Talorchestia affinis Maccagno, 1936

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 : 364-369

Talorchestia affinis Maccagno, 1936

( Figs 9–12 )

Talorchestia affinis Maccagno, 1936: 181 (Assab, Eritrea).― Froglia, 2001: 70, Appendix 2.

Talorchestia franchetti Maccagno, 1936: 179 (Assab, Eritrea).― Froglia, 2001: 70, Appendix 2.

Talorchestia martensii .― Ruffo, 1938: 169 ( Eritrea: Difnen Island, Red Sea, no illustrations, no description).―? Ercolini, 1964a: 119 (ethology).―? Ercolini, 1964b: 138 (ethology).―? Pardi & Ercolini, 1966: 80 (ethology).―? Pardi, 1967: 44 (ethol- ogy).― Ruffo, 1969: 40, fig. 12 (map) (Goliath Bay, Entedebir Island, Dahlak Archipelago, and Massawa, Eritrea; Port Sudan, Sudan; Ghardaqa, Egypt; all Red Sea, no illustrations or description).―? Pardi, Ercolini, Ferrara, Scapini & Ugo- lini, 1984: 312 (ethology).― Jones, 1986: 150, pl. 41.―? Pardi, Ugolini, Faqi, Scapini & Ercolini, 1988: 79 (ethology).―? Ugolini & Pardi, 1992: 279 (ethology, Kenya: Malindi).―? Ugolini, 2001: 193 (ethology, Kenya: Malindi, Kenya (3°13’S 40°07’E )).―? Ugolini, 2002: 269 (ethology, Kenya: Malindi, Kenya (3°13’S 40°07’E )).― Ugolini & Ciolini, 2016: 1.

Talorchestia brito .― Zakaria & Farrag, 2012: 24 (Safaga, 26°44′N 33°56′E, ecology).

Type material. Lectotype, male, 10 mm, MSNG 60962, paralectotypes, many specimens, MSNG 60963, lectotype, immature specimen of T. franchetti , MSNG 60964, paralectotypes, immature specimens of T. franchetti , MSNG 60965, Assab, Eritrea, (~ 13°01′N 42°44′ E), February 1929.

Type locality. Assab , Eritrea, (~ 13°01′N 42°44′E) .

Additional material. Male, 14 mm, AM P.99350, (SEM pin and 4 SEM stubs), Gazi Beach, Gazi (Maftaha) Bay, Kenya (4°25’S 39°30’E), coll. S. Baldanzi, October, 2018. 1 female, AM P.99351 (SEM pin and SEM stub), 11 males, 7 females, AM P.88478, same locality. 1 male, MSNVR Cr PS0007, MSNVR Cr PS0011– MSNVR Cr PS0014 (SEM pin and 4 SEM stubs), 1 female, MSNVR Cr PS0008, MSNVRCr PS0015 (SEM pin and SEM stub), 1 male, 2 females, several juveniles, MSNVR, Port Sudan, Sudan (19°37′N 37°13′E), V. Storch, 25 February 1967. 1 male, MSNVRCr PS0009, MSNVRCr PS0016–MSNVRCr PS00019 (SEM pin and 4 SEM stubs), 1 female, MSNVRCr PS0010, MSNVRCr PS0020 (SEM pin and SEM stub), many male and female specimens, MSNVR, Hurghada , Egypt (27°15′28″N 33°48′42″E), V. Storch, 3 April 1967 .

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

Habitat. Supralittoral.

Description. Based on male, 14 mm, AM P.99350.

Head with five groups of long, slender scales along ventroproximal surface. Antenna 2 85% of body length; article 5 longer than article 4, peduncular articles with sparse, small robust setae, flagellar articles final article large, cone-shaped forming a virgula divina, flagellar articles with apical cluster of ‘imbricated’ setae. Labrum without robust setae; upper lip epistome with many pores; upper lip with apical setal patch. Labium distolateral setal tuft absent; with vestigial inner plates. Mandible left lacinia mobilis 5-cuspidate (fifth tiny). Maxilla 1 with small palp, 1-articulate.

Pereon. Gnathopod 1 sexually dimorphic; parachelate; coxa smaller than coxa 2; palmate lobes in male only; carpus longer than propodus, 2 × as long as propodus, 2.7 × as long as broad; propodus subrectangular, anterior margin with 6 groups of robust setae, medial surface with 6 cuspidate setae; palm with 5 serrate setae, palm transverse, without spine patch on posterodistal corner; dactylus longer than palm, simplidactylate, without anterodistal denticular patch. Gnathopod 2 sexually dimorphic; basis slender; ischium without lobe on anterior margin, without anterodistal lobe on medial surface; carpus triangular, reduced (enclosed by merus and propodus), posterior lobe absent, not projecting between merus and propodus; propodus subrhomboidal, 1.8 × as long as wide; palm acute, reaching about 49% along posterior margin, smooth, with rounded protuberance near dactylar hinge, lined with robust setae, posteromedial surface of propodus with groove, without cuticular patch at corner of palm; dactylus slightly longer than palm, broadly curved, distally straight or curved, without anteroproximal bump, posterior margin with posteroproximal sinus and small projection. Pereopods 2–4 coxae as wide as deep. Pereopods 3–7 dactyli without anterodistal patch of many rows of tiny setae. Pereopod 4 significantly shorter than pereopod 3 (?); carpus significantly shorter than carpus of pereopod 3. Pereopod 5 propodus distinctly longer than carpus. Pereopod 6 subequal in length to pereopod 7; coxa posterior lobe inner view posteroventral corner rounded, posterior margin oblique to ventral margin, posterior lobe with ridge, posterior lobe with 5 marginal setae. Pereopod 7 basis lateral sulcus present, slightly pronounced, posterodistal lobe absent; distal articles (merus and carpus) slender.

Pleon. Pleopods 1–3 biramous. Epimeron 2 subequal in length to epimeron 3. Epimeron 3 posterior margin smooth, with setae (minute), posteroventral corner with small subacute tooth, ventral margin without robust setae. Uropod 1 peduncle with 14–15 robust setae, small distolateral robust seta present, small (less than 1/4 length of exopod), with simple tip; endopod subequal in length to exopod, with about 12 marginal robust setae in 2 rows; exopod without marginal robust setae. Uropod 2 peduncle with 10+ robust setae; endopod subequal in length to exopod, with 4 lateral and 4 medial marginal robust setae; exopod with 3 marginal robust setae in 1 row. Uropod 3 peduncle with 9 robust setae; ramus not fused to peduncle, subequal in length to peduncle, ramus 3 × as long as broad, linear (narrowing), with 3 marginal robust setae, with more than 5 apical setae. Telson dorsal midline entire, with about 8 marginal and apical robust setae per lobe.

Female (sexually dimorphic characters). Based on female, 11.3 mm, AM P.99351. Antenna 2 less than half body length; article 5 subequal in length to article 4, flagellar articles final article large, cone-shaped forming a modified virgula divina. Gnathopod 1 simple; posterior margin of merus, carpus and propodus each without lobe covered in palmate setae; propodus 2.9 × as long as broad; anterior margin with 4 groups of robust setae. Gnathopod 2 mitten-shaped; basis expanded anteromedially; posterior margin of carpus and propodus each with lobe covered in palmate setae; carpus well developed (not enclosed by merus and propodus), posterior lobe present, projecting between merus and propodus; propodus twice as long as wide, palm obtuse, without protuberance or shelf near dactylar hinge; dactylus shorter than palm, straight, posterior margin smooth, not modified distally, blunt. Pereopod 6 posterior lobe with 9 marginal setae. Pereopod 7 posterodistal lobe present, shallow, broadly subquadrate. Oo- stegites long (length greater than 2 × width), longer than wide, weakly setose, 14–18 setae with simple smooth tips. Uropod 1 peduncle with about 14 robust setae; endopod with about 10 marginal robust setae. Uropod 2 peduncle with about 8 robust setae; endopod slightly shorter than exopod, with 3 medial robust setae. Uropod 3 ramus partially fused to peduncle; ramus shorter than peduncle, 2.4 × as long as broad. Telson with 9 setae per lobe.

Remarks. Talorchestia affinis appears to be the sister species of Talorchestia qeshm . They are very similar and differ mainly in the shape of the palm of male gnathopod 2 and the number of robust setae on the telson (8 in T. affinis and at least 10 in T. qeshm ). It differs from T. martensii (of Miyamoto & Morino 1999) in the shape of male G2 posterior margin straight, more robust setae on the palm.

Distribution. Kenya. Gazi Bay (current study). Red Sea coast: Hurghada, Egypt; Port Sudan, Sudan ( Ruffo 1938, 1969; this study) Goliath Bay, Entedebir Island, Dahlak Archipelago, and Massawa, Eritrea; Port Sudan, Sudan; Ghardaqa, Egypt ( Ruffo 1969). East African coat: Mogadishu, Somalia ( Pardi et al. 1984, Pardi et al. 1988).

Figures

FIGURE 9. Talorchestia affinis Maccagno, 1936, male, 14 mm, AM P.99350, female,AM P.99351, Gazi Beach, Gazi (Maftaha) Bay, Kenya (4°25’S 39°30’E). Scale lines for habitus represent 1.0 mm, H represents 0.5 mm, remainder represent 0.1 mm.

FIGURE 10. Talorchestia affinis Maccagno, 1936, male, 14 mm, AM P. 99350, female, AM P. 99351, Gazi Beach, Gazi (Maftaha) Bay, Kenya. Scale lines for U1–3 represent 0.2 mm, T represents 0.1 mm, remainder represent 0.5 mm.

FIGURE 11. Talorchestia affinis Maccagno, 1936, male, 14 mm, AM P. 99350, Gazi Beach, Gazi (Maftaha) Bay, Kenya. Scale lines represent 0.5 mm.

FIGURE 12. Talorchestia affinis Maccagno, 1936, male, 14 mm, AM P. 99350, Gazi Beach, Gazi (Maftaha) Bay, Kenya. Scale lines represent 0.5 mm.