Eudactylopus fasciatus Sewell, 1940

Eudactylopus fasciatus Sewell, 1940 View in CoL

Sampling locality. Bangaram Lagoon, Lakshadweep

Material examined. Holotype: Female, India, Kerala, Lakshadweep, Bangaram (10 º 56’27.38’’N 72 º 17’29.02’’E). Specimens were dissected and mounted (voucher no. MBM /DBT/15). Male specimens were dissected and mounted on 4 slides (voucher no. MBM /DBT/21) from Bangaram Island Lakshadweep. GoogleMaps

Redescription of female. Total body length 1.164 mm, measured from anterior margin of rostrum to posterior margin of caudal rami. Largest width measured at posterior margin of cephalic shield, 0.451 mm. Body stout and fusiform ( Fig. 2A, B, C View Figure 2 ). Rostrum prominent, triangular, slightly curved downwards, rounded at its tip. Prosome comprising cephalothorax with completely fused first pedigerous somite and 3 free pedigerous somites.All somites with an incised type of hyaline frill except fifth pedigerous somite ( Fig.2E View Figure 2 ). Caudal rami cylindrical, slightly longer than broad, with 6 elements inserted distally.The outer distal edge of 6 ramus showing slight prolongation. Seta I bare, seta II bare and shortest, seta III longer than seta I and II, seta IV and V thickened and long, seta VI bulbous basally and with setules along the inner margin, and seta VII with setules at base and arising from inner dorsal surface.( Figs. 2D View Figure 2 , 8G).Dorsal surface of cephalic shield with 8 longitudinal colored bands of which 2 left and 2 right (1, 2, 7, and 8 th, see Fig. 8A) being considered lateral bands. Dorsal bands 3, 4, 5, and 6 reaching mid-dorsal margin of P5 bearing somite. Five bands continuing downwards onto first urosomite (P5 bearing somite). Rostrum triangular, linguiform reaching beyond length of first antennular segment. Urosome 5-segmented, comprising P5 bearing somite, genital and first abdominal somites fused to form genital double somite and 3 abdominal somites, respectively. Each abdominal somite 1, 2, and 3 with incised type of hyaline frill and anal somite bearing pair of bifid-tipped plates.

Antennule ( Fig. 3A View Figure 3 ) 9-segmented, about as long as cephalothorax. First segment largest bearing an inner longitudinal row of spinules and 1 short seta. Second segment with 11 setae. Third segment with 1 seta in posterior margin and 4 setae on outer distal margin. Fourth segment with 2 setae on outer distal margin, long slender aesthetasc fused basally to 1 apical seta. Fifth segment with 1 outer distal seta. Sixth segment with 3 setae on outer distal margin. Seventh and eighth segments with 1 apical and 1 inner setae. Ninth segment with 4 setae and 1 aesthetasc.

Armature formula: 1-1/2-11/3-5/4-3+1(Ae)/5- 1/6-3/7-2/8-2/9-4+1(Ae).

Antenna ( Fig. 3C View Figure 3 ) with coxa, allobasis and free endopodal segment. Coxa small, unornamented. Allobasis (basis and first endopodal segment fused) with 1 exopodal seta on distal third and ornamented with posterior row of minute spinules.Exp-2 segmented, exp-1 longer than exp-2, exp-1 with 1 subapical seta, and exp-2 with 1 subapical and 2 apical setae. Free endopodal segment with 2 inner lateral spines, 2 inner distal spines, 2 geniculate distal setae, 1 outer distal seta, and 1short outer seta.Mouthparts well developed. Labrum ( Fig. 4A View Figure 4 ) sclerotized, numerous hairs on its posterior margin. Mandible ( Fig. 4B View Figure 4 ) with coxa and short basis fused with coxa. Gnathobase with strong chitinized teeth. Cutting edge with4 blunt teeth with slenderspinuledorsally.Palp2-segmented,1segmented exopod (fused to basis basally)and endopod.Basis with 2 setae. Exopod with 2 setae on outer distal corner of coxa-basis, endopod with 6 setae. Maxillule ( Fig. 4C View Figure 4 ) arthrite of pre-coxa with 7 strong spines along distal margin and claw-like spine on apical margin. Coxa elongated, 3 apical setae on maxillular coxa. Maxilla ( Fig. 4D View Figure 4 ) pre-coxa and coxa fused, outer margin with small spinules.Syncoxa armed with 3 endites.Proximal endite with 2 bipinnate spines; middle with 1bipinnate seta and spine, distal endite with 2 bipinnate spines. Basal complex with basis drawn into strong claw with 2 small setae near base. Maxilliped ( Fig. 4E View Figure 4 ) prehensile, subchelate, 3-segmented, composed of syncoxa with 3 spinulose setae on inner distal margin and 2 rows of spinules on proximal and distal margins. Enp shorter than basis bearing 1 seta;enp first segment with spinular row on inner margin, distal segment forming a strong claw.

P1 ( Figs. 5A View Figure 5 , 8A) transversely elongate intercoxal sclerite. Coxa with 1 anterior row of outer spinules. Basis with 1 transverse median row of spinules close to inner margin, with additional spinules at base of basal armature and between rami; basal armature consisting of 1 strong inner and outer spine. Exopod 3-segmented,shorter than endopod. Exopod 1 with 1 robust outer spine, some outer and some distal spinules; exopod 2 longest with 3 inner spinules proximally, with 1 subdistal inner seta and 1 outer median spine; exopod 3 small, with 3 outer spines and 1 serrated seta. Endopod 2-segmented; endopod 1 elongate, as long as exopod, with 1 long inner seta; enp 2 small, with 2 claws of different lengths, and 1 tiny seta.

P2–P4 with large intercoxal sclerite and well developedprecoxa.Exopodandendopod3-segmented. P2 ( Figs. 5B View Figure 5 , 8B) basis with 1 strong outer spine; with spinular rows on anterior surface. Exopod 1 with triangular outer distal protuberance with rows of outer spinules, and with 1 outer spine and 1 bipinnate subdistal inner seta; exopod 2 shorter than exp1, with triangular inner and outer distal protuberances with some outer spinules and armed with 1 outer spine and 1 bipinnate subdistal inner seta; exopod3 with 3 outer spines, 1 long apical outer spine, 1 apical inner seta, and 2 bipinnate inner setae.Endopod 1 with triangular inner and outer distal protuberance with some outer spinules and armed with 1 long inner bipinnate seta; endopod 2 with 2 long bipinnate inner setae;endopod 3 with 1 outer spine, 2 apical and 2 inner setae.

P3 ( Figs. 6A View Figure 6 , 8C) similar to P2, except for basis with 1 thin seta.

P4 ( Figs. 6B View Figure 6 , 8D) basis with thin outer seta as in P3. Exopod 1 and exopod 2 with triangular outer protuberance distally, with outer and inner spinules, with 1 outer spine and 1 subdistal inner seta, exopod 3 with 3 outer spines, 1 long apical outer spine, 1 apical bipinnate inner seta, and 3 long inner, subdistal bipinnate setae. Endopod 1 with inner and outer triangular distal protuberances, endopod 2 wider than enp-1, with inner and outer triangular distal protuberance with 1 long bipinnate inner seta; endopod3 with 1small outer spine, 2 apical and 2inner bipinnate setae. P5 ( Figs. 2B View Figure 2 , 7A View Figure 7 , 8E) well developed; baso - endopod and exopod separated, baso - endopod larger than exopod, with outer seta arising from long setophore. Endopodal lobe larger than exopod, with 4 distal setae, with small spinule between setae and subdistally along outer margin. Exopod with 6 setae on the distal margin with different lengths.Outer and distal margins armed with fine setules.

P6 ( Figs. 7B View Figure 7 , 8F) unsegmented with small protuberance bearing 3 setae.