paratypes: None designated.

The neon flying squid (Ommastrephes bartramii), sometimes called the red flying squid, akaika, and red squid is a species of large flying squid in the family Ommastrephidae. They are found in subtropical and temperate oceanic waters globally.

The genus contains bioluminescent species.

Known from seamounts and knolls