Peraeospinosus magnificus ( Kudinova-Pasternak, 1969 ) 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 : 3857-3861

Peraeospinosus magnificus ( Kudinova-Pasternak, 1969) n. comb.

( Figures 4 , 5 )

Synonymy. Typhlotanais magnificus Kudinova-Pasternak 1969, p 1737 –1738; 1970, p 349– 351; 1973, p 153; 1993, p 141–142.

Material examined

Holotype: ♀, MS-950, Vitjaz Sta. 5620, 44 ° 069N, 155 ° 549E, depth 4895 m.

Diagnosis

Female. Carapace 1.3 times as long as wide, oval; pereonites 1–5 longer than wide; pereonite 1 relatively long (three-quarters length of carapace). Pereonite 6 one-third as long as carapace. Pereonites 1–3 narrowing in middle. Antennule article 3 three times as long as article 2. Propodus of pereopod 2 length: width ratio 5.5. Unguis of pereopods 4–6 without middle teeth. Merus and carpus of pereopods 4–6 with weak, blunt spines ventrally.

Propodus of pereopod 6 with one long seta distally. Pleopod endopod with one dorsal seta and six setae in distal part.

Supplementary description

Female, length 5.8 mm from rostrum to pleon 5 ( Figure 4A ).

Body. Body about eight times longer than wide.

Cephalothorax. Smooth, oval, one-quarter longer than wide; rostrum distinctivly rounded.

Pereonites. Pereonites 1–5 longer than wide, with only slightly rounded corners; pereonite 6 three times wider than long and a little narrower than pereon 5, one-quarter as long as carapace.

Pleon. All pleonites similar in size. Pleotelson missing.

Antennule ( Figure 4B ). Article 1 narrow, four times as long as wide, with group of pinnate setae distally and two short rod setae along article; article 2 three times as long as article 3, with one rod seta and one pinnate seta distally; article 3 with six sharply tipped setae (three long and three short).

Antenna ( Figure 4C ). Article 2 a little longer than article 3; both articles naked; article 4 is 1.6 times longer than article 5, with three pinnate and two rod setae distally; article 5 with one simple seta distally; article 6 very short, with six terminal setae (four long and two short).

Mouthparts. Labrum ( Figure 4D ) typical for genus, covered by numerous short needle-like setae. Mandible ( Figure 4E ) robust, molar process well-developed, crushing edge covered by numerous tubercles or spines, with bunch of short spiniform setae ( Figure 4E 9 ’). Maxillule ( Figure 4F ) typical for genus; endite one-quarter times longer than palp, with nine apical spiniform setae (two of them fused together); palp with two apical setae (one shorter than other). Maxilla, labium, maxilliped, and cheliped missing.

Pereopod 1 ( Figure 5A ). Basis with one pinnate seta in proximal part and three rod setae along article; ischium with one rod seta; merus subequal to propodus, with two rod setae distally; carpus with five rod setae distally; propodus five times as long as wide, with two rod setae dorsally and minute spiniform seta ventrally; dactylus as long as half unguis, with short seta (not longer than dactylus).

Pereopod 2 ( Figure 5B ). Basis little shorter than merus, carpus and propodus combined; with two rod setae in the middle of article and one pinnate proximal seta; ischium with rod seta; merus little longer than carpus, with two rod setae and two spiniform setae; carpus with five rod setae and one spiniform seta distally; propodus little shorter than merus and carpus combined, with one spiniform seta ventrally and one rod seta and one trifurcate seta dorsally; propodus length: width ratio 5.5; dactylus with one simple distal seta. Unguis twice as long as dactylus.

Pereopod 3 ( Figure 5C, C 9 ). Similar to pereopod 2 but merus with one trifurcate and one spiniform seta only; carpus with two trifurcate and three rod setae ( Figure 5C 9 ).

Pereopod 4 ( Figure 5D ). Basis 2.6 times as long as wide, with two pinnate setae and one rod seta dorsally and two pinnate setae ventrally; ischium with one seta; merus with two spiniform setae and combs of blunt teeth ventrally; carpus with two distal hooks and large, prickly tubercle surrounded by row of blunt, calcified spines; propodus with two spiniform setae ventrally, pinnate seta dorsally and distal seta reaching over unguis; dactylus tipped by bifurcated unguis.

Pereopod 5 ( Figure 5E ). Similar to pereopod 4.

Pereopod 6. Missing in holotype. According to Kudinova-Pasternak (1970, p 350, Figure 5 ) propodus of pereopod 6 with one long seta distally.

Pleopods ( Figure 5F ). All pleopods similar in structure; endopod (length: width ratio 2.6) with one seta on dorsal margin; six plumose setae in distal part and one plumose seta proximally; large gap between distal and proximal setae; exopod with a row of 18 plumose setae on outer margin (length: width 3.9); relatively short gap between the most proximal and the other setae.

Uropod. Missing.

Distribution

The species has a discontinuous distribution: in the North Pacific (off California, off Japan and Alaska), the South Atlantic ( Argentina), and the West Antarctic (Bransfield Strait) ( Figure 25 ). Depth range: 1170–5225 m.

Remarks

The only specimen of P. magnificus available for the study lacks some of the appendages and pleotelson. The remaining appendages and the figures presented in Kudinova- Pasternak (1970, p 350) are enough for recognition and placement of the present species in Peraeospinosus . Peraeospinosus magnificus most resembles P. emergensis n. sp. and P. exiliremis n. sp. having pereonites 1–3 slightly narrowed in the middle and antennule article 3 three times longer than article 2. However, it has a much more elongated carapace than the two last species. Also, only P. magnificus has six, fully developed setae on the lower margin of the pleopod endopod, while P. emergensis has 15 setae on lower margin of the pleopod endopod and P. exiliremis has a few short simple setae there.

Figures

Figure 4. Peraeospinosus magnificus (Kudinova-Pasternak, 1969), holotype female (MS-950). (A) Female dorsal view; (B) antennule; (C) antenna; (D) labrum; (E) mandible right; (E9) molar process; (F) maxillule. Scale bars: 1.0 mm (A); 0.1 mm (B–F).

Figure 5. Peraeospinosus magnificus (Kudinova-Pasternak, 1969), holotype female (MS-950). (A–E) Pereopods 1– 5, respectively; (C9) details of pereopod 3 carpus; (F) pleopod. Scale bars: 0.1 mm.

Figure 9. Peraeospinosus pushkini (Tzareva, 1982), female. (A) Dorsal view; (B) lateral view; (C) cephalon ventral view; (D) pleopod. Scale bars: 1.0 mm (A, B); 0.1 mm (C, D).

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