Peraeospinosus magnus ( Kudinova-Pasternak, 1990 ) Błażewicz-Paszkowycz, 2005

Błażewicz-Paszkowycz, Magdalena, 2005, Revision of the genus Peraeospinosus Sieg, 1986 (Crustacea: Peracarida: Tanaidacea), Journal of Natural History 39 (45), pp. 3847-3901 : 3861-3863

Peraeospinosus magnus ( Kudinova-Pasternak, 1990) n. comb.

( Figure 6 )

Synonymy. Typhlotanais magnus Kudinova-Pasternak 1990, p 94 –96.

Material examined

Holotype: ♀, MS-9, R / V Akademik Kutchatov; 31 ° 26.79S, 10 ° 029E, depth 4870– 4862 m. Diagnosis

Female. Carapace 1.25 times longer than wide, truncated anteriorly. Pereonites 1, 2, and 4–6 wider than long. Pereonite 1 relatively long (two-thirds length of carapace). Pleon longer than carapace; pleotelson truncated posteriorly. Antennule article 3 three times as long as article 2. Pleopod endopod with two dorsal setae. Uropod rami subequal.

Supplementary description

Female without oostegites, length 6.1 mm ( Figure 6A ).

Body. Body about seven to eight times longer than wide.

Pereonites and pleonites. Pereon 1 is two-thirds as long as carapace and subequal to pereonite 6; pleon longer than carapace; all pleonites similar in size; pleotelson truncated posteriorly.

Antennule ( Figure 6B ). Article 1 a little longer than articles 2 and 3 combined, with three pinnate setae distally and three minute setae along article; article 2 is one-third as long as article 3, with one simple seta distally; article 3 with seven simple apical setae.

Antenna ( Figure 6C ). Article 2 twice as long as article 3, both with short rod seta; article 4 twice as long as article 5, with five setae distally; article 5 with one simple seta distally; article 6 very short, with seven terminal setae.

Mouth parts and pereopods. Missing.

Pleopods ( Figure 6D ). All pleopods similar in structure; endopod with two dorsal (inner) setae, exopod and endopod with a row of plumose setae on outer margin (length: width ratio of exopod 3.75; of endopod 2.9); no clear gap between the most proximal and other setae.

Uropod ( Figure 6E ). Both rami uni-articled, subequal; endopod with one pinnate seta at the middle, tipped by four simple terminal setae and three pinnate setae; exopod with short simple middle seta on outer margin, tipped by strong and minute simple seta.

Distribution

Known only from the type locality ( Figure 25 ).

Remarks

Peraeospinosus magnus is known only from the holotype, a specimen which lacks most appendages. The combination of characters observed in the antennule, antennae, pleopods, and uropods is enough to recognize P. magnus as a valid species. It is the only member of Peraeospinosus with two setae on the inner margin of the pleopods.

Figures

Figure 6. Peraeospinosus magnus (Kudinova-Pasternak, 1990), holotype female (MS-9). (A) Female dorsal view; (B) antennule; (C) antenna; (D) pleopod; (E) uropod. Scale bars: 1.0 mm (A); 0.1 mm (B–E).

Figure 25. Distribution of genus Peraeospinosus based on Beddard (1886a, 1886b), Kudinova-Pasternak (1966, 1969, 1990), Lang (1968), and Shiino (1978).