Caridina neglecta, Cai & Ng, 2007

Cai, Y. & Ng, P. K. L., 2007, A revision of the Caridina gracilirostris De Man, 1892, species group, with descriptions of two new taxa (Decapoda; Caridea; Atyidae), Journal of Natural History 41 (25 - 28), pp. 1585-1602 : 1595-1599

Caridina neglecta new species

( Figures 4 , 5 )

Material examined

Holotype: male, cl 4.2 mm, MZB, Sungai Batang, 13 km on road from Palopo to Wotu, Sulawesi, Indonesia, coll. M. Kottelat and A. Werner, March 1989 . Paratype: one female, cl 4.3 mm, ZRC, same data as holotype .

Other material. Two males, cl 2.2–4.3 mm, ZMA De 102647, paralectotypes of Caridina gracilirostris De Man, 1892 , river near Reo, Flores, Indonesia, coll. M. Weber, 1888 ; one male, cl 5.3 mm, one female, cl 4.2 mm, USNM 285309 , Baganga River , Mindanao, Philippines, coll. Albatross Philippines Expedition, 13 May 1908 .

Description

Rostrum ending in bifid top, reaching far beyond distal end of scaphocerite, about 1.5–2.0 times as long as carapace, strongly upturned, armed with four to eight dorsal teeth on posterior half and 21–30 teeth along whole ventral margin; antennal spine short, situated below inferior orbital angle; pterygostomial margin sub-rectangular.

Sixth abdominal somite 0.6 times as long as carapace, 1.8 times as long as fifth somite, slightly shorter than telson. Telson 3.8 times as long as wide, with three or four pairs of dorsal spinules and one pair of dorsolateral spinules; distal spines short, stout, lateral pair slightly longer than intermediate spines; not ending in a posteromedian projection. Preanal carina with spine.

Eyes well developed, anterior end reaching to 0.7 times length of basal segment of antennular peduncle. Antennular peduncle 0.8 times as long as carapace; basal segment of antennular peduncle longer than sum of second and third segment lengths; second segment distinctly longer than third segment. Stylocerite reaching to 0.8 times length of basal segment of antennular peduncle or near end of this segment. Scaphocerite very slender, 4.2 times as long as wide.

Incisor process of mandible ending in irregular teeth, molar process truncate. Lower lacinia of maxillula broadly rounded, upper lacinia elongate, with numerous distinct teeth on inner margin, palp slender. Upper endites of maxilla subdivided, palp short, scaphognathite tapering posteriorly with some long, curved setae at posterior end. Palp of first maxilliped ending in finger-like projection. Second maxilliped typical of genus. Third maxilliped reaching near end of antennular peduncle, with ultimate segment distinctly shorter than penultimate segment.

Epipods on first four pereiopods. First pereiopod reaching beyond end of eye stalk; merus 3.2–4.0 times as long as broad; carpus slightly longer than merus, 2.3–2.9 times as long as high; chela 2.6 as long as broad, fingers 1.2–1.4 times as long as palm. Second pereiopod reaching beyond end of basal segment of antennular peduncle, merus shorter than carpus, 5.8–6.1 times as long as broad; carpus 1.3–1.4 times as long as chela, 6.2–6.7 times as long as high; chela 2.8–3.0 times as long as broad; fingers 1.3 times as long as palm. Third pereiopod reaching to end of antennular peduncle, propodus 11 times as long as wide, 4.1–5.1 times as long as dactylus; dactylus 2.6 times as long as wide, with six teeth on flexor margin. Fifth pereiopod reaching to end of third segment of antennular peduncle, propodus 15 times as long as wide, 3.7–3.8 times as long as dactylus; dactylus 3.7 times as long as wide, with 37–44 spinules on flexor margin.

Endopod of male first pleopod subtriangular, about 0.25 times as long as exopod, with appendix interna.

Uropodal diaeresis with nine movable spinules.

Eggs 0.4× 0.25 mm in diameter.

Habitat

Rivers.

Etymology

The species name neglecta alludes to the fact that it has long been neglected as a valid taxon.

Distribution

Known only from Indonesia and Philippines so far, but considering these records, it probably has a wider range.

Remarks

The presence of an appendix interna on the endopod of the male first pleopod easily separates C. neglecta from C. gracilirostris and C. gracilima .

Figures

Figure 4. Caridina neglecta, new species. (A, C) Cephalothorax and cephalic appendages; (B) first pereiopod, female; (D) first pereiopod, male; (E) second pereiopod, male; (F) third pereiopod; (G) dactylus of third pereiopod; (H) fifth pereiopod; (I) dactylus of fifth pereiopod; (J) endopod of male first pleopod; (K) appendix masculina and appendix interna of male second pleopod; (L) preanal carina; (M) second pereiopod, female. (A, B, M) Female, paratype, cl 4.3 mm, ZRC; (C–L) male, cl 4.2 mm, holotype, MZB, Sungai Batang, 13 km on road from Palopo to Wotu, Sulawesi, Indonesia. Scale bars: 1 mm (A, C); 0.5 mm (B, D–F, H, M, L); 0.2 mm (J, K); 0.1 mm (G, I).

Figure 5. Caridina neglecta, new species. (A) Cephalothorax and cephalic appendages; (B) telson; (C) distal portion of telson; (D) first pereiopod; (E) second pereiopod; (F) third pereiopod; (G) fifth pereiopod; (H) preanal carina; (I) diaeresis. Male, cl 5.3 mm, USUM 285309, Baganga River, Mindanao, Philippines. Scale bars: 1 mm (A), 0.5 mm (B, D–G), 0.2 mm (C, I).