Revision of the genus Peraeospinosus Sieg, 1986 (Crustacea: Peracarida: Tanaidacea) Author Błażewicz-Paszkowycz, Magdalena text Journal of Natural History 2005 2006-01-30 39 45 3847 3901 http://dx.doi.org/10.1080/00222930500450879 journal article 10.1080/00222930500450879 1464-5262 5221058 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 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). 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.