Caridina meridionalis J. Roux 1926
Creators: name: Richard, Jasmine
name: Clark, Paul F.
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Atyidae
Caridina
Caridina meridionalis

description: Caridina meridionalis J. Roux, 1926
(Figs. 11, 12)
Caridina nilotica var. meridionalis J. Roux 1926a: 207 (partim).
Nec Caridina nilotica var. meridionalis. Reik 1953: 117, fig. 6 (= Caridina brachydactyla).
Material examined. Types: Cotype. New Caledonia. Pemboa Gegend, coll. F. Sarasin & J. Roux, 1 Mai 11, NMB reg. 4.VIII.b, Lectotype. 1♂, Paralectotypes. 3♂, 2♀ ovig., 5♀ are designated by the present study.
Description. Adult size: 20–30 mm Carapace length 4–4.3 mm.
Rostrum (Fig. 11 a–c): Equal to antennular peduncle or slightly longer. 0.75–0.9×long as carapace 3.0–4.0 mm in length. 19–27 teeth present on the dorsal margin up to the tip, the proximal teeth are compact and the distal 1–5 teeth spaced. 2 post orbital teeth present, tip pointed or bifid, ♀ ovig. (2)23/10, ♂ (2)22/6, ♂ (2)27/7, ♀ (2)19/8, ♂ (2)22/8, one cephalothorax separated specimen (2)19/7; one separated rostrum had 4 teeth) 4–10 teeth on the ventral margin up to the tip or with a short unarmed end distally. Formula 19–27/4–10.
Antennular peduncle (Fig. 11 a–c): 0.65–0.75×carapace. Stylocerite 0.6–0.7×length of basal segment. Anterolateral teeth of basal segment 0.15–0.25×second segment. 9–15 segments bearing aesthetascs.
First pereiopod (Fig. 12 a): Dactylus 1.0–1.3×palm of propodus. Chela 1.9–2.0×long as broad. Carpus 1.9–2.2×long as broad, with the anterior excavation.
Second pereiopod (Fig. 12 b): Dactylus 1.5–1.7×long as palm of propodus. Chela 2.5–2.8×long as broad. Carpus 4.5–5.0×long as broad, a shallow anterior excavation present.
Third pereiopod (Fig. 12 c, d): dactylus 2.4–3×long as broad. 6–9 spines on dactylus (including terminal spines). Propodus 5.0–5.5×long as dactylus and 9–10×long as broad with 9–12 spines arranged along inner margin. Carpus 0.60–0.65×long as propodus, with 1 large spine and 3–4 small spines on inner margin. Merus 1.7–2.0×carpus length. Merus with 3 large spines along posterior margin. Ischium with one spine.
Fifth pereiopod (Fig. 12 e, f): Dactylus 3.75–4.2×long as broad with 45–55 spines arranged in comb-like fashion on inner margin. Propodus 12–15×long as broad and 4.5–5.0×long as dactylus with 10–15 spines arranged along posterior margin. Carpus 0.5–0.6×propodus length and with one large spine and 3–4 minute spines along inner margin. Merus 1.5–1.7×carpus length, with 2 large spines along posterior margin. Ischium with a spine.
Setobranch: With two setae on all pereiopods.
First male pleopod (Fig. 12 g, h): Endopod 0.45–0.55×exopod length; appendix interna present.
First female pleopod: Endopod 0.5–0.6×long as exopod.
Eggs (Fig. 12 i): ca. 300 eggs of 0.6–0.65× 0.35–0.39 mm size.
Second male pleopod (Fig. 12 j–k): Appendix masculina 1.5–2.0×appendix interna 0.4×endopod.
6th abdominal somite: 0.5–0.6×long as carapace.
Telson (Fig. 12 l–n): 1.0–1.1×long as 6th abdominal somite. 3–5 pairs of dorsal spines (including subterminal spines). Posterior margin triangular converging to median pointed process with 1 pair of long lateral spines and two pairs of intermediate spines that are slightly shorter than the lateral spines.
Uropod (Fig. 12 o): 9–12 diaeresis spinules.
Preanal carina: unarmed.
Distribution. New Caledonia.
Type locality. Pemboa Gegend, New Caledonia.
Remarks. Jean Roux depicts C. n. meridionalis from New Caledonia (Roux 1926a) and Queensland, Australia (Roux 1926b). In a footnote Roux (1926b: 237) states “Since completion of this paper (Roux 1926b Australian Atyidae) the author (J. Roux) has finished and published a work on Decapoda of New Caledonia ”. Therefore the New Caledonia description of C. n. meridionalis is considered to take presidence over that from Australia.
Caridina n. meridionalis was described by Roux (1926a) from 7 localities in New Caledonia. This type series was found to comprise C. n. meridionalis, C. peninsularis and three undescribed species. The first place mentioned by Roux (1926a), Pemboa Gegend, New Caledonia, is here considered as the type locality and these specimens are re-described by the present study as C. n. meridionalis. A male from Pemboa Gegend has been selected as the Lectotype and the remaining specimens from this locality are considered Paralectotypes. Furthermore, C. n. meridionalis is given specific status and the description of this species from Queensland, Australia is considered here as C. brachydactyla.
Caridina meridionalis is distinct with a rostrum that reaches the antennular peduncle or slightly longer with 19–27 teeth on dorsal margin of which the proximal teeth are compact and the distal 1–5 teeth spaced, 2 post orbital teeth present, 4–10 teeth on the ventral margin up to the tip or with a short unarmed end, ca. 300 eggs of 0.6–0.65× 0.35–0.39 mm size, the posterior margin of the telson triangular with long lateral spines and 2 pairs of intermediate spines, slightly shorter than the lateral spines.
Caridina meridionalis differs from C. nilotica (see Richard & Clark 2005) by the morphology of rostrum, telson and egg number and size. In C. meridionalis the rostrum is straight (vs. upturned in C. nilotica); the rostrum is shorter than the antennal scale (vs. longer than the antennal scale, rarely equal to scale in C. nilotica); with 19–27 teeth always up to the tip on dorsal margin, the distal 1–5 teeth spaced (vs. with teeth on proximal dorsal margin always leaving the distal margin unarmed in C. nilotica); mostly with pointed tip (vs. tip of the rostrum is usually bifid in C. nilotica); fewer number of teeth on the ventral margin, 4–10 (vs. more teeth on ventral margin, 10–28 in C. nilotica); the lateral spines and intermediate spines at the posterior margin of the telson are longer (vs. posterior margin of the telson is flat and bears 1–3 pairs of short intermediate spines in C. nilotica); ca. 300 eggs of 0.6–0.65× 0.35–0.39 mm size (vs. 85– 140 eggs of 0.5–0.85× 0.35–0.55 mm size present in C. nilotica).
Caridina meridionalis appears to be closer to C. simoni in the morphology of the rostrum. However, examination reveals differences between the two species. In C. meridionalis the rostrum is shorter than the antennal scale (vs. rostrum reaches the end of the antennal scale or slightly longer in C. simoni); pointed or bifid tip (vs. tip pointed in C. simoni); 19–27 teeth on the dorsal margin of which the proximal being compact and distal 1–5 being spaced (vs. 15–25 teeth placed proximally leaving 0.25–0.4 of dorsal margin distally either unarmed or interrupted by 1–4 teeth in C. simoni); 2 post orbital teeth present (vs. 3–5 post orbital teeth present in C. simoni); 4–10 teeth placed mid-ventrally up to the tip or with a short anterior unarmed ventral margin (vs. 5–14 teeth on the ventral margin proximally leaving 0.25–0.35 of the ventral margin always unarmed in C. simoni); posterior margin of telson is narrow and triangular converging to median pointed process with 1 pair of long lateral spines and two pairs of intermediate spines that are slightly shorter than the lateral spines (vs. posterior margin of the telson is broad and rounded mostly without a median process, bearing 1 pair of long lateral spines and 3–4 pairs of sparsely plumose spines that are shorter than laterals or inner pair of spines of equal length to the lateral spines in C. simoni); ca. 300 eggs of 0.6–0.65× 0.35–0.39 mm size (vs. ca. 50– 160 eggs of 0.65–1.0× 0.45–0.6 mm size in C. simoni). These morphological differences indicate that C. meridionalis is distinct from C. simoni, and that the decision of Johnson (1963) to consider C. meridionalis as a junior synonym of C. simoni was incorrect.
description: Published as part of Richard, Jasmine & Clark, Paul F., 2014, Caridina simoni Bouvier, 1904 (Crustacea: Decapoda: Caridea: Atyoidea: Atyidae) and the synonymy by Johnson, 1963, pp. 301-338 in Zootaxa 3841 (3) on pages 321-324, DOI: 10.11646/zootaxa.3841.3.1, http://zenodo.org/record/228244