Peraeospinosus Sieg, 1986
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publication ID |
https://doi.org/ 10.1080/00222930500450879 |
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persistent identifier |
https://treatment.plazi.org/id/03A787E0-FFA1-FFBA-FE1D-FF64FBFB45C1 |
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treatment provided by |
Felipe |
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scientific name |
Peraeospinosus Sieg, 1986 |
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Peraeospinosus Sieg, 1986 View in CoL
Diagnosis
Female. Body robust, elongated, usually 5.6–10 times as long as wide, preserved specimens are often stiff and straight (stick-like). Some of pereonites 1–5 with collar-like grooves, usually anteriorly or posteriorly. Carapace usually oval or rounded, rarely narrow, rostrum well-developed. Dorsal margin of cheliped carpus with row of minute setae. Labrum hoodshaped, with upper part covered with needle-like setae. Molar process with row of setae on lower margin of crushing edge. Maxillule with nine spiniform setae distally, two semi-fused (10th short seta centrally usually not observable). Labium external lobes with row of minute setae on edges. Maxilliped bases wide, heart-shaped, endites with two small flat setae (tubercles) on distal margins. Epignath sharply tipped, often bifurcated. Pereopods 1– 3 walking type. Pereopods 4–6 clinging type. Distal seta on propodus of pereopods 4 and 5 longer than unguis; prickly tubercles on pereopods 4–6, surrounded by blunt, calcified spines; unguis of pereopods 4–6 bifurcated. Exopod of pleopods semi-elliptical. Uropod rami usually uni-articled, equal or subequal. Uropod exopod tipped by diminutive and robust seta (at basis almost as wide as exopod).
Male. Only the male of P. subtigaleatus n. sp. is known. Swimming type. Pereonites less developed than in females, pleonites more so. Pleon subequal in length to pereon. Pleotelson elongated, with well-developed caudal process. Antennule and antenna sevenarticled; antennule articles 4–6 with multiple aesthetascs. Mouthparts reduced. Maxilliped bases fused, forming heart-shaped plate; maxilliped endite lobe-shaped, with two setae and two flat setae (tubercles) distally. Cheliped with row of setae near insertion of dactylus. Pereopods long and slender (walking type). Pleopods well-developed. Uropod exopod three-articled, endopod two-articled.
Type species. Typhlotanais pushkini Tzareva, 1982 .
Distribution
Members of newly defined Peraeospinosus have so far been recorded from the Pacific Ocean (off Alaska, Kurile-Kamchatka Trench, Japan Trench), the Indian Ocean ( Sri Lanka, off Dunbar), the Atlantic (off Argentina), and the Southern Ocean (Kerguelen Island, Bransfield Strait, South Shetlands, Ross Sea). The genus is widely distributed in abyssal and hadal depths. Only in the Antarctic has it been found on the continental shelf at 300–400 m ( Figure 25 View Figure 25 ).
Remarks
Five species Peraeospinosus (5 Typhlotanais ) kerguelenensis (Beddard, 1886) , P. (5 T.) magnificus ( Kudinova-Pasternak, 1969) , P. (5 T.) magnus ( Kudinova-Pasternak, 1990) , P. (5 T.) peculiaris ( Lang, 1968) , and P. (5 T.) rectus (Kudinova-Pasternak, 1968) are now placed in the genus Pereospinosus.
Pereospinosus (Sieg, 1986), Typhlotanais (G. O. Sars, 1882) , and Typhlotananoides (Sieg, 1983) are the only typhlotanaid members that have pereopods 4–6 adapted for clinging in the tubes. Members of the newly defined Pereospinosus share a few specific characters which allow them to be distinguished from the other typhlotanaids (see Table I). The third, monotypic, genus Typhlotanaoides has a hook-shaped unguis on pereopods 4–6 that is usually simple or bifurcate in the members of the genus Typhlotanais sensu lato.
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