Microbrotula Gosline
Creators: name: M. Eric Anderson
Publisher: name: Zenodo
Year: 2005
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Ophidiiformes
Bythitidae
Microbrotula

description: Microbrotula Gosline, 1953
Microbrotula Gosline, 1953: 218 (type species: Microbrotula rubra Gosline, 1953, by original designation). Cohen and Wourms, 1976: 81 (new diagnosis). Cohen and Nielsen, 1978: 48 (diagnosis; mention of undescribed species). Nielsen and Cohen, 1999: 106 (diagnosis, key).
Included species. Microbrotula comprises five species, M. bentleyi sp. n., M. polyactis sp. n., M. queenslandica sp. n., M. randalli and M. rubra.
Diagnosis. The genus is distinguished from all other Bythitinae as defined by Cohen and Nielsen (1978) by the following combination of characters: Dwarf species reaching only 45 mm SL (M. rubra). Body relatively short, head length 25.7-29.2% SL. Vertebrae 11-13 + 33-44 = 44-56. Dorsal fin retrograde, its origin above vertebrae 7-11, anal-fin origin beneath vertebrae 14-17. Neural spines of vertebrae 4-8 depressed; spine of first vertebra much reduced. Eye small, 6.5-17.5% HL. Anterior nostril with slight tube, located just above upper lip. Rear portion of maxilla ensheathed in M. bentleyi and M. polyactis, free in remaining species, and with small, ventrally-directed projection at lower rear corner. Tongue with short, anterior projection, rounded at tip. Vomerine teeth in two small patches; palatine teeth viliform, in single row. Opercular spine strong, usually imbedded. Developed gill rakers 2-4, with tiny denticles on outer surface. Branchiostegal rays 7. Scales very small, imbricated, present on top of head and cheeks in adults. Lateral line mediolateral, of tiny papillae. Pectoral-fin rays 9-17, set on short peduncle that is higher than long. Pelvic fin of a single ray, its length growth-related but reaching almost to anus in adults. Caudal-fin rays 4-6 except in M. polyactis which has 7-8 rays. Male intromittent organ simple, without ossified or sclerified parts (pseudoclasper).
Key to the species of Microbrotula
1 Pectoral-fin rays 9-11 ................................................................................................... 2
- Pectoral-fin rays 13-17 ................................................................................................. 3
2 Five head pores at interorbital area; predorsal length 40.0-47.6% SL (dorsal-fin origin directly above vertebrae 10-11); prepelvic length 19.9-22.2% SL; distance symphysis of cleithra to pelvic fin insertion 10.7-14.8% HL; lateral scale rows 63-66; anal-fin rays 71-76; total vertebrae 52-56 ................................................................. M. randalli
- No head pores; predorsal length 34.6% SL (dorsal-fin origin above vertebra 7); prepelvic length 23.4-24.6% SL; distance symphysis of cleithra to pelvic fin insertion 26.2- 28.2% HL; lateral scale rows 56-57; anal-fin rays 62-64; total vertebrae 48-49 ......... ............................................................................................................ M. queenslandica
3 Pectoral-fin rays 13-14; caudal-fin rays 4-6; lateral scale rows 54-ca.60; orbit diameter6.5-13.9% HL ......................................................................................................... 4
- Pectoral-fin rays 16-17; caudal-fin rays 7-8; lateral scale rows 47-50; orbit diameter 16.0-18.7% HL ......................................................................................... M. polyactis
4 Vertebrae 11 + 40-41; dorsal-fin rays 81-92; anal-fin rays 72-80; predorsal length 43.5-47.6% SL; orbit diameter 6.5-9.1% HL; fleshy interorbital width 23.8-27.8% HL; lateral scale rows ca. 60 ........................................................................... M. rubra
- Vertebrae 11 + 33-35; dorsal-fin rays 65-71; anal-fin rays 55-59; predorsal length 36.5-41.3% SL; orbit diameter 10.9-13.9% HL; fleshy interorbital width 16.8-19.8% HL; lateral scale rows 54-55 ........................................................................ M. bentleyi
description: Published as part of M. Eric Anderson, 2005, Three new species of Microbrotula (Teleostei: Ophidiiformes: Bythitidae) from the Indo-West Pacific., pp. 33-42 in Zootaxa 1006 on pages 34-35