Brevitalitrus kumanoi, Miyamoto & Morino, 2012

Miyamoto, Hisashi & Morino, Hiroshi, 2012, Taxonomic Studies on the Talitridae (Crustacea: Amphipoda) of Taiwan. V. The Genus Brevitalitrus Bousfield, 1971, Species Diversity 17 (2), pp. 187-200 : 193-198

publication ID	https://doi.org/ 10.12782/sd.17.2.187
publication LSID	lsid:zoobank.org:pub:73324AD6-B3B0-4A48-B4E0-7EA3E54D234A
persistent identifier	https://treatment.plazi.org/id/A076DD1C-6ECC-4C93-B5B3-7E278DA2FC36
taxon LSID	lsid:zoobank.org:act:A076DD1C-6ECC-4C93-B5B3-7E278DA2FC36
treatment provided by	Felipe
scientific name	Brevitalitrus kumanoi
status	sp. nov.

Treatment

Brevitalitrus kumanoi sp. nov.

( Figs 7–11 View Fig View Fig View Fig View Fig View Fig )

Material examined. Holotype: female (7 mm),

NSMT-Cr 9109, Kenting , southern Taiwan, 21°56′N, 120°48′E, 10 August 1981 GoogleMaps . Paratypes: 2 females (6, 7 mm), NSMT-Cr 9111, same data as holotype; 5 females (5–8 mm), NMNS-6545-002, same data as holotype; 2 females (6, 7 mm), NSMT-Cr 9110, Lanyu Island , 22°02′N, 121°30′E, 26 July 1979; 5 females (5–7 mm), same locality, 3 August 1981, NMNS-6545-001 GoogleMaps . The present species was found un- der fallen leaves and rocks, and among roots of Pandanus sp.

Description. Female (holotype). Antenna 1 ( Fig. 8A View Fig ) long, flagellum 6-articulated. Antenna 2 ( Fig. 8B View Fig ) 0.6 times as long as body length, peduncular article 5 subequal in length to articles 3 and 4 combined; flagellum 16-articulat- ed.

Maxilla 1 ( Fig. 8G, H View Fig ) with outer plate dentition formula 0-1-3-4-4-3-3-3-3. Maxilla 2 ( Fig. 8I, J View Fig ) with outer plate bearing 11 blunt spines on edge ( Fig. 8I View Fig , bl), 8 setulose sharp spines on dorsal side ( Fig. 8I View Fig , st), and 12 brushy sharp spines on ventral side ( Fig. 8J View Fig , br); inner plate with 9 blunt spines on oblique edge, 2 brushy sharp spines and 3 setulose sharp spines on ventral side, and 3 setulose sharp spines and 2 pappose spines on dorsal side ( Fig. 8I View Fig , pp). Maxilliped ( Fig. 8K, L View Fig ) with palp article 3 bearing a few short, fine setae on proximal part of inner margin, ventral surface with 4 spines on inner distal corner ( Fig. 8O View Fig ), with 3 spines on distal part of surface, dorsal surface ( Fig. 8L View Fig ) with 4 spines on inner distal corner and 2 spines distally; palp article 4 with 5 spines apically.

Gnathopod 1 ( Fig. 9A–C View Fig ) with basis bearing 5 spines on anterior margin, 2 spines on posterodistal corner; carpus with a few long sheathed spines on medial surface ( Fig. 9C View Fig , sh); propodus 0.7 times as long as carpus, with 4 bifid spines along posterior margin ( Fig. 9C View Fig , bf), and with 4 long sheathed spines on lateral surface ( Fig. 9B View Fig , sh) and 4 short sheathed spines on medial surface ( Fig. 9C View Fig , sh); dactylus 0.5 times as long as propodus. Gnathopod 2 ( Fig. 9E View Fig ) with broad coxal plate, posterior cusp knob-like; merus subequal in length to ischium, lacking blister-shaped swelling; carpus 1.7 times as long as merus; propodus 0.9 times as long as carpus; dactylus ( Fig. 9F View Fig ) with imbricated spine on grasping margin.

Pereopods 3 and 4 each with long, acute posterior cusp on coxal plate. Pereopod 3 ( Fig. 10A View Fig ) with carpus 2.5 times as long as wide; propodus 1.4 times as long as carpus. Pereopod 4 ( Fig. 10B View Fig ) with carpus 2.6 times as long as wide; propodus 1.3 times as long as carpus; dactylus ( Fig. 10J View Fig ) hardly notched. Pereopod 5 ( Fig. 10C View Fig ) subequal in length to pereopod 3; anterior lobe of coxal plate much broader (ca. 2.0 times) and slightly deeper (ca. 1.2 times) than posterior lobe; basis narrowing distally. Pereopods 6 and 7 each with propodus 1.3 times as long as carpus; dactylus ( Fig. 10L, M View Fig ) 0.3 times as long as propodus. Pereopod 6 ( Fig. 10D View Fig ) 1.5 times as long as pereopod 3; basis ovate, lacking posterodistal lobe; propodus subequal in length to basis. Pereopod 7 ( Fig. 10E View Fig ) 1.6 times as long as pereopod 3; basis narrowing distally, posterodistal margin weakly serrated, posterodistal lobe hardly incised at junction with ischium; propodus longer than basis, distal spine long, 0.25 times as long as dactylus ( Fig. 10M View Fig ).

Coxal gill of pereopod 6 ( Fig. 10N View Fig ) spatula-shaped, distal end exceeding ischium.

Epimeral plate 1 ( Fig. 11A View Fig 1 View Fig ) with convex posterior margin. Epimeral plates 2 and 3 ( Fig. 11A View Fig 2 View Fig , A 3 View Fig ) each gently curved from anterodistal corner of ventral margin to posterodistal corner; posterior margin gently convex, with a few minute spines.

Pleopods 1–3 each with 2 coupling hooks on inner distal corner of peduncle ( Fig. 11E View Fig ). Pleopod 2 ( Fig. 11C View Fig ) subequal in length to pleopod 1 ( Fig. 11B View Fig ); peduncle with plumose seta; inner ramus 0.7 times as long as peduncle, 4-articulated. Pleopod 3 ( Fig. 11D View Fig ) 0.7 times as long as pleopod 2; peduncle subequal in width to that of pleopod 2, with plumose seta on outer margin and 4 spines on surface; rami 0.5 times as long as peduncle, inner ramus subequal in length to outer ramus, 3-articulated.

Uropod 1 ( Fig. 11F View Fig ) with outer ramus 0.8 times as long as peduncle, lacking marginal spines, inner ramus subequal in length to outer ramus, with 4 marginal spines. Uropod 2 ( Fig. 11G View Fig ) 0.6 times as long as uropod 1; inner ramus subequal in length to peduncle, with 3 marginal spines; outer ramus 0.8 times as long as inner ramus, lacking marginal spines. Uropod 3 ( Fig. 11H View Fig ) shorter than telson, 0.2 times as long as uropod 1; peduncle narrowing distally; ramus 0.3 times as long as peduncle, with 1 short and 2 long spines terminally ( Fig. 11I View Fig ). Telson ( Fig. 11J View Fig ) narrowing distally, each lobe with bifid spine terminally.

Oostegite of gnathopod 2 ( Fig. 9E View Fig ) with 8 simple-tipped setae on distal margin.

Remarks. Only females were available for examination, and therefore the following comparison is limited to females. Brevitalitrus kumanoi sp. nov. is most similar to B. nesius and B. toli in having the flagellum of antenna 2 being 14–16 articulated, the outer rami of uropods 1 and 2 both lacking marginal spines, and the propodus of pereopod 6 subequal in length to the basis. The new species is distinguished from B. nesius by the following features: (1) posterodistal lobe of basis of pereopod 7 barely incised at junction with ischium (vs distinctly incised); (2) posterior margin of epimeral plate 3 gently convex (vs sinuous); and (3) distolateral spine of uropod 1 simple (vs having a projecting terminal capillary and a terminal cap). The new species differs from B. toli in the following characters: (1) propodus of gnathopod 2 extending straight out at distal end (vs upturned at distal end); (2) posterior margin of basis of pereopod 7 almost straight (vs convex); (3) rami of pleopods 1 and 2 shorter than respective peduncles, 4-articulated (vs longer than peduncles, 7–9 articulated); and (4) rami of pleopod 3 3-articulated (vs uniarticulated).

This new species is easily distinguished from B. hortulanus , the other congeneric species known from Taiwan, in the following features: (1) coxal gill of pereopod 6 spatula-shaped of the uniform breadth (vs expanded distally); (2) peduncle of pleopod 3 subequal in width to those of pleopods 1 and 2 (vs wider), and with spines on surface (vs lacking spines); and (3) outer ramus of uropods 1 and 2 lacking marginal spines (vs having marginal spines).

Distribution. Known only from Kenting and Lanyu Island, Taiwan.

Etymology. This new species is dedicated to the late Prof. Masao Kumano of Kanazawa Normal College, who was the first author’s professor in systematic zoology.