Monday, May 4, 2020

[Ichthyology • 2020] Limia mandibularis • A New Livebearing Fish (Cyprinodontiformes: Poeciliidae) from Lake Miragoane, Haiti

Limia mandibularis 
 Rodriguez-Silva, Torres-Pineda & Josaphat, 2020

Limia mandibularis, a new livebearing fish of the family Poeciliidae is described from Lake Miragoane in southwestern Haiti on Hispaniola. The new species differs from all other species in the genus Limia by the presence of a well-developed lower jaw, the absence of preorbital and preopercular pores, and preorbital and preopercular canals forming an open groove each. The description of this new Limia species from Lake Miragoane confirms this lake as an important center of endemism for the genus with a total of nine described species so far.

Keywords: Pisces, Caribbean, jaw, morphology, endemism, preopercular canal

FIGURE 6. Female of Limia mandibularis sp. nov. (48.5 mm SL) showing coloration in a live specimen.

Limia mandibularis, sp. nov.  

Diagnosis. Limia mandibularis sp. nov. is uniquely diagnosed by the presence of a well-developed lower jaw due to the presence of an elongate anguloarticular bone (Fig. 3). The new species can also be identified by the lack of preorbital and preopercular pores and by the presence of single preorbital and preopercular canals forming open grooves (Fig. 4). Limia mandibularis sp. nov. can be further distinguished by the combination of the following characters: dorsal fin with 8 rays and its origin is slightly behind of the origin of the anal fin in females; 13 predorsal scales; caudal fin symmetrical and truncate or slightly convex; no crossbars, spots or blotches on body in both sexes. ...

FIGURE 7. Habitat where Limia mandibularis sp. nov. was collected. 

Distribution and ecological notes. Limia mandibularis sp. nov. is only known from the north bight of Lake Miragoane in Haiti. The lake seems very isolated in terms of connectivity with other water bodies as we did not see any tributary river or stream, but only mountain springs that lead to the lake. Our observations agree with the classification of Curtis & Hodell (1993) of the lake as an endorheic drainage. The species herein described was collected in a clear water path with slow current exiting the lake. Water temperature was 29.9 °C and water conductivity was 321 microS/cm on the collecting date (June 5th, 2019). The area is characterized by the presence of muddy bottoms and some semi-submerged and submerged vegetation growing near the banks (Fig. 7). Limia mandibularis was sympatric with Gambusia beebei, five other Limia species (L. miragoanensis, L. immaculata, L. nigrofasciata, L. garnieri and L. islai), Nandopsis haitiensis and two species of African cichlids introduced in the lake (Oreochromis aureus and Tilapia sp.). 

Etymology. The specific epithet mandibularis, from the Latin mandibula (jaw), is in reference to the well-developed lower jaw, a character that distinguishes the species.
 The vernacular name “Jawed Limia” is proposed for this species, due to the distinct protuberance that can be seen in the lower jaw.

Rodet Rodriguez-Silva, Patricia Torres-Pineda and James Josaphat. 2020. Limia mandibularis, A New Livebearing Fish (Cyprinodontiformes: Poeciliidae) from Lake Miragoane, Haiti. Zootaxa. 4768(3); 395–404. DOI: 10.11646/zootaxa.4768.3.6