Paracerapus polutovi
Creators: name: Lowry, J. K.
name: Berents, Penelope B.
Publisher: name: Zenodo
Year: 1996
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Ischyroceridae
Paracerapus
Paracerapus polutovi

description: <i>Paracerapus polutovi</i> (Gurjanova) Figs 19 - 21 <i>Cerapus polutovi</i> Gurjanova, 1951: 946, fig. 658. <i>Paracerapus polutovi.</i> Budnikova, 1989: 54. ? <i>Cerapus comparativus</i> Kudrjashov, 1975: 364, fig. 1. ? <i>Paracerapus comparativus.</i> Budnikova, 1989: 54. Type data. PARATYPES, male, 6.2 mm, AM P41691, female, 6.1 mm, male, AM P41692, East Kamchatka, Bering Sea, 20-29 m, 13 July 1934, stn 539. Material described. Based on paratype male, 6.2 mm; dimorphic characters based on paratype female, 6.1 mm. Diagnosis. <i>Antennae:</i> short, slender. <i>Mandible:</i> palp article 2 article 2 short, broad, length 1.8 x breadth, article 3 broad, clavate. <i>Maxilla</i> 1: outer plate with 10 setal-teeth. <i>Gnathopod</i> 2: male propodus broad, slightly curved, length 2.4 x width. <i>Peraeopod 7:</i> dactylus with row of accessory spines. <i>Pleopod 2:</i> biramous. <i>Pleopod</i> 3: biramous. Description. <i>Head:</i> rostrum very short, straight, apically rounded; lateral cephalic lobe well developed, ventral corner rounded, subocular margin deeply recessed, anteroventral corner subquadrate, ventral margin horizontal, posterior margin vertical. <i>Antenna</i> 1: short, 0.27 x body length, without scales; peduncular article 1 with very weak keel, length 0.7 x peduncular article 3; accessory flagellum absent; flagellum long, 5-articulate (female 5), aesthetascs absent, article 1 long, 2 x article <i>2. Antenna</i> 2: subequal in length to antenna 1; peduncle without scales; flagellum 5-articulate (female 6), article 1 long, 2.2 x article 2. <i>Epistome</i> and <i>upper lip:</i> fused. <i>Mandible:</i> left incisor with 4 cusps, right incisor with 4 cusps; left and right lacinia mobilis each with 4 cusps; left accessory setal row with 4 pappose robust setae, with 2 intermediate plumose setae, right accessory setal row with 4 pappose robust setae, with 3 intermediate plumose setae; molar triturating, molar flake on left and right side, molar seta only on right side; palp article 2 short, broad, length 1.8 x breadth, 1 x article 3 with 1 proximal A2-seta, with 5 posterior submarginal A2-setae, with 3 proximal and 10 posterior submarginal B2-setae, without D2-setae; article 3 clavate, long, 2.2 x breadth, with 1 proximal A3-seta, with distal A3-setae, with 10 posterior submarginal B3-setae, with 13 D3-setae and 3 E3-setae. <i>Maxilla</i> 1: inner plate small, with 2 simple apical setae; outer plate with 10 setal-teeth; palp with 6 terminal robust setae, without subterminal setae, flag seta present on distolateral corner. <i>Maxilla</i> 2: outer plate broader than inner; inner plate with setae distally along medial margin. <i>Maxilliped:</i> inner plate subrectangular with 3 nodular robust setae, without subterminal robust setae on medial corner, oblique setal row with 8 plumose setae; outer plate with 2 apical plumose setae, and 8 apicomedial robust setae; palp article 2, length 2 x breadth, article 3, length 1.7 x breadth. <i>Peraeonitel:</i> without lateral keel in male. <i>Peraeonite</i> 2: without sternal keel in male. <i>Peraeonite</i> 5: male, length 1.7 x breadth, female, length 0.8 x breadth. <i>Gnathopod</i> 1: subchelate; coxa not fused to peraeonite 1 in male or female, length 1.2 x depth, without anteroventral lobe; basis in male with sparse setae along anterior margin, in female with sparse setae along anterior margin, without robust setae along anterior margin; carpus length 0.76 x depth with setose posterior lobe, anterior margin without setae in male and female; propodus length 1.6 x depth, with 7 rows of anteromedial setae; palm acute, without setae, with barbed robust setae. <i>Gnathopod</i> 2: carpochelate in male, subchelate in female; coxa not fused to peraeonite 2 in male or female, length 1.7 x depth, without sharp anteroventral cusp; basis long, bottle-shaped, length 2.6 x breadth; carpus massive, very long, slender, length 1.5 x breadth, posterior margin without tooth; palm obtuse, broadly excavate, without anterodistal tooth, posterodistal tooth well defined, medium in size, length 1 x width, without robust setae; propodus broad, curved, length 2.4 x width, without tooth on posterior margin, with teeth along posterior margin; dactylus, length 10.4 x propodus. <i>Peraeopod</i> 3: coxa not fused to peraeonite 3 in male or female, length 2.3 x depth, without anteroventral lobe; basis length 1.1 x breadth, without inflated anterodorsal corner, with setae along anterior margin, without denticles along anterior margin; ischium length 1.2 x breadth; merus without ridges; carpus with 4 simple setae along distal half of anterior margin, with 10 simple setae along posterior margin; propodus with a few setae along posterior margin. <i>Peraeopod</i> 4: coxa not fused to peraeonite 4 in male or female, length 2.4 x depth, without anteroventral lobe; basis length 1.2 x breadth, without setal group along anterior margin; ischium long, length 1.4 x breadth; carpus without setae along distal half of anterior margin, with 7 simple setae along posterior margin; propodus with 8 simple setae along posterior margin. <i>Peraeopod</i> 5: coxa, length 1.5 x depth, without patches of small setae; anterior lobe of merus not extending beyond anterior margin of carpus, posterior lobe with 4 simple setae; propodus with 4 setae along posterior margin, dactylus short, uncinate with two accessory spines. <i>Peraeopod</i> 6: coxa without setal fringe ventrally, without patch of small setae; basis without anterior setae, without small denticles along posterodistal margin; merus, length 2.5 x breadth, without small anterodistallobe; carpus without anterodistal lobe, without posterodistal lobe, posterodistal corner bearing small setal bunch; propodus, anterodistal corner bearing large setal bunch; dactylus short, uncinate with rows of accessory spines. <i>Peraeopod</i> 7: coxa with posterodorsal lobe, without patch of small setae; basis without denticles along anteroproximal margin, without small denticles along posterodistal margin; merus, length 3 x breadth, without small anterodistal lobe, posterodistal corner bearing small setal bunch; carpus without anterodistal lobe, without posterodistal lobe, anterodistal corner bearing large setal bunch; propodus posterodistal corner bearing small setal bunch, anterodistal corner bearing small robust seta; dactylus short, uncinate with rows of accessory spines. <i>Oostegites:</i> from gnathopod 2 to peraeopod 5. <i>Gills:</i> from peraeopod 3 to peraeopod 6. <i>Pleopods</i> 1 <i>to</i> 3: decreasing in size. <i>Pleopod</i> 1: peduncle without patch of small setae, with 2 small distomedial hooks; rami subequal in length; inner ramus without patch of small setae, ll-articulate; outer ramus, article 1 with straight medial margin, 15-articulate. <i>Pleopod</i> 2: peduncle without patch of small setae, with 2 small distomedial hooks; biramous, inner ramus without patch of small setae, rami subequal in length, inner ramus 8-articulate; outer ramus broad, 1a-articulate, without patch of small setae. <i>Pleopod</i> 3: peduncle without patch of small setae, with 2 small distomedial hooks; rami subequal in length, without patch of small setae. <i>Uropod</i> 1: biramous, peduncle with distoventral corona of cuticular teeth, length 1.3 x outer ramus, without distoventral spine; outer ramus with lateral row of denticles, with 6 lateral setae, with large apical robust seta; inner ramus length 0.53 x outer ramus, without setae, with apical robust seta. <i>Uropod</i> 2: uniramous, peduncle length 2.5 x breadth, 2.8 x ramus; ramus small, with denticles and large apical robust seta. <i>Uropod 3:</i> uniramous peduncle length 1.6 x breadth; ramus with 3 curved spines. <i>Telson:</i> length 0.5 x breadth, cleft to base, each lobe with 22 to 25 anteriorly directed spines in two rows. Tube. Unknown. Remarks. According to Kudrjashov (1975) <i>Paracerapus polutovi</i> and <i>P. comparativus</i> (Kudrjashov, 1975) are closely related. Kudrjashov (1975) believed that the shape of the propodus of gnathopod 1 clearly distinguished the two species, but our illustration of the propodus is different to that of Gurjanova (1951), and appears more similar to that of Kudrjashov for <i>P. comparativus.</i> In males the carpochelate palm of <i>P. polutovi</i> is not as recessed as that of <i>P. comparativus,</i> but this condition may be related to the age of the individuals. It is possible that these two species are synonymous. <i>Paracerapus comparativus</i> is known from Iturup in the Kuril Islands, an island chain extending south from the Kamchatka Peninsula. <i>Paracerapus polutovi</i> occurs in the Commander Islands to the east of the Kamchatka Peninsula. <i>Paracerapus comparativus</i> needs to be redescribed in detail before its true relationship to <i>P. polutovi</i> can be considered. Distribution. East Kamchatka and Commander Island, Bering Sea, littoral to 29 m depth.
description: Published as part of <i>Lowry, J. K. &amp; Berents, Penelope B., 1996, The Ericthonius group, a new perpective on an old problem (Crustacea: Amphipoda: Corophioidea), pp. 75-109 in Records of the Australian Museum 48 (1)</i> on pages 103-107, DOI: 10.3853/j.0067-1975.48.1996.281, http://zenodo.org/record/4654913
description: {"references": ["Gurjanova, E. F., 1951. Bokoplavy morej SSSR i sopredel'nykh vod (Amphipoda-Gammaridea). Akademiia Nauk SSSR, Opredeliteli po Faune SSSR 41: 1 - 1029."]}