Cephaloecetes schioettei, Just, Jean, 2017

Just, Jean, 2017, Siphonoecetini Just, 1983 (Crustacea, Amphipoda, Ischyroceridae) 11: Cephaloecetes schioettei sp. nov. from The Philippines, Zootaxa 4272 (2), pp. 296-300 : 297-300

Cephaloecetes schioettei sp. nov. ( Figs 1–2 )

Type fixation. Holotype, ♂, here designated.

Etymology. The species is named for my friend Mr. Tom Schiøtte, Assistant Curator, Zoological Museum, University of Copenhagen, for excellent and ever cheerful help in and out of the Philippine waters.

Material examined. Holotype. ♂, 4.0 mm, Mactan Island , Cebu, The Philippines, off Mundo Island, 10°17.2’N 124°0.4’E, 5 m, coral sand, hand dredge, J. Just & T. Schiøtte, stn PH 27, 18 November 1982, ZMUC-CRU-8691.

Paratypes (The Philippines, Cebu, Mactan Island, 92 specimens in all). South of Panguian Point , 10°19.65’N 124°02.5’E, 5 m, coral sand with scattered sea grass, hand dredge, J. Just & T. Schiøtte, stn PH 17, 15 November 1982, ZMUC-CRU-8692 (1 ♂, 5 ovigerous ♀, 7 young, many abodes; see Fig. 1 x). Same data stn PH 17 as preceding, ZMUC- CRU-8693 (16 specimens, ♂, ♀, juveniles). Same data as preceding, stn PH 18, ZMUC-CRU-8694 (1♂, 3 ovigerous ♀, 3 young). South of Panguian Point , 10°19.65’N 124°02.5’E, 3 m, coral sand with scattered sea grass, hand dredge, J. Just & T. Schiøtte, stn PH 19, 15 November 1982, ZMUC-CRU-8695 (6 ovigerous ♀, 2 ♀, 6 juvenile, many abodes). South of Panguian Point , 10°19.65’N 124°02.5’E, 2.5 m, coral sand with scattered sea grass, hand dredge, J. Just & T. Schiøtte, stn PH 21, 15 November 1982, ZMUC-CRU-8696 (1 ovigerous ♀ with abode). Sulpa Island , 10°14.45’N 124°0.47’E, 4 m, coarse coral sand with scattered sea grass, hand dredge, J. Just & T. Schiøtte, stn PH 31, 21 November 1982, ZMUC- CRU-8697 (1 juvenile) . Same data as preceding; stn PH 32, ZMUC-CRU-8698 (♀ A, ovigerous). North of Maribago , 10°17.4’N 124°0.4’E, 5 m, coarse coral sand, hand dredge, J. Just & T. Schiøtte, stn PH 33, 22 November 1982, ZMUC- CRU-8699 (1 juvenile) . East side of Magellan Bay, 10°19.65’N 124°01.80’E, 5 m, coral sand with scattered sea grass, hand dredge, J. Just & T. Schiøtte, stn PH 39, 23 November 1982, ZMUC-CRU-8700 (2 ♂, 1 ♀, 3 juvenile, several abodes). North of Maribago , 10°17.4’N 124°0.4’E, 5 m, coarse coral sand, hand dredge, J. Just & T. Schiøtte, stn PH 40, 23 November 1982, ZMUC-CRU-8701 (1 ♂, 3 young, several abodes). East side of Magellan Bay , 10°19.65’N 124°01.80’E, 6 m, coarse coral sand, hand dredge, J. Just & T. Schiøtte, stn PH 41, 23 November 1982, ZMUC-CRU- 8702 (1 ♂, 1 ♀, 1 juvenile) . Tip of Panguian Point, 10°20.05’N 124°02.68’E, 6–7 m, coral sand, hand dredge, J. Just & T. Schiøtte, stn PH 42, 29 November 1982, ZMUC-CRU-8703 (1 ♂, 1 ovigerous ♀, 2 ♀, 5 juveniles, 6 abodes). Tip of Panguian Point , 10°20.05’N 124°02.68’E, 5 m, coral sand with scattered sea grass, hand dredge, J. Just & T. Schiøtte, stn PH 43, 29 November 1982, ZMUC-CRU-8704 (2 ♂, 1 ovigerous ♀, 13 young, many abodes).

Description (holotype, ♂). Head as long as pereonite 1 and half of 2 combined along dorsal midline; head not anterodorsally depressed; entire head front margin forming blunt, obtuse angle of about 100°. Pseudorostrum straight, in dorsal view slender, acutely pointed, about as long as broad at base in lateral view, not reaching beyond eye lobes. Eye lobes truncate in lateral view, lower anterior margin with a single long simple setae. Antenna 1 approximately as long as head and pereonites 1–6 combined, reaching to the apex of antenna 2 peduncle article 5; flagellum of 7+ articles, approximately as long as peduncle articles 1 and 2 combined; peduncle article 1 with single robust seta proximally on ventral margin. Antenna 2 about as long as head, pereonites and pleonite 1 and half of 2 combined; ventral projection of peduncle article 2 approximately 1.3 as long as broad at base, with broadly rounded apex, with fringe of long simple setae laterally and shorter setae apically; peduncle article 5 0.8 length of 4; flagellum articles 1 and 2 with medium size robust setae; peduncle article 3 with 1 distal and 2 proximal robust setae on medial surface.

Mouthparts, mandible palp article 1 with about 12 long setae.

Gnathopod 1 propodus length 3.0 width, with 3 posterior robust setae; basis lateral anterior margin covered with tiny scales. Gnathopod 2 basis medioanterior margin with row of recurved robust setae, lateroanterior margin finely serrate; propodus length 1.7 greatest width. Coxal plates 1 and 2 longer than wide at base, pointed with blunt apex. Pereopods 3– 4 basis with a few long and short setae on anterior and posterior margins; merus with a few long setae on anterior margin, posterior margin with tufts of long and short setae. Pereopods 5–6 with few simple setae. Pereopod 7 propodus anterior margin with 2 groups of long setae and apical group of long setae.

Uropod 1 peduncle with a couple of laterodorsal and a few apical simple setae; outer ramus slender, cylindrical, 0.7 length of peduncle, lateral margin with 4 robust setae, dorsal surface without simple setae; inner ramus 0.8 length of outer ramus, straight, smooth except for apical robust seta, ramus with 1 distolateral robust setae before apical robust seta. Uropod 2 peduncle 0.45 length uropod 1 peduncle, dorsal surface with single simple seta distally; ramus 0.8 length of peduncle, straight, reaching beyond ramus uropod 3 with about 1/4 of its length. Uropod 3 peduncle with rounded median projection carrying a single small simple seta; ramus with 2–3 unequally long setae. Uropod 1 peduncle and rami and uropod 2 ramus covered with numerous tiny pointed cuticle scales (not illustrated). Telson width approximately 1.2 visible length, distal margin weakly concave.

Female. Pseudorostrum shorter than in male. Head of front margin with wider, more rounded mid-angle. Antenna 1 article 1 with row of robust setae along ventral margin. Antenna 2 article 3 of peduncle with several ventral and row of medial robust setae. Uropod 1 outer ramus with more robust setae. Sternal papillae long, curved, forward pointing ventrally in anterior half of pereonite 7.

Size. Largest ♂, 4.0 mm; largest ♀, 4.6 mm.

Colour and biology. Light sandy mottled, antennae colourless except reddish at extreme tip of antenna 1; eyes white with bright red ocelles.

Abodes are comprised of micro prosobranchs, crab claws, broken mussels, polychaete tubes and some hollowed coral rubble. Sediment tubes frequently end with two large parallel slabs ( Fig. 1 x) which may stabilize the abode against tidal or wind driven water movements along the shallow bottom.

Distribution. Mactan Island, Cebu, The Philippines, 2.5– 7 m.

Remarks. Cephaloecetes schioettei sp. nov. differs from C. enigmaticus primarily by its much shorter pseudorostrum, broadly truncate eyelobes in lateral view, antenna 1 longer relative to antenna 2 and to the body, more robust setae on peduncle article 1 of antennae 1 and antenna 2 peduncle article 3, recurved robust setae on anteromedial margin of gnathopod 2 basis, elongate coxal plates 1 and 2, long curved sternal papillae, and uropod 1 peduncle without robust setae; the new species is generally less setose (simple setae) than C. enigmaticus .

Figures

FIGURE 1. Cephaloecetes schioettei sp. nov. Holotype, male: a 2 flag, antenna 2 flagellum; c dv, head dorsal view; c lv, head lateral view; us, urosome dorsal view; vp, ventral projection, article 2, antenna 2. X, paratype abodes (stn PH 40). Habitus scale 1.0 mm.

FIGURE 2. Cephaloecetes schioettei sp. nov. H, holotype, male; F, paratype, female A (PH 32); M, paratype, male. c dv, head dorsal view; c lv, head and antennae lateral view; gp 1 – gp 2, gnathopod 1 and 2; md, mandible; mx 1 maxilla 1; sp, sternal papillae on pereonite 7, left view; us, urosome dorsal view. Scale for Fc lv: 1.0 mm.