Caridina longifrons, 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 : 1599-1601

Caridina longifrons new species

( Figure 6 )

Material examined

Holotype: male, cl 4.5 mm, MZB, Kabupaten Maros, stream above Bantimurung waterfall, Sulawesi, Indonesia, coll. M. Kottelat, 7 July 1988 . Paratypes: seven males, cl 3.8–4.3 mm, three females, cl 4.6–5.0 mm, eight ovigerous females, cl 4.7–5.2 mm, ZRC, data same as holotype .

Description

Rostrum ending in bifid tip, reaching far beyond distal end of scaphocerite, about twice as long as carapace, strongly upturned, armed with 8–11 dorsal teeth on posterior half, including none to two postorbital teeth, with 26–33 teeth along whole ventral margin; antennal spine short, situated below inferior orbital angle; pterygostomian margin broadly rounded.

Sixth abdominal somite 0.8 times as long as carapace, 2.1 times as long as fifth somite, slightly longer than telson. Telson 3.1 times as long as wide, with four or five pairs of dorsal spinules and one pair of dorsolateral spinules; distal spines short, stout, lateral pair slightly longer than intermediate spines; lacking 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; anterolateral angle pointed, reaching 0.3 times length of second segment, 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 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 to end of eye stalk; merus 2.0 times as long as broad; carpus slightly longer than merus, 1.8 times as long as high; chela 2.1 times as long as broad, fingers 1.2 times as long as palm. Second pereiopod reaching to end of basal segment of antennular peduncle, merus shorter than carpus, 2.9 times as long as broad; carpus as long as chela, 3.6 times as long as high; chela 2.5 times as long as broad; fingers 1.4 times as long as palm. Third pereiopod reaching to third segment of antennular peduncle, propodus 11 times as long as wide, 4.0 times as long as dactylus; dactylus 3.4 times as long as wide (spines included), with eight spines on flexor margin. Fifth pereiopod reaching to second segment of antennular peduncle, propodus 11 times as long as wide, 3.5 times as long as dactylus; dactylus 3.6 times as long as wide, with 41 spinules on flexor margin.

Endopod of male first pleopod sub-rectangular, about 0.2 times as long as exopod, without appendix interna.

Uropodal diaeresis with nine movable spinules.

Eggs 0.9–1.0× 0.42–0.45 mm.

Habitat

Caridina longifrons was found in mountain streams above Bantimurung waterfall (M. Kottelat, personal communication).

Etymology

The species name is a combination of two Latin roots, long, for lengthy, and frons, forehead, alluding to the form of the extra long rostrum. The name is used as a noun in apposition.

Distribution

Known only from the type locality, Maros of southern Sulawesi, Indonesia .

Remarks

Caridina longifrons superficially resembles C. gracilirostris . However, it can be easily separated from allied species by its relatively larger eggs. It can also be differentiated from C. gracilirostris by its relatively stouter telson (3.1 times as long as wide versus 4.8 times), the more slender merus of the first pereiopod (2.5 times as long wide versus 2.0 times), the shorter carpus of the second pereiopod (as long as chela versus 1.2 times longer than chela), and the stouter carpus of the second pereiopod (3.6 times as long as high versus 4.0 times).

Figures

Figure 6. Caridina longifrons. (A) Cephalothorax and cephalic appendages; (B) telson; (C) distal portion of telson; (D) antennular peduncle; (E) scaphocerite; (F) first pereiopod; (G) second pereiopod; (H) third pereiopod; (I) dactylus of third pereiopod; (J) fifth pereiopod; (K) dactylus of fifth pereiopod; (L) endopod of male first pleopod; (M) appendix masculina and appendix interna of male second pleopod; (N) diaeresis; (O) preanal carina; (P) egg. (A–K, O, P) Female, cl 5.0 mm; (L, M) male, cl 4.0 mm, ZRC, above Bantimurung waterfall, Kabupaten Maros, Sulawesi, Indonesia. Scale bars: 1 mm (A, D, E); 0.5 mm (B, F–H, J, O, P); 0.2 mm (C, I, K, L–N).