Joubiniteuthis portieri (Joubin 1916)

Joubiniteuthis portieri (Joubin, 1912)

Chiroteuthis portieri Joubin, 1912, p. 396; 1916, p. 1; 1924, p. 80.—Clarke, 1966, p. 203.

Joubiniteuthis portieri, Berry, 1920, p. 152.—Naef, 1922, p. 299; 1923, pp. 237, 810.—Grimpe, 1925, pp. 97, 103.—Thiele, 1935, p. 977.

Valdemaria danae Joubin, 1931, p. 176; 1933, p. 44.—Clarke, 1966, p. 206.

List of Material

DESCRIPTION.—The mantle is long and slender (Figures 1A, D) ; its walls are heavily invaded with gelatinous tissue. The muscular portion of the mantle terminates in the region of the anterior one-third of the fins. The small fins are thick and gelatinous medially but are thin around the free edges. They are slightly longer than broad and are oval in outline; no free lobes occur (see measurements in Table 1). Posteriorly the fins terminate abruptly. The extremely long, slender tail is slightly longer than the length of the mantle. The needle-like tail tapers gradually to a sharp point; for its full length it is primarily comprised of the elongate conus of the gladius which is covered only by soft, thickened integument.

The gladius (Figure 1B) is an extremely long, thin, tapering rod. The rhachis is free for nearly one-third the length of the gladius. The vane is weakly developed; it folds ventrally from its point of origin, and the edges fuse in the posterior one-third of the gladius to form a long conus.

The funnel extends to the level of the middle of the eyes. Only the short, narrow exhalent tip is free, and the remainder of the funnel is embedded in the soft tissue of the head. The funnel is thick-walled and has a semigelatinous consistency. Two pairs of muscular bridles connect the anterior portion of the funnel to the head. The funnel locking-cartilage is small and oval; it consists of a deep, oval concavity that deepens

posteriorly and undercuts the posterior edge of the cartilage. A membranous flange encircles the cartilage. Both tragus and antitragus are lacking. The bulbous mantle component protrudes conspicuously from the inner surface of the mantle (Figure 2D). The dorsal member of the funnel organ is an inverted U-shaped pad; the limbs are broad and rounded. The surface of the organ has convolutions. A low, median ridge on the organ extends anteriorly as a short, spatulate, apical papilla. The ventral members are small, oval pads (Figure 2F). A funnel valve is present.

The head is elongate and cylindrical; it bears moderate-sized eyes. The finger-like olfactory papillae arise at the back of the head just lateral to the anterior portion of the funnel.

The arms are extraordinarily long, slender, and whiplike. The bases of the arms are broad and robust. The arms taper gradually and terminate in minute, blunt, or conical tips. Arms I–III are nearly subequal and are two to four times longer than the length of the mantle (exclusive of the tail). The fourth arms are relatively short and slender, approximately 80 percent as long as the mantle.

A well-developed web joins the bases of arms I–III: it is not present between arms IV and it is very low between arms III and IV. Protective membranes are very low and weakly developed on all the arms. Near the bases of the arms the membranes are apparently

entirely absent, but minute bumplike trabeculae are present.

Suckers are biserially arranged at the bases of arms I–III, but they increase to four, then to six, often irregularly arranged rows that appear to extend to the tips of the arms (Figure 3A). The closely packed, irregular arrangement of suckers near the arm tips, however, makes it difficult to determine the exact number of rows. The suckers on arms IV originate in two rows, then quickly increase to four rows which remain distinct nearly to the tips of the arms (Figure 3B). The arm suckers are small and extremely numerous. The diameter of the suckers on all arms decreases as the number of rows increases. The medial suckers are one and one-half to two times the diameter of the marginal suckers along most of each arm length. The basal suckers that lie in two rows are large with small apertures; the most proximal few suckers have smooth sucker rings. The next suckers bear small pointed teeth; farther distally the teeth are larger and number between seven to nine on the distal two-thirds of the ring. At the point where the number of sucker rows reaches six, the suckers decrease in size and bear six or seven pointed to truncate teeth on the distal margin (Figures 3C–N, P). The suckers again increase in size toward the middle of the arms.

The tentacles are long and threadlike; the stalks are naked. The club is elongate (about half as long as the mantle length exclusive of the tail) and laterally compressed. The oral face is rounded and no division into dactylus, manus, and carpus occurs. The club is covered with numerous, minute, closely packed suckers that arise proximally in one or two rows, then increase to 5–6 transverse rows; 8–12 rows span the width of the club in its distal two-thirds. The tip of the club appears to be the growing area where new suckers are formed. The distal fifth or sixth of the club is bordered by a distinct protective membrane with no apparent trabeculae. Protective membranes are lacking elsewhere on the club. The suckers have small apertures and smooth rings (Figure 3C).

The buccal membrane has seven lappets. The indistinct buccal connectives are embedded in gelatinous tissue and attach to the dorsal sides of arms I and II and to the ventral sides of arms III and IV. The distal area of the oral face of the buccal membrane bears numerous long, finger-like papillae dorsally that decrease in number and size ventrally. Papillae are lacking on the proximal region of the membrane, particularly

ventrally where only small crenulations occur. The lips are thick and bear many low grooves and folds but lack papillae.

The beaks are illustrated on Figure 2G. The upper beak has a slender, sharply pointed rostrum and a long, triangular hood; the insertion plate of the palatine lamella is long. The rostrum of the lower beak is blunt and triangular; no ridge occurs across the gular lamella.

The radula consists of seven rows of teeth in a transverse series (Figure 2E). The rhachidian tooth has a broad, blunt median cusp and two small, pointed lateral cusps. The first and second lateral teeth have broad, blunt primary cusps that are only slightly smaller than the primary cusp of the rhachidian tooth; small, sharp lateral cusps occur on the first lateral teeth. The third lateral teeth are long, slender, and pointed. Rectangular marginal plaques are present.

Photophores are absent.

The males lack hectocotylization. In the mature male the penis is very large and reaches about the level of the anterior end of the funnel. A spermatophore is illustrated in Figure 4.

The surfaces of the mantle, fins, funnel, head, and arms bear small brown or purplish-brown chromato-phores. The oral surface of the brachial crown, and particularly the buccal region, are pigmented with a dull purple color.

LOCATION OF TYPE.—Oceanographic Museum, Monaco? (not verified).

TYPE-LOCALITY.—29°03′N, 16°08′30″W, in the region of the Salvage Islands.

DISTRIBUTION.—The geographic distribution of all known records of J. portieri is plotted in Figure 5. All specimens were captured in open nets. The type of J. portieri was taken at 0–3500 m; the type of V. danae came from an estimated depth of 500 m; the present specimens came from estimated depths that range from 330 m to 2500 m.

Discussion

COMPARISON OF Joubiniteuthis portieri AND Valdemaria danae.—Joubin’s lengthy descriptions of Joubiniteuthis portieri (1916, 1924) and Valdemaria danae (1931, 1933) give few characters that can be used to separate these forms, and it is difficult to understand why he placed the two species in separate families (his subfamilies). The apparent differences, which Joubin may have considered important, can be easily reconciled. Two distinctive features of Valdemaria, the very elongate tail and the peculiar tentacles, were missing in the badly damaged specimen of Joubiniteuthis portieri. (The original illustrations of V. danae and J. portieri are reproduced in Figure 6). Although Joubin described a funnel valve in V. danae, he was unable to detect one in J. portieri, also undoubtedly due to its deteriorated condition. The lengths of arms I–III differ considerably in the two descriptions. The type of J. portieri has arms three to four times longer than the

length of the mantle, while the type of V. danae has arms about two and one-half times the mantle length. The lengths of arms I–III in our specimens show variation from two to nearly four times greater than the length of the mantle, depending on the condition of the specimen. The differences in the lengths of the arms of Joubin’s specimens clearly are of no significance. The only remaining difference between the two nominal species concerns the number of rows of suckers on arms IV. V. danae is described as having only two rows of suckers on each of these arms with additional, irregularly interspersed suckers (Joubin, 1931). In the subsequent description of V. danae (1933), however, Joubin stated that all of the arms except the hectocotylus have four to six rows. Our examination of the same specimen (Dana 1185 XIII) shows the ventral arms to have a maximum of four rows of suckers. Joubin described six rows of suckers in the midportion of the ventral arms of J. portieri. Specimens that are not in perfect condition, however, generally have suckers that are very irregularly arranged along the twisted, contracted, serpentine arms, and it is difficult to determine the exact number of rows. Poor condition of the specimen also probably accounts for the discrepancy in the small number of rows of suckers reported at the tips of the arms in J. portieri.

We conclude, on the basis of the well-preserved material available and of the type descriptions, that Valdemaria danae is synonymous with Joubiniteuthis portieri. We have been unable to examine the types.

Joubin (1933) described a peculiar S-shaped hectocotylus in Valdemaria danae. We have examined this specimen (Dana 1185 XIII) and an illustration of the modified arm appears on Figures 2A, B. The arm is

unusual, and at first we, too, thought that it could represent a form of hectocotylization. When we examined two other male specimens, one of which was sexually mature, and found that no such modification existed, it became apparent that Joubin’s specimen had an anomalous arm. Probably the arm was injured while the specimen was living and had begun to heal prior to the capture of the squid.

FAMILIAL RELATIONSHIPS.—The peculiarities of Joubiniteuthis clearly confirm that the inclusion of this genus in a separate family is fully warranted. Although the family is distinctive, some evidence for its relationship with other families can be found. Because the buccal connectives attach to the ventral borders of arms IV, the Joubiniteuthidae is aligned with the following families that have the same type of attachment: Onychoteuthidae, Gonatidae, Cycloteuthidae, Thysanoteuthidae, Ctenopterygidae, Octopoteuthidae, Brachioteuthidae, Lepidoteuthidae, Batoteuthidae, Chiroteuthidae, Mastigoteuthidae, Promachoteuthidae, Grimalditeuthidae, and Cranchiidae.

The presence of a conus formed by the ventral fusion of the lateral edges of the vane occurs in the Joubiniteuthidae, Cycloteuthidae, Brachioteuthidae, Lepidoteuthidae, Batoteuthidae, Mastigoteuthidae, Chiroteuthidae, Grimalditeuthidae, and Cranchiidae. (The Promachoteuthidae, although related to these families, apparently lacks a gladius [Roper and Young, 1968].) The oval funnel locking-cartilage more closely relates the Joubiniteuthidae to the Chiroteuthidae, Mastigoteuthidae, and Promachoteuthidae than to any of the other families. The numerous small suckers in many rows on the tentacular clubs are similar to the condition in the Mastigoteuthidae and Promachoteuthidae. The Joubiniteuthidae probably is most closely related to these two families.

Joubiniteuthis portieri, also known as Joubin's squid from the monotypic family Joubiniteuthidae and genus Joubiniteuthis. It is a rare, small squid which occurs in the mesopelagic to bathypelagic zones and which has a worldwide distribution in tropical and subtropical regions. It is a distinctive squid having long arms I-III which have numerous small suckers in six rows. Its biology is little known and it is thought that it stays in the depths of the ocean with its arms outstretched waiting for small animals to ensnare after they have accidentally swum into the arms. This species is named after Louis Joubin, a French zoologist. It is known to reach a mantle length of 9 cm.

It is thought to be the closest relative of the bizarre, famous bigfin squids (genus Magnapinna).

Joubiniteuthis portieri còn được gọi là Mực Joubin, là một loài mực hiếm, nhỏ tìm thấy ở cả Đại Tây Dương, Thái Bình Dương và trong trường hợp hiếm hoi, Ấn Độ Dương. Loài này được đặt theo tên Louis Joubin, một nhà động vật học Pháp. Được biết, nó có áo đạt chiều dài 9 cm.