Cephaloecetes enigmaticus Just, 2012, sp. nov.
Creators: name: Just, Jean
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Ischyroceridae
Cephaloecetes
Cephaloecetes enigmaticus

description: Cephaloecetes enigmaticus sp. nov.
Figures 20–22
Type fixation. Holotype, male, here designated.
Etymology. The species is so named because for some considerable time it presented an enigma to me.
Material examined. Holotype. 3, 5.3 mm, New South Wales, Jervis Bay, SE of Huskisson, off Moona Moona Creek, 35°03’S, 150°40’E, 8 m, rippled sand with detritus and shell just inside low rock reef covered with large brown algae, hand dredge on SCUBA, J. Just, P. Berents, R.T. Springthorpe, stn AU 65, 15 November 1984, AM P87061.
Paratypes. New South Wales, Jervis Bay: Same data as holotype, AM P87062 (ca. 200 specimens). Same data as holotype, AM P87063 (ca. 20 specimens, including ƤA). Same data as holotype, AM P87064 (13 specimens plus abodes: crab claws, broken mussels, polychaete tubes). SE of Huskisson, off Moona Moona Creek, 35°03’S, 150°40’E, 8 m, broadly rippled sand with detritus, hand dredge on SCUBA, J. Just, P. Berents, R.T. Springthorpe, stn AU 64, 15 November 1984, AM P87065 (1 3, 1 Ƥ). SE of Huskisson, off Moona Moona Creek, 35°03’S, 150°40’E, 8 m, broadly rippled sand with detritus, hand dredge on SCUBA, J. Just, P. Berents, R.T. Springthorpe, stn AU 64, 15 November 1984, AM P87066 (9 specimens including ovigerous ƤƤ). SE of Huskisson, off Moona Moona Creek, along inner edge of rock reef patch, 35°03’S, 150°40’E, 8 m, fine sand with detritus, hand dredge on SCUBA, J. Just, P. Berents, R.T. Springthorpe, stn AU 67, 16 November 1984, AM P87067 (1 specimen). SE of Huskisson, off Moona Moona Creek, along inner edge of rock reef patch, 35°03’S, 150°40’E, 8 m, fine sand with detritus, hand dredge on SCUBA, J. Just, P. Berents, R.T. Springthorpe, stn AU 67, 16 November 1984, AM P87068 (3 young). Off Moona Moona Creek, south east of Huskisson, New South Wales, Australia, 35°03’S, 150°40’E, 14m, silty sand with fine shell fragments, hand dredge, SCUBA. J. Just, P.B. Berents, R.T. Springthorpe, stn AU 75, 18 November 1984, AM P87069 (1 3). Off Moona Moona Creek, 35°03’S, 150°42’E, 8 m, sand, airlift, P.B. Berents, stn NSW 262, 17 December 1982, AM P87070, (21 specimens). Off Moona Moona Creek, 35°03’S, 150°42’E, 8 m, sand, airlift, P.B. Berents, stn NSW 263, 29 January 1983, AM P87071 (12 specimens). Off Moona Moona Creek, 35°03’S, 150°42’E, 8 m, sand, core, P.B. Berents and A.R. Jones, 18 March 1983, AM P87072 (2 Ƥ). Off Jervis Bay, approx. 35°10' S 150°50' E, 70 fms [128 m], FRV Kapala, 13 December 1984, AM P87158 (1 ovigerous Ƥ). SE of Lookout Point, Twofold Bay, 37°04’S, 149°55’E, 22 m, pipe dredge, S. Keable, P. Albertsen, stn EB-9, 21 February 1985, AM P36298 (1 Ƥ). Eden: NE of Mewstone Rock, 37°04’S, 149°55’E, 40 m, pipe dredge, S. Keable and P. Albertson, 22 February 1985, AM P36304 (1 Ƥ). Aslings Beach, Calle Calle Bay, 37°04’S, 149°55’E, 2 m, pipe dredge, S. Keable and P. Albertson, 22 February 1985, AM P36305 (1 specimen).
Victoria, Bass Strait: Western Bass Strait, 25 km S of Cape Otway, Victoria, 39°06.0’, 143°35.8’, 95 m, fine sand, epibenthic sled, M. Gomon et al., FRV Hai Kung, 81-HK-1, BSS stn 118, 31 January 1981, NMV J2634 (6 specimens, young and juveniles). Western Bass Strait, 36 km S of Cape Otway, 39°03’S, 143°51’E, 85 m, medium sand, Smith-McIntyre grab, G.C.B. Poore, HMAS Kimbla, stn BSS 47, 7 October 1980, NMV J9547. Western Bass Strait, 61 km WNW of Cape Farewell, King Island, 39°29’S, 143°14’E, 121 m, medium sand, pipe dredge, G.C.B. Poore, HMAS Kimbla, cruise 80-K-1, stn BSS 82, 10 October 1980, NMV J9548 (1 young). Central Bass Strait, 8 km off Cape Adansan, Three Hummock Island, Tasmania, 29 m, mainly sand, Smith-McIntyre grab, M. Gomon and G.C.B. Poore, FRV Sarda, stn BSS 111, 3 November 1980, NMV J9549. Central Bass Strait, 8 km off Cape Adansan, Three Hummock Island, Tasmania, 29 m, mainly sand, Smith-McIntyre grab, M. Gomon and G.C.B. Poore, FRV Sarda, stn BSS 111, 3 November 1980, NMV J9550 (4 specimens, 3,Ƥ). Central Bass Strait, 8 km off Cape Adansan, Three Hummock Island, Tasmania, 29 m, mainly sand, Smith-McIntyre grab, M. Gomon and G.C.B. Poore, FRV Sarda, stn BSS 111, 3 November 1980, NMV J9550 (4 specimens, 3,Ƥ). Eastern Bass Strait, 20 km SSW of Babel Island, Tasmania, 40°06.8’S, 148°24.3’E, 22 m, coarse shell, Smith-McIntyre grab, R. Wilson, RV Tangaroa, stn BSS 166, 14 November 1981, NMV J9551. Eastern Bass Strait, 50 km S of Port Albert, Victoria, 38°54.3’S, 147°13.4’E, 58 m, coarse shell, Smith-McIntyre grab/sled, R. Wilson, RV Tangaroa, stn BSS 176, NMV J9552 (4 young). Central Bass Strait, 65 km S of Cape Schanck, Victoria, 39°08.3’S, 144°43.9’E, 66 m, coarse sand, epibenthic sled, R. Wilson, RV Tangaroa, stn BSS 201, 23 November 1981, NMV J9553 (12 specimens, 3, Ƥ, young). Eastern Bass Strait, 20 km SSW of Babel Island, Tasmania, 40°06.8’S, 148°24.3’E, 22 m, coarse shell, R. Wilson, RV Tangaroa, stn BSS 166, 15 November 1981, NMV J62573 (1 specimen). Western Bass Strait, 38°32.0’S, 142°28.6’E, 52 m, medium sand, rock dredge, stn BSS 187, 20 November 1981, NMV J9575 (1 specimen).
Other material. Jervis Bay, New South Wales, off Moona Moona Creek, SE of Huskisson, 35°03’S, 150°40’E, 8 m, broadly rippled sand with detritus, hand dredge on SCUBA, J. Just, P. Berents, R.T. Springthorpe, stn AU 64, 15 November 1984, AM P87159 (many hundred specimens in abodes, mostly Cephaloecetes enigmaticus sp. nov., but specimens of Rhinoecetes albomasulosus sp. nov. may be present. Hence, the sample is not included in the paratypes).
Description (holotype, 3). Head as long as pereonite 1 and 2/3 of 2 combined along dorsal midline; midanterior depression very shallow, encompassing approximately 1/3 head length; entire head front margin forming blunt, obtuse angle of about 130°. Pseudorostrum straight, in dorsal view slender, acutely pointed, about 4 times longer than broad at base, reaching beyond eye lobes by its entire length. Eye lobes apically rounded in lateral view, lower anterior margin with tuft of 4–5 long simple setae.
Antenna 1 approximately as long as head and pereonites 1–4 combined, reaching to middle of antenna 2 peduncle article 5; flagellum of 6+ articles, approximately as long as peduncle articles 1 and half of 2 combined. Antenna 2 about as long as head, pereonites and pleonite 1 and half of 2 combined; ventral projection of peduncle article 2 approximately 1.5 as long as broad at base, with broadly rounded apex, with fringe of long simple setae laterally and shorter setae apically; article 5 0.9 length of 4; flagellum articles 1 and 2 with short robust setae.
Mouthparts, mandible palp article 1with 12 dorsal and 8–9 ventral long setae.
Gnathopod 1 propodus length 3.0 width, with 4 (left) and 5 (right) posterior robust setae. Gnathopod 2 propodus length 2.0 greatest width. Pereopods 3–4 basis with fringe of long and short setae along anterior margin, a single groups of long setae on posterior margin and a few long setae on distolateral surface; merus with fringe of long and short simple setae along anterior and posterior margin, with tuft of long setae on apex of anterodistal projection. Pereopods 5–6, anterodistal margin of basis with a several groups of long setae. Pereopod 7 propodus anterior margin with 3 groups of long setae and apical group of long setae.
Uropod 1 peduncle with dorsolateral row of simple setae proximally and 4 robust setae more distally, with single robust seta in distomedial corner; outer ramus stout, moderately spoon-shaped, 0.7 length of peduncle, lateral margin with 7 robust setae, dorsal surface with a few short simple setae; inner ramus 0.8 length of outer ramus, straight, smooth except for apical robust seta. Uropod 2 peduncle 0.5 length uropod 1 peduncle, dorsal surface with single simple seta, distolateral corner with group of longer setae; ramus 0. 5 length of peduncle, straight, with 2 distolateral robust setae before apical robust seta, reaching beyond ramus uropod 3 with half its length. Uropod 3 peduncle with rounded median projection carrying a few small simple setae; ramus with row of 6–7 unequally long setae. Telson width approximately 1.4 length, distal margin weakly concave.
Female. Pseudorostrum shorter than in male. Head front margin of illustrated Ƥ evenly convex, but most specimens with week anterior angle. Uropods with more robust setae. Sternal papillae in anterior half ventrally on pereonite 7 short, straight, length approximately twice width at base, forward pointing.
Size. Largest 3, 6.9 mm; largest Ƥ, 6.6 mm.
Variation. Head front margin shape of adults range from broadly angular as in the holotype to a more rare even convex curve; for younger specimens see Fig. 22. The Bass Strait population differ from specimens at the type locality in having the inner ramus of uropod 1 slightly shorter and broader with a few small simple setae.
Colour and biology (Jervis Bay population). Head and pereonites nearly uniformly dark brown except pereonites 3 and 4 (plus 5 and 6 in large specimens) with whitish dorsal saddle, head often with cream-white front margin, frons dark brown; urosome colourless. Antenna 2 peduncle article 3 whitish-brownish mottled, articles 4 and 5 with cream ring distally.
Abodes are comprised of an eclectic choice of empty crab claws, broken mussels, polychaete tubes and some micro prosobranchs.
Distribution. Australia, central New South Wales south to Bass Strait, 8 m (Jervis Bay)– 123 m (Bass Strait).
description: Published as part of Just, Jean, 2012, Siphonoecetini Just, 1983 (Crustacea, Amphipoda, Ischyroceridae) 9: New species in Rhinoecetes Just, 1983, Cephaloecetes gen. nov. and Neoecetes gen. nov. from the south-eastern Australian shelf, pp. 1-42 in Zootaxa 3234 on pages 33-38, DOI: 10.5281/zenodo.213268