Paranamixis sommelieri, Kristine N. White & Traudl Krapp-Schickel, 2017

Kristine N. White & Traudl Krapp-Schickel, 2017, Red Sea Leucothoidae (Crustacea: Amphipoda) including new and re-described species, European Journal of Taxonomy 324, pp. 1-40 : 30-36

Paranamixis sommelieri sp. nov.

urn:lsid:zoobank.org:act:0A521B78-39B5-4038-AAC6-ABF049671046

Figs 13–16

Paranamixis bocki – Ledoyer 1967: 125; 1978: 231, fig. 14. — Ruffo 1969: 13.

? Leucothoides pottsi – Ruffo 1959: 2, pl. 1, figs 1–2. — Ledoyer 1967: 127, fig. 5b; 1979b: 111, fig. 68/2.

? Leucothoides torrida – Ledoyer 1986: 682–84, fig. 263.

non Paranamixis bocki Schellenberg, 1938: 29 –30, fig. 14.

Diagnosis

Coxae 2–4 inferior margin thickened and fortified. Gnathopod 2 propodus anterodistal corner with small shallow hump followed by a triangular protrusion of about half width of dactylus, followed by some small triangular knobs along the margin; dactylus curved, reaching about 0.6–0.8 times propodus length, inner margin with two long setae inserted in excavation, after which the dactylus continues abruptly narrowed. Pereopods 5–7 bases widened, not much longer than wide, anterior margin with short setae, posterior margin medially the widest, lower half straight (not concave), upper half rounded. Uropods 1–3 rami unequal.

Etymology

Our friend Ulrich Schiecke always collected with enormous enthusiasm and idealism, content with a minimum of finances and time on disposition. Numerous species have already been dedicated to him, using the genitive of his first or surname. Thus we reflected on the most striking aspects of his character, and settled on one trait for which he is renowned: he is the best connoisseur of Italian wines we know, and the only person who ever dared to send back not one, but three bottles of already opened wine, much to the surprise of the waiters, who were too stunned to protest, but deeply impressed by his sense of taste. The specific name is used as genitive.

Type material

Holotype

SUDAN: ♂ anamorph, 2.8 mm, Port Sudan, stn 168, Dec. 1970, U. Schiecke leg. (ZMB 29753).

Paratype

SUDAN: ♂ leucomorph, 1.4 mm, N of Port Sudan, Flamingo Bay, stn 203, 1 m, sponge, 29 Nov. 1970, U. Schiecke leg. (ZMB 29754).

Additional material examined

SUDAN: 2 leucomorphs, N of Port Sudan, Flamingo Bay, stn 203, 1 m, sponge, 29 Nov. 1970, U. Schiecke leg. (slides MVRCr 7723 and MVRCr 7724); 1 anamorph, Port Sudan, Dec. 1970, U. Schiecke leg.; 30 anamorphs, near Port Sudan, Massa Sheik Ibrahim, stn 168, U. Schiecke leg.; 3 anamorphs, 50 leucomorphs, near Port Sudan, Massa Sheik Ibrahim, stn 173, 14 Dec. 1970, U. Schiecke leg.; 40 leucomorphs, Port Sudan, Marsa Arakiyai, stn 180, Dec. 1970, U. Schiecke leg.; 30 leucomorphs, Port Sudan, Flamingo Bay, stn 188, Dec. 1970, U. Schiecke leg.; 1 anamorph, 1 leucomorph, Port Sudan, stn 196, reef and epiphytes, 12 Nov. 1970, U. Schiecke leg.; 6 leucomorphs, Port Sudan, stn 198, Dec. 1970, U. Schiecke leg.; 1 leucomorph, N of Port Sudan, Flamingo Bay, 1 m, sponge, 29 Nov. 1970, U. Schiecke leg.; ♂ anamorph, 2 mm, near Port Sudan, Massa Sheik Ibrahim, 14 Dec. 1970, U. Schiecke leg. (slide MVRCr 7722).

Description

Male anamorph

LENGTH. 2.8–3 mm.

HEAD. Anterior margin rounded, anterodistal margin notched, distal margin rounded; ventral cephalic keel anterior margin transverse, anteroventral margin rounded, ventral margin straight; eyes present with more than 10 ommatidia, round. Antenna 1 length 0.4 times body length, flagellum 8-articulate, peduncle article 1 width less than 2 times article 2, accessory flagellum absent. Antenna 2 length 0.2 times body length, shorter than antenna 1, flagellum 5-articulate. Mouthparts reduced. Maxilliped inner and outer plates smooth, lacking inner lobes; palp 4-articulate, palp article 4 elongate, slender, strongly recurved.

PErEON. Coxae 1–4 relative widths 1.0: 2.5: 1.5: 1.7. Gnathopod 1 coxa reduced, smooth, bare. Gnathopod 1 absent. Gnathopod 2 coxa longer than broad, much wider than coxa 3, smooth, bare, anterior margin rounded, anterodistal corner with notch, distal margin rounded, posterior margin straight; basis distally expanded, anterior margin with six short setae, posterior margin bare; carpus 0.8 times propodus length, curved, distally tapered, anterior margin smooth; propodus with 1 mediofacial setal row reaching 0.5 times propodus length, 1 submarginal setal row of four setae, posterior margin smooth, palm convex, with one large and several small triangular protrusions and small setae; dactylus curved, reaching 0.5 times propodus length, proximal margin with excavation and two long setae, anterior margin distally tapered, acute. Pereopod 3 coxa length 1.8 times width, anterodistal corner overriding distal face of coxa 2, smooth, anterior margin rounded, distal margin rounded, posterior margin straight. Pereopod 4 coxa smooth, anterior margin rounded, distal margin rounded, posterior margin rounded. Pereopods 5–7 coxae, facial setae absent. Pereopods 5–7 bases width-length ratios 1: 1.3, 1: 1.2, 1:1.2, posterior margins smooth, bare.

PLEON. Epimera 1–3 bare, epimeron 3 posteroventral corner subquadrate. Uropods 1–3 relative lengths 1.0: 1.0: 0.7. Uropod 1 peduncle 0.8 times inner ramus length, outer ramus 0.6 times inner ramus length. Uropod 2 peduncle subequal in length with inner ramus, outer ramus 0.4 times inner ramus length. Uropod 3 peduncle subequal in length with inner ramus, outer ramus 0.8 times inner ramus length. Uropods moderately setose.Telson 1.6 times longer than wide, apex blunt.

Female and male leucomorph

LENGTH. 1.2–1.8 mm.

HEAD. Anterior margin truncate, anterodistal margin subquadrate, distal margin straight; eyes present with about 20 ommatidia, round. Antenna 1 half of body length, flagellum 5-articulate, peduncle article 1 robust, articles 2 and 3 narrower, accessory flagellum absent. Antenna 2 length 0.3 times body length, subequal to antenna 1 length (but geniculate), flagellum 3-articulate. Mandibular palp 2-articulate, article 2 with one distal seta, mandibles with 10 raker spines. Maxilla 1 palp 1-articulate, with 4 distal slender setae; outer plate with 5 distal robust setae. Maxilla 2 inner and outer plates each with 2–3 distal slender setae. Maxilliped outer plate vanishing; palp 4-articulate, article 4 subequal in length with article 3, distally acute.

PErEON. Coxae 1–4 relative widths 1.0: 1.5:0.9: 0.9. Gnathopod 1 coxa smooth, trapezium-shaped, anterodistal margin produced, distal margin straight; basis long and smooth, distally moderately expanded, anterior and posterior margins bare; ischium bare; carpus straight, distally thin, length 14 times width, proximal margin smooth; propodus strongly narrowing distally, palm smooth with many marginal setae; dactylus minute. Gnathopod 2 coxa longer than broad, wider than coxa 3, smooth, anterior margin regularly rounded, anterodistally rounded, distal margin nearly straight, posterior margin straight or somewhat concave; basis not expanded, anterior margin with few short setae, posterior margin bare; ischium bare; carpus 0.4 times propodus length, straight, distally tapered, margins smooth but setose; propodus with 1 mediofacial setal row, with row of submarginal setae, posterior margin smooth, posterior margin triangular, palm with long acute tooth on rectangular palmar corner, with triangular tubercles; dactylus strongly curved, distally acute, margins smooth, bare. Pereopod 3 coxa length 1.5 times width, anterodistal corner overriding distal face of coxa 2, smooth, anterior margin rounded, distal margin slightly rounded, posterior margin straight. Pereopod 4 coxa smooth, similar to coxa 3, anterior margin rounded, distal margin rounded, posterior margin straight. Pereopods 5–7 bases width-length ratios 1: 1.4, 1: 1.3, 1: 1.2, posterior margins rounded, smooth, bare.

PLEON. Epimera 1–3 bare, epimeron 3 posteroventral corner subrectangular. Uropods 1–3 relative lengths 1.0: 0.8: 0.6. Uropod 1 peduncle subequal in length with inner ramus, outer ramus 0.7 times inner ramus length. Uropod 2 peduncle 0.8 times inner ramus length, outer ramus 0.5 times inner ramus length. Uropod 3 peduncle shorter than subequal rami. Uropods 1–3 rami with robust setae. Telson 1.6 times longer than wide, with 2 distal and one marginal setae, apex bluntly rounded.

Remarks

The only species of Paranamixis cited until now from the Red Sea is P. bocki Schellenberg, 1938 ( Ruffo 1969) . Ruffo (loc. cit.) discussed two specimens only verbally and ascribed them to the material published by Ledoyer (1967). Schellenberg (1938) illustrated from his single specimen of 3 mm (from the Gilbert Islands, Central Pacific) an elliptical coxa 2 with a sharp protruding rectangular tooth, while Ledoyer’s drawings (no length of the specimen indicated) show a subquadrate coxa 2 with a small incision on the anterior margin. Coxa 2 as figured by Ledoyer (1967: fig. 5) is malformed in the upperleft corner of the sketch of the head; it also seems clear that the rostrum is not as acute as it is drawn. Ledoyer (1978) compared the material from Tuléar (Madagascar) published in 1967 with his specimens from Mauritius and thought that both belonged to the same species, but the attribution to P. bocki is cited with a question mark. Thomas (1997) repeated this doubt: he cited the original description of P. bocki by Schellenberg but did not attribute the material of Ledoyer (1967, 1978) to this species. There is also a quite different gnathopod 2 propodus (in Schellenberg’s illustration without the characteristic triangular protrusion on propodus anterodistal corner), but this could be due to allometry, as only small and shallow humps instead of strikingly prominent ones were also observed in our material sometimes. However, the difference in the coxa 2 shape is too strong to be changed with age.

Thomas (1997) described P. clarkae from the Seychelles, and illustrations of his material (length 2.7– 3.15 mm) bear quite a good resemblance to material studied herewithin. The major difference is the posterior margin of pereopod bases 5 and 6, which is clearly excavated in the inferior half vs straight in our material. Thomas (1997) compared his material with P. excavatus Ledoyer, 1978 from Mauritius, but here we find clear differences: coxa 2 again shows the blunt corner followed by a short concave margin similar to P. bocki , and uropod 3 has subequal rami. Paranamixis madagascariensis Ledoyer, 1982 has quite small eyes and a regularly rounded coxa 2, similar to P. indicus Sivaprakasam, 1968 in the illustration of the holotype, where gnathopod 2 dactylus also has a deep excavation on the proximoinferior half; figures of males from station 4 fit well to our material, showing the blunt corner on coxa 2 antero-distal margin and no excavation on the dactylus.

Ecology

This species was collected among sponges.

Distribution

Red Sea (present study).

Figures

Fig. 13. Paranamixis sommelieri sp. nov., holotype, anamorph ♂, length 2.8 mm (ZMB 29753).

Fig. 14. Paranamixis sommelieri sp. nov., holotype, anamorph ♂, length 2.8 mm (ZMB 29753).

Fig. 15. Paranamixis sommelieri sp. nov., paratype, leucomorph ♂, length 1.4 mm (ZMB 29754).

Fig. 16. Paranamixis sommelieri sp. nov., paratype, leucomorph ♂, length 1.4 mm (ZMB 29754).