Gazia gazi, Lowry & Springthorpe, 2019

Lowry, J. K. & Springthorpe, R. T., 2019, Talitrid amphipods from India, East Africa and the Red Sea (Amphipoda, Senticaudata, Talitroidea, Talitridae), Zootaxa 4638 (3), pp. 351-378 : 359-360

Gazia gazi sp. nov.

( Figs 6–8 )

Type material. Holotype, male, 8.9 mm, AM P.99349, (SEM pin and 4 SEM stubs), Gazi Beach , Gazi (Maftaha) Bay, Kenya (4°25’S 39°30’E).

Type locality. Gazi Beach , Gazi (Maftaha) Bay, Kenya (4°25’S 39°30’E) .

Ecological type. Beach-hoppers (mainly coastal supralittoral/intertidal leaf-litter/wrack, non-substrate modifying talitrids).

Etymology. Named for the type locality, Gazi Beach.

Description. Based on holotype, male, 8.9 mm, AM P.99349.

Head. Antenna 1 short, rarely longer than peduncular article 4 of antenna 2. Antenna 2 less than half body length; peduncular articles slender, article 5 longer than article 4, peduncular articles with many small robust setae, flagellar articles final article large, cone-shaped forming a virgula divina, flagellar articles with apical cluster of ‘imbricated’ setae. Labium distolateral setal tuft present; with vestigial inner plates. Mandible left lacinia mobilis 4-cuspidate. Maxilla 1 with small palp, 1- or 2-articulate. Maxilliped palp article 2 distomedial lobe well developed; article 4 fused with article 3.

Pereon. Gnathopod 1 subchelate; coxa smaller than coxa 2; posterior margin of carpus and propodus each with lobe covered in palmate setae; carpus longer than propodus, 1.6 × as long as propodus, 1.9 × as long as broad; propodus ‘subtriangular’ with well-developed posterodistal lobe, anterior margin with 3 groups of robust setae; palm with 11 serrate setae, transverse, without spine patch on posterodistal corner, dactylus subequal in length to palm, simplidactylate, without anterodistal denticular patch. Gnathopod 2 subchelate; basis slender; ischium without lobe on anterior margin, with distally rounded anterodistal lobe on medial surface; posterior margin of merus, carpus and propodus each without lobe covered in palmate setae; carpus triangular, reduced (enclosed by merus and propodus), posterior lobe absent, not projecting between merus and propodus; propodus subovate, twice as long as wide; palm extremely acute, reaching between 51–55% (53%) along posterior margin, strongly toothed, incised or sinuous, with small rounded protuberance near dactylar hinge, immediate deep sinus and straight ridge along palm, lined with robust setae, with small distal palmar sinus, without midpalmar protuberances, posteromedial surface of propodus with groove, with cuticular patch at corner of palm; dactylus slightly longer than palm, pick-shaped, posterior margin with posteroproximal sinus and large projection, not modified distally, blunt. Pereopods 2–4 coxae wider than deep. Pereopods 3–7 cuspidactylate; dactyli with or without anterodistal patch of many rows of tiny setae. Pereopod 3 dactylus without anterodistal patch. Pereopod 4 subequal to or slightly shorter than pereopod 3; carpus similar in length to pereopod 3 carpus; dactylus thickened proximally with a weak notch midway along posterior margin, dactylus without anterodistal denticular patch. Pereopod 5 propodus distinctly longer than carpus; dactylus with anterodistal denticulate patch. Pereopods 6–7 neither sexually dimorphic. Pereopod 6 subequal in length to pereopod 7; coxa posterior lobe inner view posteroventral corner rounded, posterior lobe without ridge, with 3–4 marginal setae. Pereopod 7 basis lateral sulcus absent, posterior margin with distinct minute serrations, each with a small seta, posterodistal lobe present, rounded, produced downwards almost to merus; distal articles (merus and carpus) slender; merus posterior margin straight.

Pleon. Pleopods 1–3 biramous, all well developed. Epimera 2–3 each with slits just above ventral margins. Epimeron 2 with 36 slits. Epimeron 3 with 24+ slits, posterior margin smooth, without setae, posteroventral corner subquadrate, ventral margin without robust setae. Uropod 1 peduncle with 13 robust setae, distolateral robust seta present, small (less than 1/4 length of exopod), with simple tip; endopod subequal in length to exopod, with 4 marginal robust setae in 1 row; exopod without marginal robust setae. Uropod 2 peduncle with 7 robust setae; endopod subequal in length to exopod, with 4 marginal robust setae in 2 rows, with 2 lateral robust setae, with 2 medial robust setae; exopod with 2 marginal robust setae in 1 row. Uropod 3 peduncle with 4 robust setae; ramus not fused to peduncle; ramus shorter than peduncle, 2 × as long as broad, linear (narrowing), with 3 apical setae. Telson longer than broad, apically incised, dorsal midline entire, with marginal and apical robust setae, with 7 robust setae per lobe.

Female. Unknown.

Remarks. Gazia gazi sp. nov. is most similar to G. ancheidos (K.H. Barnard, 1916) from southern Africa and G. itampolo ( Lowry & Springthorpe, 2015a) from Madagascar. Gazia gazi differs from both of these species in the distinctive shape of the male gnathopod 2 propodus and the length of the palm (54% in G. gazi ; 45% in G. ancheidos and 36% in G. itampolo).

This is the first record of the Floresorchestia complex from eastern Africa and significantly extends its distribution in the Indian Ocean.

Distribution. Kenya. Gazi beach (current study).

Figures

FIGURE 6. Gazia gazi gen. nov., sp. nov., holotype, male, 8.9 mm, AM P.99349, Gazi Beach, Gazi (Maftaha) Bay, Kenya. Scale lines represent 0.1 mm.

FIGURE 7. Gazia gazi gen. nov., sp. nov., holotype, male, 8.9 mm, AM P.99349, Gazi Beach, Gazi (Maftaha) Bay, Kenya. Scale lines for U3, T represent 0.1 mm, U1–2 represent 0.2 mm, G1–2, EP1–3 represent 0.5 mm.

FIGURE 8. Gazia gazi gen. nov., sp. nov., holotype, male, 8.9 mm, AM P.99349, Gazi Beach, Gazi (Maftaha) Bay, Kenya. Scale lines represent 0.5 mm.