Caridina elisabethae, Karge & Rintelen & Klotz, 2010

Karge, Andreas, Rintelen, Kristina Von & Klotz, Werner, 2010, On two small collections of freshwater shrimps (Decapoda: Atyidae: Caridina) from Papua New Guinea, with descriptions of two new species *, Zootaxa 2372 (1), pp. 138-150 : 142-145

publication ID	https://doi.org/ 10.11646/zootaxa.2372.1.14
persistent identifier	https://treatment.plazi.org/id/03C687A6-EA06-FFB7-FF01-0FE24282FDA4
treatment provided by	Felipe
scientific name	Caridina elisabethae
status	sp. nov.

Treatment

Caridina elisabethae View in CoL sp. nov.

( Figs. 3–4 View FIGURE 3 View FIGURE 4 )

Material examined. Holotype male, cl 4.00 mm ( ZMB 29469), Papua New Guinea, Morobe, Herzog Mts., Bundun , 700–800 m, 06°51.598’S, 146°37.07’E, leg. M. Balke & K. Sagata, 2.IV.2006 GoogleMaps . Paratypes: 1 female, cl 4.70 mm ( ZMB 29470), same data as holotype GoogleMaps ; 1 male, cl 3.50 mm ( ZCPNG), same data as holotype GoogleMaps .

Diagnosis: Rostrum ( Fig. 3A View FIGURE 3 ) slightly sigmoid, reaching near to or slightly beyond end of antennular peduncle, with 1 small movable tooth near tip, 5 or 6 ventral teeth; rostral formula: 2-3 + 13–17 + 1 / 5–6. Preanal carina ( Fig. 4I View FIGURE 4 ) rounded, without a tooth or spine. Chela of first pereiopod 2.05–2.27 as long as wide, dactylus 0.96–1.28 times as long as palm; carpus 1.80–2.34 times as long as wide. Chela of second pereiopod 2.36–2.82 times as long as wide, dactylus 1.35–1.82 times as long as palm; carpus 3.75–5.00 times as long as wide. Endopod of male first pleopod ( Fig. 4K View FIGURE 4 ) elongated triangular, 2 times as long as proximal width, with a vestige or without appendix interna.

Description. Rostrum ( Fig. 3A View FIGURE 3 ) slightly sigmoid, reaching near to or slightly beyond end of antennular peduncle, 0.75–0.87 times as long as carapace, armed dorsally with 15–19 teeth including 2 or 3 on carapace posterior to orbital margin, terminal 40–50% of dorsal margin unarmed, with 1 small movable tooth near tip, 5 or 6 ventral teeth; rostral formula: 2–3 + 13–17 + 1 / 5–6.

Inferior orbital angle fused with antennal spine. Pterygostomial angle subrectangular. Antennular peduncle 0.62–0.82 times as long as carapace, second segment 1.31–1.55 times length of third segment, third segment 0.38–0.41 times as length of basal segment. Stylocerite 0.77–0.94 times as long as basal segment of antennular peduncle. Scaphocerite ( Fig. 3B View FIGURE 3 ) 3.13–3.51 times as long as wide.

Sixth abdominal somite 0.53–0.60 times length of carapace, 2 times as long as fifth somite, slightly shorter than telson. Telson ( Figs. 4G–H View FIGURE 4 ) 2.84 times as long as proximally wide, distal margin broadly rounded, with indistinct or without median projection, with 3 or 4 pairs of dorsal and 1 pair of dorsolateral spinules, distal end with 8 or 9 spines, lateral pair longer than intermediate spines. Preanal carina ( Fig. 3I View FIGURE 3 ) rounded, without a tooth or spine. Uropodal diaeresis ( Fig. 4J View FIGURE 4 ) with 11–13 movable spinules.

Incisor process of mandible ( Fig. 3C View FIGURE 3 ) ending in irregular teeth, molar process truncated. Lower lacinia of maxillula ( Fig. 3D View FIGURE 3 ) broadly rounded, upper lacinia elongate, with numerous distinct teeth on inner margin, palp slender with few simple setae at tip. Upper endites of maxilla ( Fig. 3E View FIGURE 3 ) subdivided, palp short, scaphognathite tapering posteriorly, fringed with long, curved setae at posterior margin. Palp of first maxilliped ( Fig. 3F View FIGURE 3 ) ending in a distinct finger-like projection. Podobranch on second maxilliped ( Fig. 3G View FIGURE 3 ) well developed. Third maxilliped ( Fig. 3H View FIGURE 3 ) with 2 arthrobranchs, ultimate segment slightly shorter than penultimate segment. Pleurobranchs present on all pereiopods. First pereiopod with 1 arthrobranch. Well developed epipods present on third maxilliped and first 4 pereiopods.

Chela and carpus of first pereiopod distinctly stouter and broader than chela and carpus of second pereiopod ( Figs. 3A–B View FIGURE 3 ); chela of first pereiopod 2.05–2.27 as long as wide, 1.26–1.50 times length of carpus; tips of fingers rounded, without hooks; dactylus 0.96–1.28 times as long as palm; carpus 1.80–2.34 times as long as wide, 0.92–1.00 times length of merus. Chela of second pereiopod 2.36–2.82 times as long as wide, 0.82–1.00 times length of carpus; tips of fingers rounded, without hooks, dactylus 1.35–1.82 times as long as palm; carpus 3.75–5.0 times as long as wide, as long as or slightly longer than merus. Third pereiopod ( Figs. 4C, E View FIGURE 4 ) slender, dactylus 3.0–3.5 times as long as wide (terminal spine included, without spines on flexor margin), terminating in one large claw with 5 or 6 accessory spines on flexor margin; propodus 9.57–10.29 times as long as wide, 3.53–4.28 times as long as dactylus; carpus 4.60–4.95 times as long as wide, 0.65–0.69 times as long as propodus, 0.52–0.59 times as long as merus; merus 6.26–6.32 times as long as wide, 1.68– 1.91 times as long as carpus, bearing 1–2 movable spines on posterior margin of outer surface. Fifth pereiopod slender ( Figs. 4D, F View FIGURE 4 ), dactylus 4.55–4.67 times as long as wide (terminal spine included, without spines on flexor margin), terminating in 1 large claw with 37–42 spinules on flexor margin; propodus 10.56–12.57 times as long as wide, 3.39–3.52 times length of dactylus, carpus 5.22 times as long as wide, 0.53–0.54 times as long as propodus, 0.64 times as long as merus; merus 6.15–7.30 times as long as wide, 1.55–1.57 times length of carpus, bearing 1 or 2 strong, movable spines on posterior margin of outer surface.

Endopod of male first pleopod ( Fig. 4K View FIGURE 4 ) elongated triangular, 2 times as long as proximal width, 0.3 times as long as exopod, with a vestige or without appendix interna. Appendix masculina on male second pleopod ( Fig. 4L View FIGURE 4 ) slender, rod-like, with long spines on inner and distal margin, appendix interna reaching to about two-thirds of appendix masculina.

Reproductive biology unknown, no ovigerous females were present in the material examined.

Etymology. Caridina elisabethae is dedicated to Elisabeth Hintelmann from Munich for her great support of systematic research.

Remarks. Caridina elisabethae shares some characters with C. demani , but can be distinguished from this species by the presence of a small tooth near the distal end of the rostrum and more slender first and second chelipeds (chela 2.05–2.27 and 2.36–2.82 times as long as wide vs. 1.81–1.96 and 2.08–2.29 times in C. demani , carpus 1.80–2.34 and 3.75–5.0 times as long as wide vs. 1.45–1.54 and 3.37–3.91 times in C. demani ). The endopod of the male first pleopod is also relatively more slender in C. elisabethae (two times as long as proximal width vs. 1.4 times in C. demani ). From C. cognata , C. elisabethae differs by the shape and armature of the rostrum and the slightly stouter carpus on second pereiopod (3.75–5.0 times as long as wide vs. 4.00–5.18 times in C. cognata ).

In possessing a small tooth near the tip of the rostrum, C. elisabethae also resembles C. nilotica . The shape of this tooth, however, is somewhat different from the “true” subapical tooth found in C. nilotica and members of the C. nilotica species group (De Man, 1908).

From the single specimen of C. nilotica "forma typica" reported from Papua New Guinea by J. Roux (1917), C. elisabethae can easily be differentiated by a shorter rostrum with few ventral teeth (5 or 6 vs. 19 in C. nilotica “forma typica”), shorter dactyli on the first pair of chelipeds (0.96-1.28 times as long as palm vs. 1.8 times as long in C. nilotica “forma typica”), and stouter carpi on the second chelipeds (3.75–5.0 times as long as wide vs. 6 times as long as wide in C. nilotica “forma typica”). According to Richard & Clark (2005), C. nilotica is restricted to the River Nile catchment area in Africa, and the presence of C. nilotica in the Indo- Pacific area should be re-evaluated. However, from C. nilotica , C. elisabethae differs in the same characters as from the Papuan specimen viz. a shorter rostrum (0.75-0.87 times as long as carapace vs. 1.0–1.13 times as long in C. nilotica ) with less numerous ventral teeth (5 or 6 vs. 10–28 in C. nilotica ), shorter dactyli on the first pair of chelipeds (0.96-1.28 times as long as palm vs. 1.2–1.9 times as long in C. nilotica ), furthermore, in the armature of the dactyli on the third pereiopod (with 5–6 spinules on flexor margin vs. 6–10 in C. nilotica ) and a different shape and armature of the distal margin of the telson (broadly rounded with 3 or 4 pairs of distal spines vs. convex with 1–3 pairs of distal spines).