Tuesday, July 19, 2011

[Ichthyology • 2010] Oryzias hadiatyae • new ricefish (Adrianichthyidae) endemic to Lake Masapi, Central Sulawesi, Indonesia

Oryzias hadiatyae - Holotype

A new species of ricefish is described from Lake Masapi, a small satellite lake of the Malili Lakes system in Central Sulawesi, Indonesia. Oryzias hadiatyae, new species, is known only from this single lake. It differs from all other adrianichthyids in Sulawesi in having a well marked concavity on the snout, a slender but relatively wide body with elongated snout and slightly upwardly directed mouth, pelvic fins with 5–6 fi n rays and anal fi n with 19–22 fi n rays, both inserting relatively close to the rear end of the body, dorsal fin with 8–10 rays inserted above 10–12th anal fi n ray, 28–30 vertebrae, only 27–31 lateral scales, dark brown blotches on the lateral body in adult males, and no blotches in females. This brings the number of ricefi sh species in Sulawesi to 16 (four Adrianichthys, 12 Oryzias), with four endemic lacustrine Oryzias in the Malili Lakes system. In addition, the riverine ricefi sh Oryzias celebensis, known so far only from Sulawesi’s southwestern arm and a single river in East Timor, is here reported for the fi rst time from a drainage in Central Sulawesi.

KEY WORDS. – Oryzias, taxonomy, Sulawesi, Malili Lakes, freshwater fish, endemism.

Oryzias hadiatyae, new species
(common name: Renny’s ricefish)

Material examined. –
Holotype - MZB 18491 (34.2 mm SL), male, Indonesia, Sulawesi: South Sulawesi Province; Larona drainage; Lake Masapi, southern shore between 2°50.837'S 121°21.116'E and the lake’s outlet, approx. 600 m westwards of this position; F. Herder, J. Pfaender, J. Schwarzer & R. K. Hadiaty 15–16 Apr.2004

Etymology. – The specific name, hadiatyae, honors Renny Kurnia Hadiaty who contributed significantly to the exploration of fi sh diversity in the Malili Lakes area. Renny also discovered this endemic ricefi sh in remote Lake Masapi.

Fig. 1. Map of the Malili Lakes system and adjacent drainages. Arrows highlight Lake Masapi, the type locality of endemic Oryzias hadiatyae with River Pongkeru draining the lake to River Larona, and Laroeha, sampling location of Oryzias celebensis at a tributary of Rivers Wewu / Cerekang.

Herder, F. and Chapuis, S. 2010. Oryzias hadiatyae, a new species of ricefish (Atherinomorpha:
Beloniformes: Adrianichthyidae) endemic to Lake Masapi, Central Sulawesi, Indonesia. The Raffles Bulletin of Zoology, 58: 269-280.: http://rmbr.nus.edu.sg/rbz/biblio/58/58rbz269-280.pdf