Caridina pagei, Christodoulou & Grave, 2023

Christodoulou, Magdalini & Grave, Sammy De, 2023, Redescription of Caridina sobrina Riek, 1953 stat. nov. and description of a new species of Caridina from south-eastern Queensland (Decapoda, Atyidae), Zootaxa 5353 (6), pp. 582-594 : 590

Caridina pagei n. sp.

( Fig. 5 )

Caridina indistincta sp. C1 Page & Hughes, 2007a: 225.

Type material. Female holotype (pocl 3.5 mm), Honeyeater Lake , Moreton Isl., 27.096°S, 153.434°E, leg. T.J. Page & J.H. Fawcett, 15.iv.2003 ( AM P107225 ); 6 ovigerous female paratypes (pocl 2.8–3.5 mm), same data as holotype ( AM P107226 ); 4 ovigerous female paratypes (pocl 2.5–3.4 mm), same data as holotype ( AM P107227 ) .

Other material examined. Male (pocl 3.0 mm; illustrated), Brown Lake, Moreton Isl., 27.493°S, 153.430°E, leg. T.J. Page, R.K. Stuart & A. Hinde, 16.iii.2003 ( AM P107228 ) .

Diagnosis. As the species is morphologically very similar to C. sobrina , only a diagnosis is provided.

Rostrum long, slightly or more prominent, pointed downwards; failing to reach or overreaching distal margin of scaphocerite ( Fig. 5A ); upper margin bearing 17–24 sutured, equidistant teeth, with additionally 2–4 placed behind orbit; ventral margin with 4–6 teeth. Lower orbital angle prominent, weakly triangular ( Fig. 5A ). Stylocerite of antennular peduncle reaching to distomedial margin of basal segment. Preanal carina with well-developed upright tooth ( Fig. 5K ). Telson bearing 4 pairs of dorsolateral spinules; distal margin with medial tooth and 4 pairs of setulose, spiniform setae ( Fig. 5I–H ). Flexor margin of P3 dactylus with 9–11 (counting unguis) spiniform setae ( Fig 5E ). Dactylus of P5 with 29–33 (counting unguis) spinules on flexor margin ( Fig. 5F ). Male first pleopod ( Fig. 5G ) with endopod conical in overall shape. Appendix masculina ( Fig. 5D ) of second pleopod with series of long, spinulose setae; appendix interna shorter, about 0.75 of appendix masculina length, distally furnished with numerous cincinnuli. Uropodal diaeresis with 11–13 regularly spaced, short spiniform setae ( Fig. 5L ). Females with 9– 16 eggs, size of eggs 0.6–0.7 × 0.9–1.2.

Etymology. Named after Tim Page, prolific collector and sequencer of Australian Caridina , as well as an allround nice guy.

Distribution. Currently only known with certainty from Moreton Island (Blue Lagoon, Cravens Creek, Eagers Creek, Honeyeater Lake, Lake Jabiru, Spitfire Creek) and the western side of North Stradbroke Island (Aranarawai Creek, Brown Lake, Capembah Creek, Little Canalpin Creek) (see Page & Hughes 2007a: fig. 1).

Genbank COI haplotype accession number. AY795014 (AM P107225).

Remarks. The above diagnosis allows for the morphological separation of C. pagei sp. nov. from C. sobrina . Although these differences are slight and partially overlapping, the COI divergence of 9.6% (± 0.1) supports species level status.

Figures

FIGURE 5. Caridina pagei sp. nov. Holotype, female (AM P107225): A, carapace and cephalic appendages; B, antennule. Male (AM P107228): C, carapace and cephalic appendages; D, appendix masculina and appendix interna; E, dactylus of third pereiopod; F, dactylus of fifth pereiopod; G, endopod of first pleopod. Female ovigerous (AM P107226): H, telson; I, distal part of telson; K, preanal carina; L, diaeresis. Scale bars: 1 mm (A–C, H, K); 0.25 mm (D–G, I, L).