Peraeospinosus rectus ( Kudinova-Pasternak, 1966 ) Błażewicz-Paszkowycz, 2005
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publication ID |
https://doi.org/ 10.1080/00222930500450879 |
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persistent identifier |
https://treatment.plazi.org/id/03A787E0-FFB9-FF9F-FED1-FDFAFDC140E9 |
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treatment provided by |
Felipe |
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scientific name |
Peraeospinosus rectus ( Kudinova-Pasternak, 1966 ) |
| status |
comb. nov. |
Peraeospinosus rectus ( Kudinova-Pasternak, 1966) View in CoL n. comb.
( Figures 12–14 View Figure 12 View Figure 13 View Figure 14 )
Synonymy. Typhlotanais rectus Kudinova-Pasternak 1966, p 525 ; 1970, p 349, 379; 1975, p 211–212, 217; 1976, p 121; 1977, p 121.
Material examined
Holotype: ♀, MS-944, Vitjaz Sta. 4074, 40 ° 19.79N, 175 ° 45.39E, depth 6065 m.
Diagnosis
Female. Carapace rounded, as long as wide, a little swollen. Pereonites 2 and 3 as wide as long. Pereonite 1 relatively long (two-thirds length of carapace). Pleon little longer than carapace, truncated posteriorly. Antennule article 3 twice as long as article 2. Propodus of pereopod 2 length: width ratio about 4.6. One distal seta on propodus of pereopod 6 reaching over the unguis. Pleopod endopod elongated (over four times as long as wide). Pleopod endopod with one dorsal seta. Uropod exopod slightly shorter than endopod.
Supplementary description
Female without oostegites, length 5.8 mm ( Figures 12–14 View Figure 12 View Figure 13 View Figure 14 ).
Body ( Figure 12A, B View Figure 12 ). Body about 5.5 times longer than wide.
Cephalothorax. Rounded, only slightly longer than wide, twice as long as pereonite 6; rostrum rounded.
Pereonites. Pereonites 1, 5, and 6 wider than long, pereonites 2 and 3 as long as wide, pereonite 4 longer than wide. Pereonites 1–3 with characteristic grooves (one on pereonites 1 and 3 and two on pereonite 2).
Pleon. Pleon as long as carapace. All pleonites similar in size; pleotelson rectangular.
Antennule ( Figure 13A View Figure 13 ). Article 1 massive, about three times as long as wide and a little longer than articles 2 and 3 combined, with group of pinnate setae at middle, and one simple seta distally; article 2 with two pinnate setae distally; article 3 with six simple apical setae (four long and two short).
Antenna ( Figure 13B View Figure 13 ). Article 2 twice as long as article 3, article 2 with short seta; article 4 twice as long as article 5, with one simple seta and two pinnate setae distally; article 5 with one long simple setae distally; article 6 with five terminal setae.
Mouthparts. Labrum missing. Mandible ( Figure 13C View Figure 13 ) typical for genus: robust, molar process well-developed with strongly undulated margins and short setae at ‘‘lower’’ margin; lacinia mobilis well-developed, crenulated. Maxillule ( Figure 13D View Figure 13 ) typical for genus: with nine apical spiniform setae; two of them fused together; palp lost during dissection. Maxilla semi-oval ( Figure 13E View Figure 13 ). Labium ( Figure 13F View Figure 13 ) typical for genus; both lobes poorly separated and hirsute in distal parts; inner lobe with tubercle distally; each ‘‘accessory lobe’’ with row of short simple setae and comb of setae along outer margin.
Maxilliped ( Figure 13G View Figure 13 ). Basis (typical for genus) fused in heart-shaped plate; endite with two rod setae and two flat setae (tubercles) distally; palp article 1 unarmed, article 2 wedgeshaped, with two weakly serrated and one strongly serrated setae on inner margin and one minute seta on outer margin; article 3 trapezoidal, with four weakly serrated setae on inner margin; article 4 slender, with one simple seta on outer margin and five weakly serrated distal setae. Epignath ( Figure 10H View Figure 10 ) simply tipped (not bifurcated distally).
Cheliped ( Figure 14A View Figure 14 ). Basis robust, slightly rounded, 1.5 times as long as wide; merus wedge-shaped with one rod seta ventrally; carpus with row of six small rod setae dorsally and two short rod setae ventrally; propodus robust, 1.5 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 with one rod seta dorsally and two spines ventrally.
Pereopod 1 ( Figure 14B View Figure 14 ). Basis with one pinnate seta in proximal part and four rod setae along article; ischium with one rod seta; merus subequal to propodus, with three 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 subequal to unguis, with one seta not longer than unguis.
Pereopod 2 ( Figure 14C View Figure 14 ). Basis a little shorter than merus, carpus, and propodus combined, with two rod and one pinnate seta; ischium naked; merus a little longer than carpus, with two setae and one spiniform setae distally; carpus with three spiniform, one simple, and one tubercle distally; propodus a little shorter than merus and carpus combined, with spiniform seta ventrally and two rod setae dorsally; propodus length: width ratio 5.6; unguis twice as long as dactylus.
Pereopod 3 ( Figure 14D View Figure 14 ). Similar to pereopod 2 but carpus with some combs of strongly calcified, blunt setae.
Pereopod 4 ( Figure 14E View Figure 14 ). Basis 2.6 times as long as wide, with pinnate setae and one rod seta along article; ischium with one seta; merus ventral margin with spiniform setae and combs of blunt teeth; carpus with two distal hooks and large, prickly tubercle surrounded by row of blunt, strongly 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 14F View Figure 14 ). Similar to pereopod 4 except basis with only two pinnate setae, ischium with two setae, merus with two additional spiniform setae distally.
Pereopod 6 ( Figure 14G View Figure 14 ). Similar to pereopod 5, but propodus with three distal setae (one long and two short).
Pleopods ( Figure 12C View Figure 12 ). All pleopods similar in structure; exopod with row of 16, and endopod with row of 10 plumose setae on outer margin (length: width ratio of exopod 3.1; of endopod 3.4); most proximal seta on exopod, as well as on endopod, is separated from remainder by a gap; one plumose seta on inner margin of endopod.
Uropod ( Figure 14H View Figure 14 ). Exopod with one article. Endopod with suture at place of fusion of two articles; endopod clearly longer than exopod; endopod with two pinnate setae at the middle, tipped by four simple terminal setae and three pinnate setae; exopod with short simple seta in proximal part of outer margin, tipped by strong and minute simple setae.
Distribution
The species has two centres of distribution: Pacific Ocean (Kuryl-Kamchatka Trench, Japan Trench) and West Antarctic ( Figure 25 View Figure 25 ). Depth range 4664–7370 m.
Remarks
Peraeospinosus rectus can be distinguished from the other members of the genus by the presence of strong, blunt, and well-calcified spines on the merus and carpus of pereopods 4–6. Similar spines can be observed in P. exiliremis , which has also other distinguishing characters such as pleon narrower than pereonite, weakly developed pleopods, and uropod exopod little longer than endopod.
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