Peraeospinosus kerguelenensis (Beddard, 1886) 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 : 3851-3857

publication ID	https://doi.org/ 10.1080/00222930500450879
persistent identifier	https://treatment.plazi.org/id/03A787E0-FFA0-FFB5-FEED-FAC3FD8247E8
treatment provided by	Felipe
scientific name	Peraeospinosus kerguelenensis (Beddard, 1886)
status	comb. nov.

Treatment

Peraeospinosus kerguelenensis (Beddard, 1886) View in CoL n. comb.

( Figures 1–3 View Figure 1 View Figure 2 View Figure 3 )

Synonymy. Typhlotanais kerguelenensis Beddard 1886a, p 117 ; 1886b, p 121–122, Plate 16 Figures 1–3 View Figure 1 View Figure 2 View Figure 3 ; Shiino 1978, p 80–85.

Material examined

Kerguelen Island : syntype ♀ on slide, MHM 1889.4.27.105, Challenger 1873–76, Sta. 149H, 48 ° 459S, 69 ° 149E, depth 231 m. 3♀♀, 1♀ prepared on slides, MNHN Ta 316, Marion-Dufresne 04, Sta. G 81/ BB193 , 48 ° 57.69S, 69 ° 38.09’E GoogleMaps , depth 230 m. 2♀♀, MNHN

Ta 306, Marion-Dufresne 04, Sta. H 84/ BB201 , 49 ° 08.39S, 69 ° 56.59E, depth 50 m. 3♀♀ GoogleMaps , MNHN Ta 199, Gulf of Morbihan, Sta. SMK 20 View Materials 12/I, depth 42 m.

Diagnosis

Female. Carapace rounded, as long as wide, swollen. Pereonites 2 and 3 wider than long; pereonite 1 relatively short (one-third carapace length). Pleon longer than carapace, pleotelson truncated posteriorly. Antennule article 3 three times as long as article 2. Maxilliped article 2 with strongly serrated seta. Propodus of pereopod 2 length: width ratio about 6. All distal setae on propodus of pereopod 6 as long as dactylus. Pereopods 4–6 merus and carpus with weak and numerous spines ventrally. Pereopods 4–6 unguis with two blunt teeth below bifurcated tip. Pleopod endopod with one dorsal seta. Uropod exopod slightly shorter than endopod.

Supplementary description

Female without oostegites ( Figures 1–3 View Figure 1 View Figure 2 View Figure 3 ).

Body ( Figure 1A, B View Figure 1 ). Length 4.6 mm. Body about six to seven times as long as wide.

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

Pereonites. Pereonites 1–3 and 5–6 wider than long; pereon 1 and 6 shortest, one-third as long as carapace; pereon 4 longest; ring-like grooves dividing segments into two (pereonites 1 and 4–6) or three (pereonites 2 and 3) subequal parts.

Pleon. Pleomeres and pleotelson combined longer than carapace; all pleonites similar in size; pleotelson truncated posteriorly.

Antennule ( Figure 2A View Figure 2 ). Article 1 massive, about one-third longer than articles 2 and 3 combined, with three groups of simple and pinnate setae; article 2 one-third as long as article 3, with one simple seta; article 3 with seven simple and one pinnate apical setae.

Antenna ( Figure 2B View Figure 2 ). Article 2 twice as long as article 3, with one simple seta; article 4 less than twice as long as article 5, with three minute rod setae and two pinnate setae distally; article 5 with one simple seta distally; article 6 very short, with seven terminal setae.

Mouthparts. Labrum ( Figure 2C View Figure 2 ) hood-shaped, covered by numerous short needle-like setae. Mandible ( Figure 2D, E View Figure 2 ) robust, molar process well-developed with undulated but spineless margins, bunch of delicate setae at ‘‘lower’’ margin ( Figure 2E View Figure 2 9 View Figure 9 ), lacinia mobilis well-developed, crenulated. Maxillule ( Figure 2F View Figure 2 ) endite as long as palp, with nine apical spiniform setae; two of them are fused together; palp lost during dissection. Maxilla lost during dissection. Both lobes of labium ( Figure 2G View Figure 2 ) 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 2H View Figure 2 ). Basis (typical for genus) fused in heart-shaped plate; endite with two simple setae and two flat setae (tubercles) distally; palp article 1 unarmed, article 2 wedge-shaped, 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.

Cheliped ( Figure 3A View Figure 3 ). Basis robust, slightly rounded, 1.75 times as long as wide; merus wedge-shaped, with one rod seta; carpus with row of six small rod setae dorsally and two relatively long rod setae ventrally; propodus with distal seta on inner side; fixed finger (propodus projection) tipped with a strong spine, with two to three teeth and three rod setae dorsally and two setae ventrally; one seta near insertion of dactylus; dactylus slightly curved, with two strong spiniform setae ventrally and one short rod seta proximally on dorsal margin.

Pereopod 1 ( Figure 3B View Figure 3 ). Slender (walking type); basis with two pinnate seta on proximal part only and short setae along article; ischium short with one seta; merus subequal to propodus, with two setae distally; carpus with three simple and one rod setae; merus and carpus combined longer than propodus; propodus with one simple and two rod setae distally, propodus length: width ratio 5.75; dactylus half unguis length, with long seta.

Pereopod 2 ( Figure 3C, C View Figure 3 9 View Figure 9 , C 0). Slender (walking type); basis little longer than rest of articles combined, with minute setae along article and two pinnate setae proximally; ischium with simple seta; merus and carpus subequal, each with combs of spines; merus with two simple setae and thick spiniform seta distally; carpus with two spiniform setae, two trifurcated and one blunt spine distally ( Figure 3C View Figure 3 9 View Figure 9 ); propodus as long as merus and carpus combined, with blunt spiniform seta ventrally and thick rod seta dorsally ( Figure 3C View Figure 3 0); propodus length: width ratio 4.65; dactylus with one simple seta. Unguis subequal dactylus.

Pereopod 3 ( Figure 3D View Figure 3 ). Similar to pereopod 2 but ischium with two setae, carpus with three extra spiniform setae; propodus with one simple, one spiniform, and one rod seta distally.

Pereopod 4 ( Figure 3E View Figure 3 ). Clinging type; basis twice as long as wide, with two simple and two pinnate setae; ischium with two setae; merus subequal to carpus, with two strong spiniform setae on ventral margin and combs of blunt spines; carpus with two distal hooks, one seta dorsally and large tubercle covered by little spines and surrounded by row of calcified ( Figure 3E View Figure 3 9 View Figure 9 ), blunt spines ventrally; propodus, with two spiniform setae ventrally and distal seta twice as long as propodus and dactylus combined length; dactylus tipped by weakly bifurcated unguis; two teeth on ventral margin.

Pereopod 5 ( Figure 3F View Figure 3 ). Similar to pereopod 4.

Pereopod 6 ( Figure 3G View Figure 3 ). Similar to pereopod 5; propodus tipped by three terminal setae as long as dactylus (two coarsely, one finely serrated).

Pleopods ( Figure 1D View Figure 1 ). All pleopods similar in structure; exopod and endopod with a row of plumose setae on outer margin (length: width ratio of both exopod and endopod 3.0); no gaps between the most proximal and other setae.

Uropod ( Figure 3H View Figure 3 ). Both rami uni-articled, exopod little shorter than endopod; endopod with two pinnate setae at middle, tipped by four simple terminal setae (one very short) and two pinnate setae; exopod with short simple middle seta on outer margin, tipped by strong and minute simple setae.

Distribution

Peraeospinosus kerguelenensis View in CoL is known from the region of the Kerguelen Islands (Southern Ocean) ( Figure 25 View Figure 25 ) where it was collected at depths from 17 to 1390 m ( Beddard 1886a; Shiino 1978).

Remarks

Peraeospinosus kerguelenensis View in CoL was originally described as Typhlotanais kerguelenensis View in CoL from Christmas Harbour (Kerguelen Island) (48 ° 459S–69 ° 149E) at 231 m depth. The only specimen available for study (syntype NHM 1889.4.27.105, body length about 4.6 mm, given as up to 3 mm by Beddard 1886a) mounted in Canada balsam. The condition of the specimen is poor but some of the characters can be easily observed: uropod rami, setation of the carpal cheliped, and the setation of the pereopods. These characters unambiguously place the species in the genus Peraeospinosus View in CoL . The other specimen labelled as syntype (NHM 1889.4.15.104; slide in Canada balsam, depth 3731 m, Mid North Pacific: 36 ° 109N, 178˚09E; Beddard 1886b) without doubt does not represent Peraeospinosus kerguelenensis View in CoL , or another species of Pereospinosus.

Peraeospinosus kerguelenensis View in CoL can be distinguished from the other members of Peraeospinosus View in CoL by the relatively long pleon that is slightly longer than the carapace. Also, Peraeospinosus magnus ( Kudinova-Pasternak 1990) View in CoL also has a pleon slightly longer than the carapace but its carapace is long and narrow (length: width ratio 1. 24) which distinguishes it from the former species. The carapace of P. kerguelenensis View in CoL is round (length: width ratio 0.94) and resembles that of P. emergensis View in CoL n. sp., but the last species, unlike P. kerguelenensis View in CoL , has pereonites 2–4 longer than wide. The uropod exopod slightly shorter than the endopod is a character shared by P. kerguelenensis View in CoL , P. rectus ( Kudinova-Pasternak, 1966) View in CoL , P. peculiaris ( Lang, 1968) View in CoL , and P. peculiaroides View in CoL n. sp. Each of the last three species, however, has one seta on the propodus of pereopod 6 reaching far over the unguis, while P. kerguelenensis View in CoL has all three setae not longer than the dactylus.