Caridina lingkonae Woltereck, 1937a

Rintelen, Kristina von & Cai, Yixiong, 2009, Radiation Of Endemic Species Flocks In Ancient Lakes: Systematic Revision Of The Freshwater Shrimp Caridina H. Milne Edwards, 1837 (Crustacea: Decapoda: Atyidae) From The Ancient Lakes Of Sulawesi, Indonesia, With The Description Of Eight New Species, Raffles Bulletin of Zoology 57 (2), pp. 343-452 : 373-377

Caridina lingkonae Woltereck, 1937a

( Figs. 15-17 , Table 7)

Caridina Lingkonae Woltereck, 1937a: 218 , fig. I.1, pls. 3,6 (type locality: Lake Towuti at Loéha Island and at Lingkona [Lengkona]).

Caridina lingkonae – Woltereck, 1937b: 299, fig. 6; Chace, 1997: 13; von Rintelen et al., 2008: 2244, Table 1.

Cardina lingkonae – Brooks, 1950: 168 (erroneous spelling).

Caridina linkonae – Fernandez-Leborans et al., 2006b: 1985, Table I (erroneous spelling).

Material examined. – Neotype: ovigerous female (cl. 4.1 mm)( MZB Cru. 1554), Lake Towuti , west shore, at entrance to outlet bay, Cape Larona, 02°48.43'S, 121°24.75'E, loc. 73-03, pelagic, coll. K. & T. von Rintelen, 27 Sep.2003.

Others from Lake Towuti: 184 ex. ( MZB Cru 1763, n=149; ZMB 29076, n=35, some SEM material), west shore, at entrance to outlet bay, Cape Larona, 02°48.43'S, 121°24.75'E, loc. 73-03, pelagic, coll. K . & T. von Rintelen , 27 Sep.2003 ; 18 ex. ( MZB Cru 1764, n=9; ZMB 29235, n=9), southwest shore, west of Cape Tetetu, 02°54.13'S, 121°23.78'E, loc. 76-03, pelagic, coll. K . & T. von Rintelen , 28 Sep.2003 ; 1 ex. ( ZMB 29239), east shore, south of Cape Tomeraka , 02°44.47'S, 121°37.53'E, loc. 70-03, on rocks, coll. K . & T. von Rintelen , 9 Oct.2003 ; 1 ex. ( ZMB 29282), west shore, Cape Larona , 02°48.526'S, 121°25.044'E, loc. 120-04, boulders in deeper water, coll. K . & T. von Rintelen , 29 Jul.2004 ; 3 ex. ( ZMB 29283), west shore, west of Cape Timbalo , 02°42.631'S, 121°26.389'E, loc. 145-04, on mixed substrate, coll. K . & T. von Rintelen , 26 Jul.2004 ; 1 ex. ( ZMB 29287), outlet bay, at Cape Kombe , 02°48.083'S, 121°23.049'E, loc. 118-04, on boulders in deeper water, coll. K . & T. von Rintelen , 29 Jul.2004 ; 15 ex. ( MZB Cru 1765, n=7; ZMB 29302, n=8), northeast shore, at Lengkona, 02°40.483'S, 121°41.382'E, loc. 116-04, on mixed substrate, coll. K . & T. von Rintelen , 28 Jul.2004 ; 3 ex. ( ZMB 29304), Loeha Island , west shore, 02°45.5'S, 121°31.06'E, loc. 951-03, on rocks, coll. K . & T. von Rintelen , 4 Oct.2003 ; 1 ex. ( ZMB 29316), northeast shore, at Cape Noote , 02°39.751'S, 121°39.195'E, loc. 117-04, pelagic, coll. K . & T. von Rintelen , 28 Jul.2004 ; 3 ex. ( MZB Cru 1766), west shore, outlet bay, 02°46.277'S, 121°21.83'E, loc. 02-05, on sponge, coll. K . & T. von Rintelen , 3 Jan.2005 ; 7 ex. ( MZB Cru 1767), east shore, off Beau village, 02°48.99'S, 121°33.64'E, loc. 71-03, on Ottelia , coll. K . & T. von Rintelen , 27 Sep.2003 .

Others from Lake Mahalona: 1 ex. ( ZMB 29208), east shore, at mouth of Petea River, 02°34.54'S, 121°30.48'E, loc. 55-03, on leaf litter, coll. K. & T. von Rintelen, 23 Sep.2003 .

Description. – Carapace length 2.3-4.5 mm (n=46). Rostrum ( Fig. 16 A-B; Table 7) long, reaching beyond end of scaphocerite, proximal part typically triangular, 1.0-1.6 times as long as carapace (n=46), armed dorsally with 17-29 teeth (including 3-5 teeth posterior to orbital margin), anteriorly less densely spaced, armed ventrally with 7-18 teeth. Antennal spine situated below inferior orbital angle. Pterygostomial angle broadly rounded. Eyes well developed, anterior end 0.6-0.7 times length of basal segment of antennular peduncle (n=5). Antennular peduncle 0.9-1.2 times as long as carapace (n=5), second segment 1.7-2.0 times length of third segment, third segment 0.3-0.4 times length of basal segment. Stylocerite reaching 0.8-0.9 times length of basal segment of antennular peduncle (n=5). Scaphocerite ( Fig. 16F ) 4.1-5.3 times as long as wide (n=5).

Sixth abdominal somite 0.7-0.9 times length of carapace (n=46), 1.6-1.9 times as long as fifth somite (n=20), 1.0- 1.3 times length of telson (n=26). Telson ( Fig. 16D,K ) 3.4-3.6 times as long as wide (n=5), distal margin rounded, without projection, with 3-4 pairs of spinules and 1 pair of dorsolateral spinules; distal end with 4 pairs of spines, lateral pair distinctly longer than intermediate pairs, median pair shortest. Preanal carina ( Fig. 16E ) with a spine. Uropodal diaeresis ( Fig. 16C ) with 9-11 movable spinules (n=5).

5 pairs of pleurobranchs well developed; 3 pairs of arthrobranchs, 2 on third maxillipeds, with second pair strongly reduced in size, 1 pair on first pereiopod; 1 pair of podobranchs on second maxilliped reduced strongly to a laminate form. Epipod reduced or absent from first pereiopod. Incisor process of mandible ( Fig. 17A ) ending in a row of small teeth, molar process truncated. Lower lacinia of maxillula ( Fig. 17B ) broadly rounded, upper lacinia elongate, with numerous distinct teeth on inner margin, palp slender. Upper endites of maxilla ( Fig. 17C ) subdivided, palp short, scaphognathite tapering posteriorly with numerous long, curved setae at posterior end. Distal end of palp of first maxilliped ( Fig. 17F ) triangular, with a finger-like projection; flagellum of the exopod very short, endopod high, distinctly exceed the flagellum of exopod in length. Second maxilliped ( Fig. 17E ) typical. Third maxilliped ( Fig. 17D ) with ultimate segment distinctly shorter than penultimate segment.

First and second pereiopod very slender, chela and carpus of first pereiopod distinctly stouter and broader than chela and carpus of second pereiopod ( Fig. 16 N-P); chela of first pereiopod 3.0-4.1 times as long as wide (n=20), 0.9-1.1 times length of carpus (n=46); tips of fingers rounded, without hooks; dactylus 1.7-1.9 times as long as palm (n=5); carpus 4.4-5.0 times as long as wide (n=20), 1.3-1.4 times length of merus (n=5). Chela of second pereiopod 4.2-5.6 times as long as wide (n=20), 0.6-0.8 times length of carpus (n=46); tips of fingers rounded, without hooks, dactylus 1.4-1.6 times as long as palm (n=5); carpus 7.9-10.7 times as long as wide (n=20), 1.6-1.7 times as long as merus (n=5).

Third pereiopod ( Fig. 16G,I ) slender, dactylus 4.3-5.5 times as long as wide (terminal spine included, without spines of flexor margin; n=5), terminating in one large claw with 1-3 accessory spines on flexor margin; propodus 13.2-17.0 times as long as wide, 3.9-4.9 times as long as dactylus; cl (mm) 2.3-4.5 3.5 ± 0.6 3.6 46 rl / cl 1.0-1.6 1.3 ± 0.1 1.2 46 n dorsal rostral teeth 17-29 22 ± 3 22 46 n ventral rostral teeth 7-18 12 ± 2 12 46 abds6 / cl 0.7-0.9 0.8 ± 0.1 0.8 46 abds6 / abds5 1.6-1.9 1.8 ± 0.1 1.8 20 abds6 / h tel [phone] h tel / w tel 3.4-3.6 3.5 ± 0.1 3.5 5 n spines uropodal diaeresis 9-11 10 ± 1 10 5 h ch1 / w ch1 3.0-4.1 3.5 ± 0.3 3.5 20 h ch1 / h ca1 0.9-1.1 1.0 ± 0.1 1.0 46 h ca1 / w ca1 4.4-5.0 4.7-0.2 4.7 20 h ch2 / w ch2 4.2-5.6 4.8 ± 0.3 4.8 20 h ch2 / h ca2 0.6-0.8 0.7 ± 0.0 0.7 46 h ca2 / w ca2 7.9-10.7 9.6 ± 0.7 9.6 20 n spines p3 1-3 2 ± 1 1 5 n spines p5 17-42 33 ±10 36 5

carpus 5.3-5.9 times as long as wide, 0.5 times as long as propodus, 0.4-0.5 times as long as merus; merus 10.5-12.2 times as long as wide, bearing 3-4 strong, movable spines on posterior margin of outer surface.

Fifth pereiopod slender ( Fig. 16H,J ), dactylus 3.5-5.6 times as long as wide (terminal spine included, without spines of flexor margin; n=5), terminating in one large claw with 17- 42 accessory spines on flexor margin; propodus 14.0-19.3 times as long as wide, 4.3-5.5 times as long as dactylus; carpus 5.3-6.1 times as long as wide, 0.4-0.6 times as long as propodus, 0.5-0.6 times as long as merus; merus 10.0-12.4 times as long as wide, bearing 2-5 strong, movable spines on posterior margin of outer surface.

Endopod of male first pleopod ( Fig. 16L ) elongated triangular, 2.0-2.5 times as long as proximally wide (n=5), without appendix interna. Appendix interna of male second pleopod ( Fig. 16M ) 0.8-0.9 times length of appendix masculina (n=5).

Ovigerous females with 30- 32 eggs (n= 3 females); egg size 0.7-1.0 x 0.4-0.6 mm (n=90, eggs with and without eyes).

Distribution. – Endemic to the Malili lakes, widely distributed in Lake Towuti, a single specimen was caught in Lake Mahalona ( Fig. 15A ).

Biology and ecology. – Caridina lingkonae was already mentioned as littoral and pelagic by Woltereck (1937a: 229) and Brooks (1950: 168). The majority of the specimens caught between 2003 and 2004 were found in huge pelagic swarms similarly to those of C. ensifera from Lake Poso. Although it was likewise found sporadically on other substrates (e.g. rocks or leaf litter), C. lingkonae is here regarded as a typical pelagic species. In comparison, C. lanceolata was also found in occasionally pelagic swarms, but the majority of specimens of that species occurred in the littoral on various kind of substrate. When disturbed, it tries to escape in all directions.

Colour pattern. – C. lingkonae has a translucent reddish body colouration throughout, similarly to C. lanceolata , but more pronounced ( Fig. 15B ). Ovigerous females bear green eggs.

Taxonomic remarks. – C. lingkonae might be confused with C. lanceolata in the field, especially when occurring as a pelagic swarm, but a generally stouter body and the typical triangular shape of the rostrum (vs. not triangular, but longer and more slender in C. lanceolata ) are characteristic for this species. C. lingkonae can further be distinguished by the dorsal denticulation of the rostrum (17-29 continuous teeth vs. 8-19 teeth including an unarmed gap in C. lanceolata ) and a shorter sixth abdominal segment compared to the carapace length (0.7-0.9, median 0.8 vs. 0.8-1.1, median 1.0 in C. lanceolata ). The typical triangular shape of the proximal part of the rostrum (best visible transilluminated), and its dense dorsal and ventral denticulation in C. lingkonae , has already been mentioned by Woltereck (1937a: 218,b: 299). A similarly triangular shape is pronounced in C. profundicola , but this species differs from C. lingkonae by a distinctly more slender and also longer rostrum compared to carapace length (1.4-2.8, median 1.9 vs. 1.0-1.6, median 1.2 in C. lingkonae ) and a higher number of ventral teeth (13-24, median 20 vs. 7-18, median 12 in C. lingkonae ). C. lingkonae has similarly slender pereiopods than C. profundicola and C. spinata that further distinguish C. lingkonae from all other species. Furthermore, C. lingkonae differs from C. spinata by the shape of the rostrum and less spines on the uropodal diaeresis; 9-11, median 10 vs. 12-16, median 14 in C. spinata ).

In the molecular phylogeny ( Figs. 63-64 ), C. lingkonae is genetically distinct from all ancient lake species.

Figures

Fig. 15. Caridina lingkonae from the Malili lake system. A. Distribution. B. Colour pattern of living animal (not to scale). Picture courtesy of Chris Lukhaup.

Fig. 16. Caridina lingkonae from the Malili lake system. A. Cephalothorax and cephalic appendages, female (ZMB 29076); B. Woltereck’s drawings of the rostrum, Lake Towuti (modified from 1937a); C. Uropodal diaeresis, female (ZMB 29076); D. Telson; E. Preanal carina, male (ZMB 29076), F. Scaphocerite; G. Third pereiopod, female (ZMB 29076); H. Fifth pereiopod; I. Dactylus of third pereiopod; J. Dactylus of fifth pereiopod; K. Distal end of telson; L. Endopod of male first pleopod (ZMB 29076); M. Appendix masculina of male second pleopod; N. SEM image of chela and carpus of first and second pereiopods; O. First pereiopod; P. Second pereiopod. Scale bars: A, F = 1.0 mm; D-E, G-H, L-P = 0.5 mm; C, I-K = 0.1 mm; B = no scale available.

Fig. 17. Caridina lingkonae from the Malili lake system. A. Mandible (ZMB 29076); B. Maxillula; C. Maxilla; D. third maxilliped; E. second maxilliped; F. first maxilliped. Scale bars: A-F = 1mm.

Fig. 63. Bayesian Inference phylogram (mtDNA, 16S and COI) of Caridina from the ancient lakes of Sulawesi (for other taxa compare von Rintelen et al., in review). Numbers on branches are, from top, Bayesian posterior probabilities, ML and MP bootstrap values. The scale bar indicates the number of substitutions per site. For each sequenced specimen museum accession numbers are provided. Locality abbreviations (compare Fig. 1): Lam (Lampesue River catchment), LT (Lake Lontoa), MHL (Lake Mahalona), MS (Lake Masapi), MT (Lake Matano), MTca (Lake Matano catchment), Pat (Patingko River), Pon (Ponsoa River), TW (Lake Towuti), TWca (Lake Towuti catchment), PS (Lake Poso), PSca (Lake Poso catchment), SSul (South Sulawesi), SESul (Southeast Sulawesi).

Fig. 64. Bayesian Inference phylogram (mtDNA, 16S and COI) showing taxa within the two Malili clades (for other taxa compare von Rintelen et al., 2009). For each sequenced specimen museum accession numbers are provided. Locality abbreviations (compare Fig. 1): Lam (Lampesue River catchment), LT (Lake Lontoa), MHL (Lake Mahalona), MS (Lake Masapi), MT (Lake Matano), MTca (Lake Matano catchment), Pat (Patingko River), Pon (Ponsoa River), TW (Lake Towuti), TWca (Lake Towuti catchment), SSul (South Sulawesi).