Species: Bathygobius mystacium, Island frillfin, Island Frillfin Goby
D: 1-3 stripes, edge yellow
C base: 2 dark spots
Bathygobius mystacium Ginsburg, 1947
Island frillfin
Body robust; head broad, depressed, with pores; snout bluntly rounded; eyes large, close together; mouth moderate sized, relatively horizontal, top jaw 9.2-11 (rarely to 11.7) % of SL; tongue is notched; jaw teeth in bands, without canines; teeth in upper jaw in a narrow band, outermost teeth enlarged, without canines; gill membranes broadly joined to body under throat, with 5 rays; dorsal fin VI (none elongate) + I, 8-9; length of 2nd dorsal base > distance from 2nd dorsal base to tail fin; anal I, 7-8; pectoral 17-20, upper 4 (3-5) rays free, silky threads; pelvic fins I, 5, united to form a disc; tail fin rounded; scales large, rough, 35 (33-36) in lateral series, present on midline of nape to well before a line through rear edge of preopercle; no scales on cheek or operculum; no lateral line.
Grayish brown; upper half of body with 3 distinct dark saddles; lower body with a row of 6-7 irregular to squarish, dark, pupil-to eye-sized blotches; 1st dorsal fin with 1-3 dark spotted stripes and a yellow outer edge, sometimes uniform dark in large fish; a large dark blotch on lower 2/3 of tail fin base that joins a small blotch above it on tail base, outer part of tail fin with 3-4 narrow dark bars; yellowish scale edges form zigzag yellow lines along body.
Reaches 7 cm.
Depth range: 0-3 m.
Habitat: shallow sand/rock habitats on the seaward sides of islands.
Florida to the S Caribbean.
High Resolution Map Download
- Salinity
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- Marine Only
- Marine
- Inshore/Offshore
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- Inshore Only
- Inshore
- Water Column Position
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- Bottom
- Bottom only
- Habitat
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- Rocks
- Reef (rock/coral/oyster)
- Sand & gravel
- Reef associated (reef + edges-water column & soft bottom)
- Soft bottom (mud/sand/gravel/beach/estuary/mangrove/seagrass)
- Reef and soft bottom
- FishBase Habitat
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- Reef Associated
- Demersal
- Feeding Group
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- Carnivore
- Data
- Diet
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- Data
- Mobile benthic crustacea (shrimps/crabs)
- Insects
- Egg Type
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- Pelagic larva
- Data
- Benthic
- Global Endemism
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- West Atlantic Endemic
- All species.
- Greater Caribbean endemic
- Regional Endemism
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- Insular primarily
- Continent
- Island (s)
- GC endemic
- Continent + Island (s)
- All species..
- Residency
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- Resident
- Climate Zone
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- Tropical (10-23N, Nicaragua / Cuba)
- Equatorial (0-10N, Costa Rica / Venezuela)
- Subtropical (23-35N, Florida / Carolinas / Bermuda)
- IUCN Red List
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- Listed
- Least concern
- CITES
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- Not listed
- Length Max
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- 7
- Depth Range Min
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- 0
- Depth Range Max
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- 3
