Common Name
Totumo Silverside
Year Described
Fowler, 1950
Identification
Dorsal Fin: IV; I, 7-8
Anal Fin: I, 17-18
Pectoral Fin: 13
Lateral Line Scales: 48-49
Predorsal Scales:
Circumferential Scales: 17-20
Transverse Scale Rows: 6
Gill Rakers: 13-16 (lower arch)
Vertebrae:
Body elongate, flat dorsally, and compressed laterally, with two dorsal fins. Eye large. Mouth terminal, strongly oblique, and does not reach the orbit. Premaxilla protractile. Distal end of premaxilla expanded. Premaxilla lacks postmaxillary process. Teeth in both jaws. Rostral sensory system present. Anterior portion of sensory system consists of a pair of L-shaped furrows. Dorsal fins well separated. Spinous dorsal fin origin above anal fin origin (above anal spine). Anal fin long. Sheath on anal fin base rudimentary and reduced to a few scales. Pelvic fin origin well behind pectoral fin base. Axillary scale present (half pelvic length). Pectoral fin short (reaches pelvic base) and high on body. Caudal fin forked. Scales cycloid.
Color
Translucent pale brownish to yellowish above and colorless below. Silvery midbody stripe less than eye diameter. Fins dusky. Tail may be orange-red, especially at the margin.
Size
Maximum size to 64mm SL.
Habitat
Found only in freshwater and brackish estuaries.
Range
Endemic to the Totumo estuary in Colombia.
References
Chernoff, B. 2002. Atherinopsidae (pp 1090-1103). In: Carpenter. 2002. The living marine resources of the Western Central Atlantic. Vol. 2: Bony fishes part 1 (Acipenseridae-Grammatidae). FAO Species Identification Guides for Fisheries Purposes. American Society of Ichthyologists and Herpetologists Special Publication No. 5.
Other Notes
Closely related to the widespread Atherinella brasiliensis and along with A. venezuelae probably evolved from an isolated segregate at the westernmost part of that species range.