RELATIONSHIPS OF SUNDASALANX 



23 



Sundasalanx tnesops Siebert and Crimmen, sp.nov. 



(Fig. 13) 



HOLOTYPE. MZB 6098, 20.7 mm SL, Indonesia, Kalimantan 

 Tengah, Barito River drainage, Sungai Laung at desa Maruwei, 0° 

 2 1.986'S, 11 4° 44.1 03'E, miscellaneous catches, 15-18 Jul 1992, D. 

 Siebert, A. Tjakrawidjaja and O. Crimmen. 



Paratypes. MZB 6099 (10), collection data as for holotype. 

 BMNH 1996.7.18.2-51 (50), collection data as for holotype. 



Referred material. BMNH 1996.7.18.52-56 (5), Indonesia, 

 KalimantanTengah, Barito River drainage, small tributary of Sungai 

 Maruwei approx. 1 km upstream from desa Maruwei, 0° 2 1.986'S, 

 1 14° 44.103'E, rotenone, 15 Jul 1992, D. Siebert, A. Tjakrawidjaja 

 and O. Crimmen. BMNH 1996.7.18.57-66 (10), C&S, collection 

 data as for BMNH 1996.7.18.52-56. BMNH 1996.7.18.67-109 

 (43), collection data as for BMNH 1996.7.18.52-56. BMNH 

 1996.7.18.110-146 (37), Indonesia, Kalimantan Tengah, Barito 

 River drainage, Sungai Barito approx. 2 km below Muara Laung, 

 beach seine at dusk, 8 Jul 1992, D. Siebert, A. Tjakrawidjaja and O. 

 Crimmen. BMNH 1996.7.18.312 (1), 26.5 mm, Indonesia, 

 Kalimantan Tengah, Sungai Barito drainage, sand bank of Sungai 

 Joloi upstream from Sungai Busang, seine, 7 Feb 1991, D. Siebert, 

 A. Tjakrawidjaja and O. Crimmen. BMNH 1 996.7. 1 8.3 1 3-314 (2), 

 26.0-29.5 mm, Indonesia, Kalimantan Tengah, Barito River drain- 

 age, sand bars of Sungai Joloi upstream from Sungai Busang, seine, 

 8 Feb 1991, D. Siebert, O. Crimmen, A. Tjakrawidjaja. 



Diagnosis. A photograph of S. mesops is presented as Fig. 13; 

 selected morphometries are summarised inTable 1 and vertebral and 

 fin-ray counts are summarised inTable 2 and Table 3. It is a species 

 of Sundasalanx with a relatively large eye (4.5-5.7% SL, 21.4- 

 27.5% HL); and relatively short snout (15.6-22.9% HL). Vertebral 

 number 40-41 (median=41); dorsal-fin rays 8-10 (median=9); and 

 anal-fin rays 13-16 (median=14). Prepectoral mark well developed; 

 posterior wall of cardiac compartment with melanophores; 

 basipterygium without ring of melanophores. Premaxilla with 3-5 

 teeth; maxilla with 16-18 teeth; dentary with 12-13 teeth in single 

 row; 5th ceratobranchial tooth plate with 3-5 teeth in principal 

 posterior row, teeth anterior to principal row small and few; 3rd 

 pharyngobranchial tooth plate small, with 3 or 4 teeth; 4th pharyngo- 

 branchial tooth plate relatively small, about 1 /3 size of 4th pharyngo- 

 branchial, with principal row of larger teeth along posterior edge. 



Sundasalanx mesops is easily distinguished from its Barito River 

 congeners by size of eye, colour pattern, and upper pharyngeal 

 dentition. The eye of 5. malleti is smaller; the eye of S. megalops is 

 larger (Figs 11-14). Colour pattern features that distinguish it from 

 5. malleti are listed above in the diagnosis forS. malleti. Sundasalanx 

 malleti has larger upper pharyngeal tooth plates, with more teeth; S. 

 megalops possesses fewer teeth in jaws and smaller upper pharyn- 

 geal tooth plates with fewer teeth (see below). Sundasalanx mesops 

 can usually be distinguished from S. platyrhynchus of the Kapuas 

 River, West Kalimantan by dorsal- and anal-fin ray counts (Table 3). 



SEXUAL DIMORPHISM. Cleared and stained materials in which 

 male and female specimens are clearly identifiable reveal Sunda- 

 salanx mesops is sexually dimorphic for colour pattern. Females 

 differ from males in pigmentation of the cardiac compartment and 

 lower caudal-fin lobe. Males have a more intense mark on the lower 

 caudal-fin lobe; the lower caudal-fin lobe of the female specimen 

 with the largest eggs is not as dark as that of males with only partially 

 mature testes. Males with maturing or mature testes also possess 

 pigmentation of the posterior wall of the cardiac compartment which 

 was not observed in any female. 



ECOLOGY. Sundasalanx mesops was captured downstream from 

 creek mouths in shallows over sandy or silty substrates during 

 daylight hours. During a spate specimens were also taken from 

 inundated grassy stream banks. 



Distribution. Sundasalanx mesops was taken from several lo- 

 calities throughout the upper Barito River basin. Central Kalimantan, 

 Indonesia, from the widest variety of habitat sizes. On present 

 evidence it has the widest distribution of Barito River Sundasalanx. 



Etymology. The name mesops, is a combination of meso, Greek 

 for middle, and ops, Greek for eye. It is in reference to the size of its 

 eye relative to other Barito River Sundasalanx species. 



Sundasalanx megalops Siebert and Crimmen, sp. nov. 



(Fig. 14) 



Holotype. MZB 6100, 25.5 mm SL, Indonesia, Kalimantan 

 Tengah, Sungai Barito drainage, sand and silt bank at the mouth of 

 Sungai Sapen, a small left hand tributary of Sungai Joloi above 

 Sungai Busang, seine, 6 Feb 1991, D. Siebert and O. Crimmen. 



Paratype. BMNH 1996.7.18.1; (1), 25.0 mm, C&S, collection 

 data as for holotype. 



DIAGNOSIS. A photograph of 5. megalops is presented as Fig. 14; 

 selected morphometries are summarised inTable 1 and vertebral and 

 fin-ray counts are summarised in Table 2 and Table 3. It is a species 

 of Sundasalanx with a deep head (approximately 9.5% SL); large 

 eye (approximately 6.0 per cent SL, 28% HL); and short snout 

 (snout:eye ratio < 1). Prepectoral mark well developed; posterior 

 wall of cardiac compartment with melanophores; basipterygium 

 without ring of melanophores. Meristics of paratype as follows: 

 vertebral number 41; dorsal-fin rays 10, anal-fin rays 14-15. Pre- 

 maxilla with 2-3 teeth; maxilla with 12-14 teeth; dentary with 8-10 

 teeth, arranged in 2 rows in rear portion of dental arcade; 

 ceratobranchial 5 tooth plate with 5-6 teeth in principal posterior 

 row, teeth anterior to principal row small and few; pharyngo- 

 branchial 3 tooth plate small, with only 2 or 3 teeth; pharyngo- 

 branchial 4 tooth plate small, about 1 /3 size of pharyngobranchial 4, 

 with principal row of larger teeth along posterior edge. 



Sundasalanx megalops is easily distinguished from its Barito 

 River congeners by size of eye (Figs 11-15; Table 1 ), snout length, 

 and colour pattern. Its eye is easily recognisable as the largest. 

 Colour pattern features in which it differs from S. malleti are listed 

 under 5. malleti. Distinguishing features for all described 

 Sundasalanx are presented in Table 4. 



ECOLOGY. Sundasalanx megalops was captured at the mouth of a 

 creek over sandy, silty substrate in flowing turbid water approxi- 

 mately 1.5 m deep. Seining sand and mud bars along Sungai Joloi 

 up- and downstream from its point of capture produced specimens of 

 5. mesops. 



DISTRIBUTION. Sundasalanx megalops was captured from a single 

 locality on Sungai Joloi, a large upper basin tributary of the Barito 

 River, Central Kalimantan, Indonesia. 



Etymology. This species is named megalops, a combination of 

 mega, Greek for large, and ops, Greek for eye. 



Sundasalanx platyrhynchus Siebert and Crimmen, sp. nov. 



(Fig. 15, 16) 



Holotype. MZB 5944 (ex CMK 6979), 19.2 mm SL, Indonesia, 

 Kalimantan Barat, Kapuas River basin, Kapuas R. mainstream 



