Peraeospinosus peculiaris ( Lang, 1968 ) 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 : 3864-3868

Peraeospinosus peculiaris ( Lang, 1968) n. comb.

( Figures 7 , 8 )

Synonyms. Typhlotanais peculiaris Lang 1968, p 161 –166, Figures 99–101.

Material examined

Holotype: ♀, ZMUC CRU-7748 , R / V Galathea Sta. 192, off Durban, 32 ° 009S, 32 ° 419E, depth 3530 m, 5 February 1951.

Diagnosis

Female. Based on Lang’s (1968) description. Carapace semi-oval. Pereonites 2–5 as long as wide; pereonite 1 relatively long (two-thirds length of carapace). Pleon shorter than carapace, truncated posteriorly. Antennule article 3 three times longer than article 2. Propodus of pereopod 2 length: width ratio about 3.3. One of three distal setae on propodus of pereopod 6 reaching over dactylus, two others not longer than half of dactylus. Pereopods 4–6 unguis without teeth below bifurcated tip. Pereopods 4–6 merus and carpus with strong but rarely distributed spines ventrally. Pleopod endopod with one dorsal seta; clear gap between proximal seta and the remaining ones on pleopod endopod and exopod. Uropod exopod slightly shorter than endopod.

Supplementary description

Female without oostegites ( Figures 7 , 8 ).

Body ( Figure 7A ). Length 8.6 mm. Body about 8.5 times as long as wide.

Cephalothorax. Smooth, rounded, swollen, little longer than wide, rostrum distinctive.

Pereonites. Pereonite 1 two-thirds length of pereonite 2, pereonite 2 and 3 longer than wide, pereonite 4 and 5 as long as wide; pereonite 6 the shortest, half length of pereonite 5.

Pleon. Pleon shorter than carapace; all pleonites similar in size; pleotelson rectangular.

Antennule ( Figure 7B ). Article 1 massive, about one-third longer than articles 2 and 3 combined, with three rod setae marginally and two pinnate setae distally; article 2 one-third length of article 3, with one simple seta and two pinnate setae distally; article 3 with six apical setae.

Antenna ( Figure 7C ). Article 2 a little longer than article 3, both articles without setae; article 4 twice as long as article 5, with two pinnate setae distally; article 5 with one simple seta distally; article 6 very short, with six terminal setae.

Mouthparts. Labrum missing. Mandible ( Figure 7D, E ) typical for genus: robust, molar process well-developed with undulated margins with bunch of delicate and long setae at ‘‘lower’’ margin, lacinia mobilis well-developed, crenulated. Maxillule ( Figure 7F ) typical for genus: with nine apical spiniform setae; two of them fused together; palp missing. Maxilla missing. Labium ( Figure 7G, G 9 ) typical for genus; both lobes poorly separated and hirsute in distal parts; inner lobe with tubercle distally; each external lobe with row of short simple setae and comb of setae along outer margin. Maxilliped missing. Epignath (not drawn) simply tipped (not bifurcated distally).

Cheliped ( Figure 7H ). Basis robust, slightly rounded, 1.6 times longer than wide; merus wedge-shaped with one seta ventrally; carpus with row of seven small rod setae dorsally and two relatively long rod setae ventrally; propodus robust, 1.6 times as long as wide; fixed finger (propodus projection) tipped with a thick spine, with three setae dorsally and two setae ventrally; dactylus slightly curved.

Pereopod 1 ( Figure 8A ). Basis with two rod setae dorsally in proximal part, one short seta ventrally in distal part; ischium short, with one seta; merus subequal to propodus, with one rod seta, one simple and one spiniform seta distally; carpus with three rod setae distally; merus and carpus combined longer than propodus; propodus with one spiniform seta and two rod setae distally, propodus length: width ratio 6.25; dactylus half as long as unguis, with long seta.

Pereopod 2 ( Figure 8B ). Basis little shorter than rest of articles combined, with one simple and one pinnate setae proximally, one rod seta distally, with numerous combs of setae along article; ischium with combs of setae; merus and carpus subequal, merus with one simple and one spiniform seta distally, with numerous combs of setae; carpus with three simple setae and one thick spiniform seta distally, with many combs of robust setae; propodus little shorter than merus and carpus combined, with blunt spiniform seta ventrally and rod seta dorsally, covered with numerous combs of setae; propodus length: width ratio 3.85; dactylus with one simple seta.

Pereopod 3 ( Figure 8C ). Similar to pereopod 2, except ischium with one seta, carpus with extra rod seta dorsally; basis, ischium, and merus without combs of setae.

Pereopod 4 ( Figure 8D ). Basis twice as long as wide, with three rod setae and two pinnate setae along article; ischium with two rod setae ventrally; merus little longer than carpus, with two strong spiniform setae and strong blunt spines ventrally; carpus with two distal hooks, one seta dorsally, and large prickly tubercle surrounded by row of calcified, blunt spines ventrally; propodus, with two spiniform setae ventrally and one long distal seta, one pinnate seta dorsally; dactylus tipped by clearly bifurcated unguis.

Pereopod 5 ( Figure 8E ). Similar to pereopod 4.

Pereopod 6 ( Figure 8F ). Similar to pereopod 5, except propodus tipped by three setae: two strongly serrated short setae (half length of dactylus) and one long setae (longer than dactylus).

Pleopods ( Figure 8G ). All pleopods similar in structure; exopod and endopod with a row of plumose setae on outer margin (length: width ratio of exopod 3.5, of endopod 4.1); clear gaps between the most proximal and other setae at both rami, endopod with one plumose seta on dorsal margin.

Uropod ( Figure 8H ). Both rami uni-articled, exopod little shorter than endopod; endopod with two pinnate setae at the middle, tipped by four simple terminal setae, one rod and two pinnate setae; exopod with short simple middle seta on outer margin, tipped by one strong seta and one minute simple seta.

Distribution

This species is known only from the type locality: off Durban, 32 ° 009S, 32 ° 419E, depth 3530 m ( Lang 1968) ( Figure 25 ).

Remarks

Peraeospinosus peculiaris was described by Lang (1968) based on two specimens, one obtained from the area of Seychelles –Ceylon [5 Sri Lanka] (1 ° 549N, 77 ° 059E) and one from the vicinity of Durban (32 ° 009S, 32 ° 419E, depth 3530 m). The re-examination of fragments and dissected appendages of both specimens held in the Zoological Museum University of Copenhagen revealed that each of those two specimens represent two nominal species .

The description of P. peculiaris ( Lang, 1968) is confusing. Lang (1968, p 161–166) used the specimen from off Durban for describing external characters (body, carapace, pereonites, and pleon), while the description of the appendages was based on the specimen from the Seychelles – Ceylon region. Nevertheless, Lang clearly stated that the Durban specimen (Sta. 192) was the type specimen, and therefore the specimen from Seychelles – Ceylon is considered to be an undescribed species, described here as Peraeospinosus peculiaroides n. sp.

Figures

Figure 7. Peraeospinosus peculiaris (Lang, 1968), holotype female (ZMCU CRU-7748). (A) Dorsal view; (B) antennule; (C) antenna; (D, E) mandibles left and right, respectively; (F) maxillule; (G) labium; (G9) details of labium external lobe; (H) cheliped. Scale bars: 1.0 mm (A); 0.1 mm (B–H).

Figure 8. Peraeospinosus peculiaris (Lang, 1968), holotype female (ZMCU CRU-7748). (A–F) Pereopods 1–6, respectively; (G) pleopod; (H) uropod. 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).