Two new species of blackwater catfishes are described from Pulau Natuna Besar of the Natuna Archipelago, Indonesia. Silurichthys insulanus (Siluridae), new species, differs from all congeners in having a combination of characters: eye diameter 8% HL; pectoral-fin length 16.0% SL; distinctly humped nuchal profile; 1 branched dorsal-fin ray; body depth at anus 16.0% SL; 54 anal-fin rays; caudal peduncle depth 5.7% SL; caudal fin asymmetrically forked, with 12 principal rays and upper lobe 1.1 times longer than lower lobe; and 50 vertebrae. Clarias rennyae (Clariidae), new species, is distinguished from all Southeast Asian congeners in having a combination of characters: anal-fin length 51.3–56.3% SL; body depth at anus 13.1–13.7% SL; head width 17.9–18.9% SL; distance between occipital process and dorsal-fin origin 6.8–8.9% SL; frontal fontanelle length 17.7–22.5% HL; anterior edge of pectoral spine with 19–31 irregular tiny asperities; and 65–68 total vertebrae. Both new species appear to be endemic to blackwater streams along the western coast of Pulau Natuna Besar.
Bibliographical noteFunding Information:
We thank Kelvin Lim (LKCNHM) for granting us access to specimens under his care, and Peter Ng for valuable insights during early drafts of the manuscript. We are also grateful to Daisy Wowor, Darren Yeo, Leong Tzi Ming, and Lim Cheng Puay for assistance and companionship in the field. Thanks to the handling editor Kevin Conway and an anonymous reviewer for improving the manuscript and timely reviews. This study was supported by funding from the Lee Kong Chian Natural History Museum, an AcRF Tier 1 Grant from the Singapore Ministry of Education (National University of Singapore Grant Number R-154-000-633-112), and the Ah Meng Memorial Conservation Fund (National University of Singapore Grant Number R-154-000-617-720).
© National University of Singapore.
- Clarias rennyae
- Silurichthys insulanus
- Southeast Asia