Linguimaera bogombogo, Krapp-Schickel, 2003

Krapp-Schickel, T., 2003, Linguimaera Pirlot, 1936 (Crustacea, Amphipoda, Melitidae), a valid genus, Memoirs of Museum Victoria 60 (2), pp. 257-283 : 261-265

Linguimaera bogombogo sp. nov.

Figures 3–4

Maera hamigera . — Barnard, 1965: 507–510, fig. 16.

? Maera species A .— Barnard, 1970: 158, fig. 98, 99

(not Maera hamigera Haswell, 1879a: 333 , pl. 21 fig. 1)

Material examined. Holotype. Eniwetok Atoll , Bogombogo Island, Micronesia, USNM 108926 (male, 4.3 mm).

Paratype. Eniwetok Atoll , Bogombogo Island, Micronesia, USNM 108926 (ovigerous female, 5.2 mm) .

Other material. Eniwetok Atoll, Igurin I., lagoon side, alga Bryopsis sp. , attached to rocks, 27 Sep 1956, USNM 108928 (male 5 mm, drawn by Barnard, 1965; 2 ovigerous females 5 mm, 4.3 mm, immature and juvenile, incomplete). Igurin I., lagoon side, preserved rocks, 27 Sep 1956, USNM 108949 (1 juvenile). Igurin I., lagoon side, sand washings from under rocks, 27 Sep 1956, USNM 108927 (1 male? 3.5 mm, 1 specimen 3 mm, 3 juveniles). Boden I., ocean side, 12 Oct 1956, USNM 108929 (1 specimen 3.3 mm)..

Diagnosis. Gnathopod 1 propodus rectangular, twice as long as wide, palm oblique, straight. Gnathopod 2 male palm well defined as acute tooth, followed by V-shaped incision; palm with small shallow excavations. P7 rectangular, widened and posterodistally lengthened, ratio length: width = 1.5. Telson with 1 distal strong robust seta of about one third of telson length.

Description. Ovigerous female 5–5.5 mm, male 4–5 mm.

Head about same length as first 2 body segments. Lateral cephalic lobes rounded, with notch, anteroventral corner rounded. Eyes narrowed in middle.

Antenna 1 about 0.6 body length, peduncle = flagellum, peduncle article 1 shorter than article 2; flagellum of up to 25 articles, accessory flagellum of 3–4 articles; antenna 2 slender, gland cone reaching about half of peduncle article 3, article 4 longer than article 5, flagellum longer than peduncle article 5, of 8 articles.

Mandibular palp article 1 clearly longer than wide; ratio article 2: article 3 = 1.4, article 2 with 4 long setae, article 3 distally 4 setae, laterally 2–3.

Gnathopod 1 not sexually dimorphic. Coxa 1 anterodistally lengthened and pointed. Basis ratio length: width = 3, posteriorly 5-6 long setae. Merus posteroventrally rounded, characteristical pointed tooth lacking, ratio length: breadth less than 2; carpus triangular, ratio length: breadth= 2.3; propodus rectangular, less broad than carpus, ratio length: breadth= 2.3, palm defined, oblique.

Gnathopod 2 of female slightly dimorphic in size and shape. Coxa 2 quadrangular, basis with few long setae on posterior margin, merus posterodistally with tooth; carpus triangular, ratio length: breadth= 1.45, carpus: propodus = 0.55, both about same width; propodus slender, similar shape to male, but narrower; anterior and posterior margin parallel, palm defined by prominent tooth and beset with strong robust setae, anterior: posterior margin = 4:3. Smaller gnathopod 2 lacking prominent defining tooth, longer and narrower. Gnathopod 2 of male strongly dimorphic, carpus in larger gnathopod shorter, length subequal to width. Both propodi similar to female, but larger one more broadened and defining tooth as well as robust seta sitting next to it more developed.

Pereopods 3, 4 similar in shape and size. Pereopods 5–7 robust, basis rounded, very small serrations on posterior margins. Pereopod 6 the longest, in pereopod 7 the propodus shortened and thickened. Dactylus with uneven outer and inner margins, distally on inner one 1 stiff seta and one short and thin next to it.

Epimeral plate 3 with small dense serration.

Uropod 1 peduncle inferior margin on proximal third with 1 strong robust seta, subequal rami shorter than peduncle; uropod 2 subequal rami shorter than peduncle; uropod 3 rami subequal distally rounded, beset with many robust setae being maximally of a quarter of ramuslength.

Telson longer than wide, lobes outer end longer than inner one; in excavation 1 strong robust seta inserted, about one third of telson length. Outer margin about halfways another, somewhat shorter robust seta, distally 1-2 fine setae, proximally a stiff robust seta.

Etymology. From the island where the type specimens were found (noun in apposition).

Distribution. Eniwetok Atoll ( Micronesia); green algae ( Bryopsis, Caulerpa, Halimeda ) and surrounding sand of rocky intertidal; wash of old coral heads in about one-third metre of water, together with amphipods Cymadusa filosa , Elasmopus pseudaffinis, Gammaropsis digitatus, G. pacificus, Lembos aequimanus, L. bryopsis , L. cf. intermedius , Quadrimaera serrata , Mallacoota cf. insignis, Paragrubia vorax.

Discussion. This species clearly belongs to this clade, having bean-shaped eyes, a (not very pronounced, but present) notched cephalic lobe, mandibular palp article 3 much shorter than article2, coxa 1 anteriorly acutely lengthened, gnathopod 1 carpus thickened, gnathopod 2 asymmetrical, epimeral plates 1–3 with characteristic excavations or serrations, uropod 3 rami long and with many short robust setae, telsonic lobes distally incised.

Figures

Figure 3. Linguimaera bogombogo sp. nov., male, female (Eniwetok Atoll, Bogombogo Island, Micronesia). Hd, Gn1, U3 in scale = 0.33 mm; Mdp, UL, T in scale = 0,175 mm.

Figure 4. Linguimaera bogombogo sp. nov, male, female (Eniwetok Atoll, Bogombogo Island, Micronesia). Gn2 female in scale = 0.25 mm; Gn2 male, Gn2´female in scale = 0.125 mm; P6, 7 in scale = 0.175.