Bathypoma enigma Lowry &amp; Berents 1996, n.sp.
Creators: name: Lowry, J. K.
name: Berents, Penelope B.
Publisher: name: Zenodo
Year: 1996
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Ischyroceridae
Bathypoma
Bathypoma enigma

description: <i>Bathypoma enigma</i> n.sp. Figs 4 -8 <b>Type data.</b> HOLOTYPE, male, 2.07 mm, NMV J20777; PARATYPE, female, 2.60 mm, NMV J20778; PARATYPE male, NMV J20779; 31 PARATYPES, NMV J14644; PARATYPE male, 2 mm, AM P40434; 20 PARATYPES, AM P40435; east of Freycinet Peninsula, Tasmania, Australia, 42°2.20'S 148°38.7'E, coarse shelly sand, 800 rn, epibenthic sled, M.F. Goman and party on. RV <i>Franklin</i>, 27 July 1986, SLOPE 45; PARATYPE, NMV J14645, east of Freycinet Peninsula, Tasmania, Australia, 42°0.20'S 148°37.7'E, coarse shelly sand, 720 rn, epibenthic sled, M.F. Goman and party on RV <i>Franklin</i>, 27 July 1986, SLOPE 46; PARATYPE, NMV J14459, south of Point Hicks, Victoria, Australia, 38°19.60'S 149°24.30'E, rock, rubble, clay, sand, biogenic sediment, 930-951 rn, epibenthic sled, M.F. Goman and party on RV <i>Franklin</i>, 23 July 1986, SLOPE 33. <b>Material described.</b> Holotype male, 2.07 mm; dimorphic characters based on paratype female, 3.60 mm. <b>Description.</b> <i>Head:</i> rostrum short, curved down, apically acute, length 0.3 x head; lateral cephalic lobe well developed, ventral corner acute, subocular margin deeply recessed, anteroventral corner acute, ventral margin horizontal, posterior margin vertical. <i>Antenna 1:</i> long, 0.5 x body length, without scales; peduncular article 1 produced dorsodistally and dorsomedially, dorsodistal projection 0.4 along article 2, length 0.7 x peduncular article 3; accessory flagellum absent; flagellum long, 3­ articulate (female 2), aesthetascs present along ventral margin, article 1 long, 2.8 x article 2. <i>Antenna</i> 2: subequal in length to antenna 1; peduncle without scales; flagellum 4-articulate (female 4), article 1 long, 2.6 x article 2. <i>Epistome</i> and <i>upper lip:</i> fused, produced, acute. <i>Mandible:</i> left incisor with 5 cusps, right incisor with 5 cusps; left lacinia mobilis with 4 cusps, right with one large cusp and minutely serrate margin; left accessory setal row with 3 pappose robust setae, with 3 intermediate plumose setae, right accessory setal row with 2 pappose robust setae, with 2 intermediate plumose setae; molar triturating, molar flake on left and right side, molar seta absent; palp article 2 short, broad, length 2.1 x breadth, 1 x article 3, with 1 proximal and 1 distal A2-setae, 5 submarginal A2- and 4 submarginal B2-setae; article 3 clavate, long, 2.5 x· breadth, with 2 proximal A3-setae, 4 submarginal A3- and 4 submarginal B3-setae and 7 E3-setae terminally. <i>Maxilla</i> 1: inner plate small, with 1 simple apical seta; outer plate with 9 setal-teeth; right palp with 3 and left with 3 terminal robust setae, flag seta present on distolateral corner, right palp with 1 and left with 1 subterminal setae. <i>Maxilla</i> 2: outer plate slightly broader than inner; inner plate with setae distallyalong medial margin. <i>Maxilliped:</i> inner plate subrectangular with 3 nodular robust setae, without subterminal robust setae on medial corner, oblique setal row with 6 plumose setae; outer plate with 2 apical plumose setae, and 4 apicomedial robust setae; palp article 2, length 2.9 x breadth, article 3, length 2 x breadth. <i>Peraeonite</i> 5: male, length 1.4 x breadth, female, length 1.2 x breadth. <i>Gnathopod</i> 1: subchelate; coxa not fused to peraeonite 1 in male or female, length 1.3 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 1.1 x depth with setose posterior lobe, anterior margin without setae in male and female; propodus length 1.6 x depth, with 5 rows of anteromedial setae; palm extremely acute, sparsely setose, with barbed robust setae. <i>Gnathopod</i> 2: subchelate in male and female; coxa not fused to peraeonite 2 in male or female, length 1.7 x depth, without anteroventral lobe; basis short, broad, length 1.4 x breadth; carpus small, short, compressed, length 0.8 x breadth, posterior margin without tooth; propodus length 1.7 x depth; with broad tooth bearing 3 barbed robust setae defining proximal end of palm; dactylus 0.8 x as long as propodus. <i>Peraeopod</i> 3: coxa not fused to peraeonite 3 in male or female, length 2 x depth, without anteroventral lobe; basis length 1.6 x breadth, with inflated anterodorsal corner, with plumose setal group, without denticles along anterior margin; ischium length 1.6 x breadth; merus without ridges; carpus with 2 simple setae along distal half of anterior margin, with 3· plumose setae along distal half of posterior margin; propodus with 3 plumose setae along posterior margin. <i>Peraeopod</i> 4: coxa not fused to peraeonite 4 in male or female, length 2.2 x depth, without anteroventral lobe; basis length 1.5 x breadth, without setal group along anterior margin; ischium long, length 1.8 x breadth; carpus with 2 plumose setae along distal half of anterior margin, with 2 plumose setae along distal half of posterior margin; propodus with 3 plumose setae along posterior margin. <i>Peraeopod</i> 5: coxa, length 2.3 x depth, without patches of small setae; anterior lobe of merus not extending beyond anterior margin of carpus, posterior lobe with 3 plumose setae; propodus with 2 setae along posterior margin, dactylus short, uncinate with two accessory spines. <i>Peraeopod</i> 6: coxa with patch of small setae; basis with short, sparse setae anteriorly, with small denticles along posterior margin; merus, length 1.6 x breadth, without small anterodistal lobe; carpus without anterodistal lobe, with posterodistal lobe, posterodistal corner bearing small setal bunch; propodus, anterodistal corner bearing large setal bunch; dactylus short, uncinate with two accessory spines. <i>Peraeopod</i> 7: coxa without posterodorsal lobe, without patch of small setae; basis without denticles along anteroproximal margin, with small denticles along posterior margin; merus, length 2 x breadth, without small anterodistallobe, posterodistal corner bearing small setal bunch; carpus without anterodistallobe, with well-developed posterodistallobe, anterodistal corner bearing small setal bunch; propodus posterodistal corner bearing small setal bunch, anterodistal corner bearing large setal bunch; dactylus short, uncinate with two 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 with patch of small setae, with 2 small distomedial hooks; rami subequal in length; inner ramus without patch of small setae, 7-articulate; outer ramus, article 1 evenly swollen, 7-articulate. <i>Pleopod</i> 2: peduncle without patch of small setae, with 1 small distomedial hook; biramous, inner ramus without patch of small setae, reduced, I-articulate, length 0.4 x outer ramus; outer ramus broad, 4-articulate, without patch of small setae. <i>Pleopod</i> 3: peduncle without patch of small setae, without distomedial hooks; inner ramus absent. <i>Uropod</i> 1: biramous, peduncle with distoventral corona of cuticular teeth, length 1 x outer ramus, without distoventral spine; outer ramus with lateral row of denticles, with 4 lateral setae, with large apical robust seta; inner ramus length 0.8 x outer ramus, without setae, with apical robust seta. <i>Uropod</i> 2: uniramous, peduncle length 2.1 x breadth, 1.7 x ramus; ramus small, with denticles and 1 apical robust seta. <i>Uropod</i> 3: uniramous, peduncle length 1.7 x breadth; ramus with 2 curved spines. <i>Telson:</i> length 0.7 x breadth, cleft 0.90 x length, each lobe with 9 to 8 anteriorly directed spines in two rows. Parasites. Some specimens of <i>Bathypoma enigma</i> had a parasitic copepod attached to the head between antennae 1. These specimens were examined by Grygier (pers. comm.) and identified as males and females of an undescribed species of a nicothoid copepod <i>Sphaeronella</i> sp. The specimens are held at the Museum of Victoria, registration NMV J15063. Thbe. Composed of annulated fine grains occasionally with detritus and foraminiferans. Etymology. The name <i>enigma</i> refers to the subchelate second gnathopod of the species. Remarks. At present this is the sole species in the genus. Distribution. Off south-eastern Australia in 720 to 951 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 87-91, DOI: 10.3853/j.0067-1975.48.1996.281, http://zenodo.org/record/4654913