Caridina spinata 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 : 401-405

Caridina spinata Woltereck, 1937a

( Figs. 33–35 ; Table 13)

Caridina spinata Woltereck, 1937a: 221 , fig. I.3, pls. 3,6 (type locality: Lake Towuti, Lake Matanno [Matano]).

Caridina spinata – Woltereck, 1937b: 302, fig. 8; Chace, 1997: 20; von Rintelen et al., 2008: 2244, Table 1; Cai et al., 2009: 25, Fig. 6 (type locality of neotype: Lake Towuti, about 3 km south of Timampu, estuary of Sungei [River] Batuopa).

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

Not: Caridina spinata – von Rintelen et al., 2007b: 262, fig. 2b. Material examined. – Lake Towuti: 19 ex. ( MZB Cru 1555, n=10 and ZMB 29026, n=9, some SEM material), west shore, at entrance to outlet bay, Cape Larona, 02°48.43'S, 121°24.75'E, loc. 73-03, coll. K . & T. von Rintelen , 8 Oct.2003 ; 1 ex. ( ZMB 29056, n=1 and few juveniles, some SEM material), east shore, south of Cape Tomeraka , 02°44.47'S, 121°37.53'E, loc. 70-03, coll. K . & T. von Rintelen , 27 Sep.2003 ; 1 ex. ( ZMB 29057, n=1 and few juveniles), southwest shore, west of Cape Tetetu , 02°54.13'S, 121°23.78'E, loc. 76-03, coll. K . & T. von Rintelen , 28 Sep.2003 ; 1 ex. ( ZMB 29058, some SEM material), Loeha Island , north shore, 02°45.64'S, 121°34.32'E, loc. 97-03, coll. K . & T. von Rintelen , 4 Oct.2003; ( ZMB 29141, n=few juveniles) , south shore, approx. 2 km east of Cape Mea , 02°55.8'S, 121°26.92'E, loc. 74-03, coll. K . & T. von Rintelen , 28 Sep.2003; ( ZMB 29142, n=few juveniles) , north shore, bay east of Cape Bintu , 02°39.48'S, 121°33.25'E, loc. 68-03, coll. K . & T. von Rintelen , 26 Sep.2003 ; 1 ex. ( ZMB 29154), Larona River , close to outlet bay, 02°45.8'S, 121°20.8'E, loc. 51-03, coll. K . & T. von Rintelen , 28 Jul.2004 ; 2 ex. ( ZMB 29434), Loeha Island , north shore, 02°45.324'S, 121°32.019'E, loc. 226-05, coll. K . & T. von Rintelen , 23 Oct.2005 ; 6 ex. ( MZB Cru 1556), northeast shore, at Cape Noote, 02°39.751'S, 121°39.195'E, loc. 117-04, coll. cl (mm) 3.0-5.0 4.1 ± 0.6 4.2 17 rl / cl 0.9-1.7 1.3 ± 0.2 1.2 16 n dorsal rostra teeth 14-24 17 ± 3 17 16 n ventral rostral teeth 5-12 8 ± 2 9 16 abds6 / cl 0.5-0.7 0.6 ± 0.0 0.6 18 abds6 / abds5 1.5-1.9 1.7 ± 0.1 1.7 11 abds6 / h tel 0.8-1.0 0.9 ± 0.0 0.9 12 h tel / w tel 3.2-3.6 3.3 ± 0.1 3.3 6 n spines uropodal diaeresis 12-16 14 ± 1 14 6 h ch1 / w ch1 2.0-3.6 2.8 ± 0.6 3.0 13 h ch1 / h ca1 0.9-1.4 1.1 ± 0.2 1.0 18 h ca1 / w ca1 2.1-5.2 3.7 ± 1.3 4.5 12 h ch2 / w ch2 2.3-5.5 3.8 ± 1.1 4.3 13 h ch2 / h ca2 0.5-0.8 0.6 ± 0.1 0.6 17 h ca2 / w ca2 4.8-11.9 8.4 ± 2.6 9.6 13 n spines p3 2-3 2 ± 0 2 5 n spines p5 25-31 29 ± 2 29 5

K. & T. von Rintelen , 28 Jul.2004 ; 1 ex. ( MZB Cru 1557), Loeha Island, southwest shore, 02°45.58'S, 121°31.14'E, loc. 149-04, coll. K . & T. von Rintelen , 5 Aug.2004 ; 2 ex. ( MZB Cru 1558, n= 2 juveniles), Loeha Island, west shore, 02°45.5'S, 121°31.06'E, loc. 95-03, coll. K . & T. von Rintelen , 5 Aug.2004 .

Description. – Carapace length 3.0-5.0 mm (n=17). Rostrum ( Fig. 34 A-B, Table 13) long, reaching beyond or far beyond end of scaphocerite, 0.9-1.7 times as long as carapace (n=16), armed dorsally with 14-24 teeth (including 3-5 teeth posterior to orbital margin), anterior less densely spaced, armed ventrally with 5-12 teeth. Antennal spine situated below inferior orbital angle. Pterygostomial angle broadly rounded. Eyes well developed, anterior end 0.6 times length of basal segment of antennular peduncle (n=5). Antennular peduncle 0.9-1.0 times as long as carapace (n=5), second segment 1.4-2.0 times length of third segment, third segment 0.3-0.4 times length of basal segment. Stylocerite reaching 0.9-1.0 times length of basal segment of antennular peduncle (n=5). Scaphocerite ( Fig. 34F ) 3.3-5.4 times as long as wide (n=5).

Sixth abdominal somite 0.5-0.7 times length of carapace (n=18), 1.5-1.9 times as long as fifth somite (n=11), 0.8- 1.0 times length of telson (n=12). Telson ( Fig. 34E,I ) 3.2- 3.6 times as long as wide (n=6), distal margin rounded, without projection, with 3-4 pairs of spinules and 1 pair of dorsolateral spinules; distal end with 3 pairs of spines, lateral pair distinctly longer than intermediate pairs, median pair or median spine shortest. Preanal carina ( Fig. 34C ) with a spine. Uropodal diaeresis ( Fig. 34D ) with 12-16 movable spinules (n=6).

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 present on first pereiopod. Incisor process of mandible ( Fig. 35A ) ending in a row of 3-4 small teeth, molar process truncated. Lower lacinia of maxillula ( Fig. 35B ) broadly rounded, upper lacinia elongated, with numerous distinct teeth and setae on inner margin, palp slender. Upper endites of maxilla ( Fig. 35C ) subdivided, palp short, scaphognathite tapering posteriorly with numerous long, curved setae at posterior end. Distal end of palp of first maxilliped ( Fig. 35F ) triangular, with a finger-like projection; flagellum of the exopod very elongated, endopod high, reaching half the flagellum of exopod in length. Second maxilliped ( Fig. 35E ) typical. Third maxilliped ( Fig. 35D ) with ultimate segment distinctly shorter than penultimate segment.

Chela and carpus of first pereiopod distinctly stouter and broader than chela and carpus of second pereiopod ( Fig. 34 N-P); chela of first pereiopod 2.0-3.6 times as long as wide (n=13), 0.9-1.4 times length of carpus (n=18); tips of fingers rounded, without hooks; dactylus 1.3-1.5 times as long as palm (n=5); carpus 2.1-5.2 times as long as wide (n=12), 1.2-1.5 times length of merus (n=5). Chela of second pereiopod 2.3-5.5 times as long as wide (n=13), 0.5-0.8 times length of carpus (n=17); tips of fingers rounded, without hooks, dactylus 1.3-1.6 times as long as palm (n=5); carpus 4.8-11.9 times as long as wide (n=13), 1.4-1.6 times as long as merus (n=5).

Third pereiopod ( Fig. 34G,K ) slender, dactylus 2.8-4.0 times as long as wide (terminal spine included, without spines of flexor margin; n=5), terminating in one large claw with 2-3 accessory spines on flexor margin; propodus 17.0-23.0 times as long as wide, 7.0-7.8 times as long as dactylus; carpus 6.8-8.9 times as long as wide, 0.5-0.6 times as long as propodus, 0.5-0.6 times as long as merus; merus 10.0-13.4 times as long as wide, bearing 3-4 strong, movable spines on posterior margin of outer surface.

Fifth pereiopod slender ( Fig. 34H,J ), dactylus 3.6-5.4 times as long as wide (terminal spine included, without spines of flexor margin; n=5), terminating in one large claw with 25- 31 accessory spines on flexor margin; propodus 18.7-26.3 times as long as wide, 3.9-7.6 times as long as dactylus; carpus 6.9-8.7 times as long as wide, 0.5-0.6 times as long as propodus, 0.6-0.7 times as long as merus; merus 9.2-11.8 times as long as wide, bearing 2-3 strong, movable spines on posterior margin of outer surface.

Endopod of male first pleopod ( Fig. 34L ) elongated triangularly, 1.8-1.9 times as long as proximally wide (n=5), without appendix interna. Appendix interna of male second pleopod ( Fig. 34.M ) 0.7-0.9 times length of appendix masculina (n=5).

Ovigerous females with 17- 31 eggs (n= 3 females); egg size 1.0-1.1 x 0.6-0.7 mm (n=37, eggs with and without eyes).

Distribution. – Endemic to Lake Towuti and widely distributed within the lake ( Fig. 33A ).

Biology and ecology. – C. spinata is a hard substrate dweller on rocks. Whereas juveniles were also frequently observed in shallow water zones (above approx. 3-5 m), adults seem to prefer boulders in deeper water zones, where they often occur in syntopy with C. profundicola and sometimes with other rock dwellers from Lake Towuti. When disturbed, C. spinata tries to hide in nearby gaps between rocks (usually boulders). Like in other typical rock dwellers from the Malili lakes it rather escapes side- or downwards than in other directions.

Colour pattern. – Body and appendages mainly crimson to deep red ( Fig. 33 B-C), often with two to three bright yellow or orange transversal stripes at the end of the carapace and the abdomen and a few dots of the same colour on various body parts or body appendages, e.g. tips of the uropods. Chelae and uropods can be completely yellow or orange. This combination of red-crimson and yellow or orange is unique in the ancient lake species, although a red body colouration is common in rock dwellers. Antennules usually transparently white. Eggs coloured as body. This colour pattern remains visible even if the shrimp is under stress, the intensity of the colour might fade.

Taxonomic remarks. – Cai et al. (2009: 19) stated: “Specimens of Woltereck (1937a, b) are no longer extant […]. As all new species described by Woltereck are morphologically close to each other and to stabilize the taxonomic status of those species, neotypes are designated if specimens are available from the recent collections”. Consequently, they designated a neotype for C. spinata from Lake Towuti (ovigerous female, cl 4.3 mm, ZRC) (2009: 25) .

In living animals the colour pattern of C. spinata always distinguishes it from all other species. C. spinata (carapace length 3.0-5.0 mm, median 4.2 mm) and C. profundicola (2.7- 4.9 mm, median 4.0 mm) are the largest lacustrine species in the Malili lakes. Both have similarly slender pereiopods and often occur on the same substrate (usually boulders in deeper water) at the same locality. They differ in the shape of the rostrum (not triangular, but rather uniformly slender vs. proximal part triangular while distal part distinctly slender in C. profundicola ), a shorter rostrum compared to the carapace length (0.9-1.7, median 1.2 vs. 1.4-2.8, median 1.9 in C. profundicola ), a smaller number of ventral teeth on the rostrum (5-12, median 9 vs. 13-24, median 20 in C. profundicola ) and on the dactylus of the fifth pereiopod (25- 31, median 29 vs. 34-44, median 39 in C. profundicola ), as well as a higher number of spines on the uropodal diaeresis (12-16, median 14 vs. 9-11, median 10 in C. profundicola ). With regard to the rostrum, C. spinata resembles C. striata , C. glaubrechti and C. woltereckae , but it differs in the slender form of the first and second pereiopods and the generally larger size (carapace length up to 5.0 mm vs. not larger than 3.4-3.8 mm in the other species).

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

Figures

Fig. 33. Caridina spinata from the Malili lake system. A. distribution. B,C. colour pattern of living animals (not to scale). Picture B. courtesy of Chris Lukhaup.

Fig. 34. Caridina spinata from the Malili lake system. A. Cephalothorax and cephalic appendages, male (ZMB 29026); B. Woltereck’s drawing of the rostrum (modified from 1937a); C. Preanal carina, male (MZB Cru. 1556); D. Uropodal diaeresis, male (ZMB 29026); E. telson; F. Scaphocerite, male (MZB Cru. 1556); G. Third pereiopod, female (ZMB 29026); H. Fifth pereiopod; I. Distal end of telson, male (ZMB 29026); J. Dactylus of fifth pereiopod, female (ZMB 29026); K. Dactylus of third pereiopod; L. Endopod of male first pleopod (MZB Cru. 1556); M. Appendix masculina of male second pleopod; N. SEM image of chela and carpus of first and second pereiopods, female (ZMB 29058); O. First pereiopod, male (ZMB 29026); P. Second pereiopod. Scale bars: A, F = 1.0 mm; C, E, G-I, L-P = 0.5 mm; D, J-K = 0.1 mm; B = no scale available.

Fig. 35. Caridina spinata from the Malili lake system. A. Mandible (MZB Cru 1555); B. Maxillula; C. Maxilla; D. third maxilliped; E. second maxilliped; F. first maxilliped. Scale bars: A-F = 1mm.

Fig. 6. Caridina dennerli from the Malili lake system. A. Mandible (ZMB 29024); B. Maxillula; C. Maxilla; D. second maxilliped; E. third 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).