Navigobius Hoese & Motomura, 2009, gen. nov.
Creators: name: Hoese, Douglass F.
name: Motomura, Hiroyuki
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Perciformes
Microdesmidae
Navigobius

description: Navigobius gen. nov.   
 Type species: Navigobius dewa sp. nov.   
 Diagnosis. Lower lip with free ventral margin over whole length, fold narrowing at anterior tip of lower jaw; head and body compressed; body elongate; cheek, preoperculum and operculum naked; most of body scaled; most scales cycloid, but with ctenoid patch below pectoral fin and another on posterior region of caudal peduncle, imbricate, in 92–97 vertical rows; mouth terminal, only slightly protrusible, forming an angle of 27–37° to longitudinal axis of body; maxilla reaching posteriorly to below middle of eye; head pores paired laterally, with 4 pores around dorsal margin of each eye; snout relatively short, rounded, its length less than eye diameter; anterior nostril at end of short tube; posterior nostril a simple pore; head papillae in a transverse pattern; median nuchal crest, formed by very low fold of skin, from first dorsal spine onto head to just above middle to posterior end of operculum; gill opening moderate, extending from upper pectoral-fin base ventrally to just below posterior preopercular margin (Figure 2); interorbital about three-quarters diameter of eye; gillrakers on first arch 5+1+10, spatulate, elongate; all rakers ossified, those on second, third and fourth arches tuberculate, with dorsal spiny projections; 2 dorsal fins, first dorsal-fin spines VI, second dorsal-fin rays I,19; anal-fin rays I,19–20; pectoral-fin rays 20; segmented caudal-fin rays usually 9+8; branched caudal-fin rays 6+5; pelvic fins separate, each with rays I,4; vertebrae 10+16; branchiostegals 5.   
 Etymology. from the Latin – navi – to float or swim, an allusion to the swimming habits of the species.   
 Relationships. Navigobius has a mixture of characters found in Ptereleotris, Nemateleotris and Parioglossus. The genus has ctenoid scales posteriorly on the body, a condition also found in Nemateleotris. Other ptereleotrine genera have only cycloid scales. The head canals are completely separate between the eyes, with paired posterior interorbital pores similar to the condition in Aioliops, Oxymetopon, Parioglossus and Pterocerdale gen nov. described below. In Nemateleotris and Ptereleotris the canals are partly fused, with a single median posterior interorbital pore. The dorsal and anal ray counts are higher than those in Aioliops, but lower than those in all other ptereleotrine genera except Parioglossus and the new genus described below. The genus differs from all genera except Aioliops, Nemateleotris and the genus described below in having weakly protrusible (versus highly protrusible) jaws. A detailed comparison of genera not treated here can be found in Rennis & Hoese (1987).   
 Character Nemateleotris Aioliops Oxymetopon Ptereleotris Parioglossus Navigobius Pterocerdale   
Vertebrae 10+16 10+16 10+16 10+16 10+16 10+16 12+16 Longitudinal scale 110–160 0 or 37–44 85–105 100–170 0 or 61–109 97 105  
count  
Body scales cycloid/ cycloid cycloid/ cycloid cycloid cycloid cycloid/ctenoid  
ctenoid ctenoid ctenoid (rarely 1–2  
ctenii on  
some scales
description: Published as part of Hoese, Douglass F. & Motomura, Hiroyuki, 2009, Descriptions of two new genera and species of ptereleotrine fishes from Australia and Japan (Teleostei: Gobioidei) with discussion of possible relationships, pp. 49-59 in Zootaxa 2312 on pages 51-52, DOI: 10.5281/zenodo.191894