Caridina yapenensis, Cai, 2025

Cai, Yixiong, 2025, Validation of two species of Caridina (Decapoda: Atyidae) from New Guinea, Zootaxa 5660 (2), pp. 290-292 : 291

Caridina yapenensis sp. nov.

Caridina yapenensis Cai, 2025: 25 , figs. 12, 13. [unavailable]

Material examined. Holotype: Female, cl 5.8 mm, RMNH 700 , creek near Seroei , Yapen Island, Papua, Indonesia, 22 February 1955.

Description. Rostrum reaching far beyond distal end of scaphocerite, as long as carapace, strongly upturned, unarmed dorsally, armed ventrally with four large teeth; antennal spine short, situated below inferior orbital angle; pterygostomial margin subrectangular.

Sixth abdominal somite 0.62 times as long as carapace, 1.6 times as long as fifth somite, as long as telson. Telson very slender, ending in a distinct triangular, 3.9 times as long as wide, with four pairs of dorsal spinules and one pair of dorsolateral spinules: distal spines very stout, lateral pair distinctly longer than intermediate spines. Preanal carina with a distinct spine.

Anterior end of eye reaching 0.7 length of basal segment of antennular peduncle. Antennular peduncle 0.76 times as long as carapace; anterolateral angle of basal segment reaching 0.20 length of the second segment. Stylocerite long, reaching to slightly beyond middle of second segment of antennular peduncle. Scaphocerite 3.4 times as long as wide.

Palp of first maxilliped ending in a finger-like projection. Third maxilliped reaching to middle of second segment of antennular peduncle, with ultimate segment distinctly shorter than penultimate segment.

First pereiopod reaching beyond end of eye stalk; merus longer than carpus, 2.9 times as long as wide, carpus 1.4 times as long as high; chela twice as long as broad, fingers slightly longer than palm. Second pereiopod reaching to end of second segment of antennular peduncle, merus as long as carpus, 5.7 times as long as broad; carpus 1.2 times as long as chela, 4.4 times as long as high; chela 2.6 times as long as broad; fingers 1.6 times as long as palm. Third pereiopod reaching to end of scaphocerite, with propodus 12 times as long as wide, 5.3 times as long as dactylus; dactylus 3.0 times as long as wide (spines included), with five spines on flexor margin. Fifth pereiopod reaching to middle of second segment of antennular peduncle, with propodus 16 times as long as wide, 5.5 times as long as dactylus; dactylus 2.7 times as long as wide, with 39 spinules on flexor margin.

Uropodal diaeresis with 17 movable spinules

Etymology. The species is named after the type locality, Yapen Island, Papua, Indonesia.

Remarks. Please refer to Cai (2025) for detailed figures, habitat, distribution and morphological comparison of Caridina yapenensis to its congeners.