Pterygioteuthis gemmata Chun 1908

Pterygioteuthis gemmata Chun, Fischer, 1908

Pterygioteuthis gemmata Chun, 1908, p.87; 1910 p.108, pl.13, fig.3; pl.14, figs.4, 5, 9; pl.15, figs.2, 3, 6–12; pl.16, figs. 1, 2, 5, 7–19.—Pfeffer, 1912, p. 194.—Thiele, 1921.—Voss, 1967.

DESCRIPTION.—The mantle is cylindrical anteriorly, but conical posteriorly. The mantle wall is thick and muscular. The pen extends posterior to the fins and terminates in a sharp point. The free margin of the mantle project distinctly in the nuchal region and at the mantle locking-cartilages.

Each fin is large and nearly circular in outline and has broad, free anterior and posterior lobes. The fin length is about 40–50% of the mantle length, and the combined width is about 70–80% of the mantle length.

The funnel is moderate in size, reaching to the level of the midpoint of the eyes. Each funnel locking-cartilages bears a straight median groove. The dorsal portion of funnel organ is an inverted V-shaped pad with a small anterior papilla and a low ridge on each lateral arm. The ventral pads are roughly oval in shape. A large funnel valve is present.

The head is large and has enormous eyes which occupy the entire lateral portions of the head. The eyelid has only a slight indication of an anterior sinus. An “olfactory” papilla is present at the posteroventral edge of each eye as a triangular flap which is swollen at the tip. The olfactory nerve passes along the posterior edge of the flap.

The arms are short and robust. The arm formula is 3>4=2>1. Extremely well-developed trabeculate protective membranes are present on the ventral borders of arms I–III and very weakly developed ones are present on the dorsal borders. Arms IV in females have low, fleshy, protective membranes that are particularly thick near the bases of the arms. Large aboral keels are present on arms I–III, but are best developed on arms III. Arms IV have large lateral keels. The arms have biserial armature consisting mostly of suckers, but with 3–7 hooks on the midportion of the ventral row of each arm I–III. Generally there are 2–4 hooks on each arm I, 4–5 on each arm II, and 5–7 on each arm III, although the maximum range is slightly greater than this (Figure 7). The hooks are considerably larger in males. The suckers of arms IV are much smaller than those of the other arms. The proximal suckers are very small but are gradually larger in size over the first two thirds of the arm, then are progressively smaller to the tip. The larger suckers on all arms possess approximately 6–8 long, slender, truncate teeth on the distal margin of the inner chitinous rings. The hooks are low with broad bases and possess a rather large but irregular secondary cusp beneath the primary one. No remnant of the sucker aperture remains.

The left arm IV of the male is hectocotylized. It bears 2 large fleshy longitudinal ridges (the distal one is somewhat bilobed) between which is located a pocket with pleated lateral sides that contains a toothed plate. The dentition of this plate is slightly variable, but usually has a proximal portion with 5 cusps, then a large single cusp, and a distal set of 2–3 cusps. The distal one-third of the hectocotylus bears low, protective membranes which embrace small, paired suckers in the last 15–20% of the arm. These suckers are fragile and easily lost during capture and preservation. A large lateral keel is present along the length of the arm.

The tentacles are short and the tentacular stalks are naked. The club is only slightly expanded, and possesses moderately developed trabeculate protective membranes; the dorsal membrane is slightly the larger. A distinct keel is lacking. Each carpal cluster consists typically of 3 suckers and 3 pads; occasionally only 2 suckers may be present. Suckers on the manus and dactylus are in 4 rows. The suckers, in a tranverse series on the manus, grade in size from the largest dorsally to the smallest ventrally. The suckers of the ventral row are roughly half the diameter of those of the dorsal row. The suckers of the dactylus are small and equal in size in a transverse series. Dentition of the inner chitinous ring of each of the club suckers consists of approximately 10–14 short, slender, pointed teeth on the distal margin. The proximal margin is smooth or slightly knobby.

The buccal membrane is very long, purple, and has 8 lappets. The inner lining of the membrane is produced into numerous, pale, globular papillae. The primary buccal membrane connectives attach to the dorsal borders of arms I, II, and IV, and to the ventral border of arms III. Secondary connectives attach to the ventral borders of arms I and II.

Each eye possesses 14 photophores on the surface of the bulbus. On the anterior margin of the eye there is a series of 3 large photophores followed posteriorly by a slightly smaller series of 4 photophores, the third of which has a distinctly different structure. Just posterior to the lens is a rather large, single photophore. Along the ventral medial margin of the eye are 2 large well-separated light organs and a more anterior medial series of 4 very small light organs. Most light organs on the eyes are spectacular even in preservation, reflecting any color of the rainbow depending on the angle of incident light. Each tentacle contains 4 light organs buried deep in the aboral tissue of the stalk. One of these photophores lies beside the carpal cluster; 2 lie close together about one-third of the tentacle length from its proximal end, and the other organ lies at the base of the tentacle. Several light organs of various sizes lie within the mantle cavity. A large photophore lies on either side of the rectum. A medium-size photophore lies in the midline on the viscera between the bases of the gills, while 2 very large ones lie just posterior to the branchial hearts. Farther posteriorly on the midline, beginning at approximately the level of the midpoint of the fins, there is a series of 3 small photophores of which the anterior 2 are sometimes completely divided into paired organs; however, more often the organs are simply bilobed. The most posterior organ lies near the tip of the pen approximately at the level of the most posterior point on the fins.

Large, paired nidamental glands are present. Only the right oviduct, which has a well-developed oviducal gland, is present.

The body, head, and arms are covered by large, reddish brown chromatophores. There are distinct silvery iridescent areas on the body and head, although these are rendered nearly invisible by preservation. The sides of the mantle anterior to the fins seem to have been silvery in life although overlain by chromatophores. Similar iridescent spots are present on the posterior-dorsal margin of the head, the posterior-ventral corners of the head, anterior-dorsal corners of the eyes, and the bases of arms II, III and IV and the tentacles.

TYPE LOCALITY.—South Atlantic Ocean.

LOCATION OF TYPE.—Berlin Museum.

Pterygioteuthis gemmata Chun, 1908

ORIGINAL REFERENCE.—Pterygioteuthis gemmata Chun, 1908:87.

DEPOSITION OF TYPES.—Holotype: ZMB, sex and size undetermined, S.S. Valdivia, “South Atlantic Ocean,” condition unknown.

Paratypes: Undetermined.

GEOGRAPHICAL DISTRIBUTION.—South Atlantic (Nesis, 1974); North Atlantic (Clarke and Lu, 1974; Lu and Clarke, 1975b; Cairns, 1976; Lu and Roper, 1979); South Pacific (Riddell, 1985; Polezhaev, 1986); eastern North Pacific (Young, 1972); Indian Ocean (Chun, 1910; Voss, 1967).

COMMENTS.—This species has not been recorded from the Mediterranean Sea (Mangold and Boletzky, 1988).

Pterygioteuthis gemmata is a species of squid in the family Pyroteuthidae.

芽翼魷（学名：Pterygioteuthis gemmata）为火魷科翼魷屬下的一个种。

circum-(sub)tropical

mesopelagic

Known from seamounts and knolls