Caridina buehleri Roux, 1934

Figs 2W, 12, 26A

Caridina buehleri Roux, 1934: 219, figs 1–5 (type locality: Bimoun, New Ireland west coast, Papua New Guinea).

Caridina buehleri – de Mazancourt et al. 2019a: 166, 169–170.

Material examined

Holotype

PAPUA NEW GUINEA • ♀, cl 7 mm; New Ireland, Bimoun; F. Speiser, H. Hediger and A. Bühler leg.; NMB 822.

Other material

SOLOMON ISLANDS – Kolombangara Island • 1 ♀ ovig., cl 3.8 mm; Liva River; 08°03.863´S, 157°10.633´E; 11 Nov. 2015; P. Keith, C. Lord and G. Marquet leg.; MNHN-IU- 2015-18 • 1 ♀ ovig., cl 4.1 mm; Pipiro River; 07°53.083´S, 157°08.195´E; 13 Nov. 2015; P. Keith, C. Lord and G. Marquet leg.; DNA voucher: CA1520; MNHN-IU- 2015-20 • 1 ♀ ovig., cl 4.3 mm; Vanga 2 River; 07°54.825´S, 156°57.762´E; 18 Nov. 2015; P. Keith, C. Lord and G. Marquet leg.; MNHN-IU- 2015–22 • 1 ♀ ovig., cl 2.8 mm; same collection data as for preceding; MNHN-IU-2016-5725 • 1 ♀ ovig., cl 4.5 mm; Vanga 1 River; 07°55.088´S, 156°57.624´E; 18 Nov. 2015; P. Keith, C. Lord and G. Marquet leg.; MNHN-IU- 2016-5726 • 1 ♀ ovig., cl 4.1 mm; Liva River; 08°03.863´S, 157°10.633´E; 11 Nov. 2015; P. Keith, C. Lord and G. Marquet leg.; MNHN-IU- 2016-28 • 1 ♀ ovig., cl 3.9 mm; Vagé River; 08°5.112´S, 156°59.867´E; 10 Nov. 2015; P. Keith, C. Lord and G. Marquet leg.; MNHN-IU-2016-5732 . – Vella Lavella Island • 1 ♀ ovig., cl 3.2 mm; Vala Kadju River; 07°49.860´S, 156°42.644´E; 17 m a.s.l.; 28 Oct. 2016; P. Keith and C. Lord leg.; MNHN-IU- 2018-2845 • 1 ♀ ovig., cl 3.7 mm; Wariassi River; 29 Oct. 2016; P. Keith and C. Lord leg.; DNA voucher: CA1997; MNHN-IU- 2018-2846 .

PAPUA NEW GUINEA – New Britain • 1 ♀ ovig., cl 3.5 mm; Vaavu River; 05°22.584´S, 50°03.724´E; 30 Oct. 2018; R. Causse, P. Keith and C. Lord leg.; MNHN-IU- 2018-2847 • 1 ♀ ovig., cl 4.0 mm; same collection data as for preceding; MNHN-IU- 2018-2848 • 1 ♀ ovig., cl 4.2mm; Walindi River; 05°21.187´S, 50°02.693´E; 30 Oct. 2018; R. Causse, P. Keith and C. Lord leg.; DNA voucher: CA2252; MNHN-IU- 2018-2849 .

VANUATU • 1 ♀ ovig., cl 6.0 mm; Malekula Island, Brenwe River; 16°07.593´S, 167°16.779´E; 54 m a.s.l.; 20 Nov. 2008; P. Feutry, P. Keith, C. Lord and L. Taillebois leg.; DNA voucher: CA1014; MNHN-IU- 2015-23 .

Description

CEPHALOTHORAX. Antennal spine below suborbital angle. Pterygostomian margin sub rectangular. Rostrum (Fig. 12l): 0.4–0.7 of cl, reaching to distal end of antennular peduncle, armed with 13–16 teeth on dorsal margin, 2–5 of them situated on carapace behind orbital margin, ventral margin with 2–5 teeth. Eyes well developed, anterior end reaching to 0.66 length of basal segment of antennular peduncle. Antennular peduncle 0.50–0.55 (♀) times as long as carapace. Anterolateral angle reaching 0.30 length of second segment, basal segment of antennular peduncle longer than sum of second and third segment lengths, second segment distinctly longer than third segment. Stylocerite sharp, long, reaching to about half of second segment of antennular peduncle.

PEREIOPODS. Epipods on first four pereiopods. P1 (Fig. 12a): chela about 2.2–2.3 times as long as wide, movable finger 2.1–2.8 times as long as wide, 0.5–0.8 times length of palm; carpus 1.5–1.7 times as long as wide. P2 (Fig. 12b) more slender and longer than first pereiopod, with chela 2.6–3.1 times as long as wide: movable finger 4.0–4.5 times as long as wide, 1.3–1.7 times length of palm; carpus slender, 5.5–6.2 times as long as wide. P3 (Fig. 12c): dactylus (Fig. 12e) 3.0–3.5 times as long as wide (terminal spiniform seta included) with 5–6 spiniform setae on flexor margin in addition to terminal one; propodus 9.0–10.2 times as long as wide, 3.6–4.4 times as long as dactylus. P5 (Fig. 12d): dactylus (Fig. 12f) 3.7–4.7 times as long as wide, with 27–33 spiniform setae on flexor margin; propodus 11.5–14.4 times as long as wide, 3.8–4.1 times as long as dactylus.

ABDOMEN. Third abdominal somite with moderately convex dorsal profile. Sixth abdominal somite 0.47 times as long as carapace, 1.6 times as long as fifth somite, shorter than telson.

TELSON (Fig. 12i). 2.4 times as long as wide, with four pairs of dorsal spinules and one pair of dorsolateral spinules; posterior margin with median process, broadly convex with 7–9 plumose intermediate setae much longer than lateral ones.

MALE PLEOPODS. No males.

PRE- ANAL CARINA (Fig. 12j). High, unarmed.

UROPODAL DIAERESIS (Fig. 12h). With 17–21 spinules.

EGGS (Fig. 12k). Size: 0.20–0.27 × 0.33–0.43.

Habitat

This species lives in a typical brackish water environment (brackishwater pools or lower part of rivers, near the estuary). The species is rarely found over the superior limit of the tide-influenced zone, and was not found in the true freshwater zone.

Colour pattern (Fig. 26A)

Body usually dark red to black, with a lighter dorsal band from the rostrum to the telson and sometimes white stripes on each abdominal somite.

Distribution

This species occurs in Solomon Islands (Kolombangara, Vella Lavella), in the Vanuatu archipelago (Malekula and Santo islands) and in Papua New Guinea (New Britain).

Remarks

de Mazancourt et al. (2017a) redescribed C. buehleri in detail, but their description actually represented two species: C. buelheri described by Roux sensu stricto and another species, C. gueryi, described by Marquet et al. 2009 and redescribed below. Indeed, our specimens fit well with the holotype from New Ireland (PNG) by its P5 dactylus 3.7–4.7 as long as wide (vs 3.6) with 27–33 spiniform setae on flexor margin (vs 30), propodus 11.5–14.4 times as long as wide (vs 9.4), 3.8–4.1 times as long as dactylus (vs 3.8).