Gillellus jacksoni Dawson, 1982
Gillellus jacksoni
photo by Baldwin, C.C.

Family:  Dactyloscopidae (Sand stargazers)
Max. size:  2.5 cm SL (male/unsexed)
Environment:  demersal; marine; depth range 0 - 17 m
Distribution:  Western Central Atlantic: Anguilla, St. Barthélemy Island, Union Island, and Aruba.
Diagnosis:  Dorsal spines (total): 17-20; Anal spines: 2-2; Anal soft rays: 28-30. Common amongst Dactyloscopidae: Small, elongate fishes. Head usually broad and deep, body tapering and compressed behind. Eyes on top of head, often protrusible; mouth moderate to large, oblique to vertical; jaw teeth minute, in 2 or more series; no teeth on roof of mouth (vomer and palatines). Opercular opening large, gill membrane free from isthmus; opercles membranous, large, usually overlapping on underside of head, typically fringed above with 2 to 24 fleshy fimbriae. Dorsal fin continuous, with an isolated or semi-isolated anterior finlet, or with 1 to 5 separate anterior rays; dorsal-fin spines 7 to 23; anal-fin spines 2; dorsal and anal fins free or united to caudal fin by fragile membranes; pectoral fins broad-based, usually enlarged in mature males; caudal-fin rays simple or branched; pelvic fins under throat (insertion anterior to pectoral-fin base), with 1 spine and 3 thickened segmented rays; all other rays simple. Head and venter naked, body elsewhere with large cycloid scales (smooth to touch); lateral line high anteriorly, deflecting ventrally behind pectoral fin to continue along middle of side to caudal-fin base where terminal lateral-line scale bears ventrally directed canal. Body coloration, variably pale to strongly pigmented with white, brown, or reddish; some forms with characteristic saddle-like bars crossing back; others plain, mottled, or with indications of lateral stripes. Species distinguished by: dorsal-fin origin on nape; with an isolated or semi-isolated anterior finlet. Segmented caudal-fin rays usually 10. First preopercular canal not branched, with a single distal pore. Upper lip without fimbriae; lower lip fimbriae 2 to 4. Straight lateral-line scales 18 or 19; arched lateral-line scales 22 to 33 (Ref. 52855).
Biology: 
IUCN Red List Status: Least Concern (LC); Date assessed: 18 October 2007 Ref. (130435)
Threat to humans:  harmless


Source and more info: www.fishbase.org. For personal, classroom, and other internal use only. Not for publication.