Linguimaera garitima, 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 : 266

Linguimaera garitima sp. nov.

Figures 5–7

Material examined. Holotype. Australia. Tasmania, eastern Bass Strait, 82 km ENE of North Point, Flinders I. (39˚27.7´S, 148˚41.4´E), 293 m, coarse sand, naturalist’s dredge, G.C.B. Poore on HMAS Kimbla , 28 Mar 1979 (stn BSS 36), NMV J52321 (1 male 7 mm).

Paratype. Collected with holotype, NMV J52322 (1 female 7 mm) .

Other material. Collected with holotype, NMV J20371 (8 males, 16 females 17 juveniles) .

Diagnosis. Similar to L. leo sp. nov. but: body smaller, articles narrower, coxa 1 anterodistally more lengthened and anteriorly excavated, gnathopod 1, 2 propodus rectangularly narrow, setae long, gnathopod 2 male the smaller ones similar to gnathopod 2 female in totally lacking palmar tooth; pereopod 7 basis about twice as long as wide. Telson about as long as wide, distal strong robust seta between half and two thirds of telsonlength.

Description. Adult male, female 5.5–8 mm.

Head: lateral cephalic lobes rounded, anteroventral corner rectangular. Eyes more than twice as long as large, upper part narrowed.

Antenna 1 peduncle scarcely longer than flagellum, peduncle article1 shorter than article 2; flagellum of up to 34 articles, accessory flagellum of 6 articles; antenna 2 gland cone short, article 4 longer than article 5, flagellum subequal to peduncle article 5, of 9 articles.

Mandibular palp article 1 longer than wide; article 2: article 3 = 1.6, both with long setae, article 3 also distally.

Coxa 1 anterodistally acute and anteriorly excavated; gnathopod 1 propodus narrow, more than twice as long as wide.

Gnathopod 2 of female with narrow and long propodus lacking a defining tooth on the palmar corner, with palm oblique, crenulate. Gnathopod 2 of male propodus palm almost transverse, blunt robust defining tooth on (about rectangular) palmar corner; ratio of propodi gnathopod 1: gnathopod 2 = 0.5.

Pereopods 3, 4 merus not widened; female pereopod basis narrower.

Uropod 1 peduncle as long as rami.. Uropod 3 rami with thinner robust setae.

Telsonic lobes with long robust seta which is clearly longer than half telsonlength.

Etymology. During my stay at Museum Victoria, Melbourne, Gary Poore and Tim O’Hara were extremely helpful on many occasions, and furthermore were strongly involved in the collection of the material. The specific epithet is a combination of their names and expresses my gratitude; used as an adjective.

Distribution. Bass Strait, coarse shell, 293 m.

Discussion. This clade seems strikingly conservative and though checking very thoroughly, there are not many easy characters separating this species from the much shallower L. leo (if not dealing with mature males), except: much greater depth, smaller body size, mandibular palp ratio article 2 to article 3 longer (1.65 vs 1.8 in L. leo ), palmar corner of male gnathopod 2 with about right angle (vs oblique) and (most reliable character) a long robust seta on telsonic lobes (much shorter in L. leo ).

Figures

Figure 5. Linguimaera garitima sp. nov. (Tasmania). Habitus in scale = 1 mm; Gn1, Gn2 male large and Ep3 in scale = 0.4 mm; Gn2´male large in scale = 0.2 mm.

Figure 6. Linguimaera garitima sp. nov. (Tasmania). Mx1, 2; Md, LL, T´ in scale = 0.25 mm; P3, 4, 6 in scale = 1.25 mm; Gn2 small male, U3, T in scale = 0.5 mm.

Figure 7. Linguimaera garitima sp. nov. (Tasmania). Gn2 male large, Gn2 male small; U1, U3 male, P7´female 8.5 mm in scale = 0.5 mm; Gn2 female, P5–7 female in scale = 1.25 mm.