Caridina rubella Fujino & Shokita, 1975

Mazancourt, Valentin de, Marquet, Gérard & Keith, Philippe, 2024, An Integrative Taxonomic Revision of the Freshwater Atyid Shrimps (Crustacea: Decapoda: Caridea) of Micronesia, Diversity 16 (200), pp. 1-31 : 21-22

Caridina rubella Fujino & Shokita, 1975

Figure 3F .

- Caridina rubella Fujino and Shokita, 1975: 102 , Figure 6 [type locality: Izaga Cave, Miyako Island, Ryukyu, Japan].—Shokita and Nishijima, 1976 [52]: 71.—Shokita, 1979 [53]: 203; 2003 [54]: 250, Figures 18F and 19I; 2006 [55]: 61.—Maciolek, 1983 [25]: 607.—Cai and Anker, 2004 [56]: 243, Figures 6 and 7 .—Fujita and Shokita, 2005 [57]: 203.—Cai and Shokita, 2006 [51]: 2145, Figures 6F–J , 7 and 8 .—Fujita, 2007 [58]: 92; 2018: 16.—Cai and Ng, 2009 [59]: 1094.—Weese et al., 2012 [60]: 109.—De Grave et al., 2022 [61]: 711, Figures 1 and 2 .

- Caridina sp. 1 —Marquet et al., 2003 [62]: 74.

Material examined

GUAM. ZMB 34612 : 1 ♀, Fai Fai Cave , 13 ◦ 31.700 ′ N, 144 ◦ 48.233 ′ E, coll. D.C. Rogers .

Distribution

This species has a wide distribution in anchialine habitats in the Pacific: Japan (Ryukyu), Philippines (Bohol, Palawan, Panglao), Indonesia (Sulawesi), New Caledonia (Loyalty), Cook Islands, French Polynesia (Tahiti), Niue, Tonga (Tongatapu), Western Samoa (Upolu), Solomon Islands (Nggela Pile), and Guam.

Remarks

The single female specimen collected from Fai Fai Cave in Guam agrees well with the published descriptions of the species [51,61,63], having a rostral formula of 10 + 28/12 and a rostrum 1.19 times as long as the carapace. Interestingly, our sequence clusters with a 16S sequence of the short-rostrum morph of the species from Miyako Island which is thought to represent the “real” C. rubella , whereas the long-rostrum morph from the same area potentially represents an undescribed species [60]. Consequently, it appears that this species is morphologically variable, as recently illustrated by De Grave et al. [61], but probably hides cryptic species. Amolecular study of this species from its whole range would be needed to clarify its status.

Figures

Figure 1. Map of Micronesia with the three surveyed islands circled in red.

Figure 2. Rivers and sites surveyed in Babeldaob, Guam, and Pohnpei (dots: prospected sites).

Figure 3. Phylogenetic tree of the atyid species from Micronesia obtained by Bayesian inference from the 16S rRNA. Numbers above branches indicate Bayesian posterior probabilities, numbers under branches indicate maximum likelihood bootstraps. Letters A–K for the clades refer to the species listed in the taxonomic account.

Figure 6. Caridina lobocensis. (a) first pereiopod; (b) second pereiopod; (c) third pereiopod; (d) fifth pereiopod; (e) dactylus of third pereiopod; (f) dactylus of fifth pereiopod; (g) telson; (h) undeveloped eggs; (i) uropodal diaeresis; (j) pre-anal carina; (k) cephalothorax. MNHN-IU-2024-459 (DNA: CA1555): a, b, j, and k; MNHN-IU-2024-455 (DNA: CA1552): d and f; MNHN-IU-2024-456 (DNA: CA1553): g, h, and i; MNHN-IU-2024-460 (DNA: CA1556): c and e.

Figure 7. Caridina cf. serratirostris. Lateral view of the single ovigerous female, MNHN-IU-2024-461 (DNA: CA1245).

Figure 8. Caridina rintelenorum sp. nov. (a) first pereiopod; (b) second pereiopod; (c) third pereiopod; (d) fifth pereiopod; (e) dactylus of third pereiopod; (f) dactylus of fifth pereiopod; (g) uropodal diaeresis; (h) telson; (i) pre-anal carina; (j) undeveloped eggs; (k) cephalothorax. Holotype: MNHN- IU-2024-462 (DNA: CA1864): a–g and i–k. Paratype: MNHN-IU-2024-463 (DNA: CA2534): h.