Common Name
Chimalapa Silverside
Year Described
Álvarez & Carranza, 1952
Identification
Dorsal Fin: IV; I, 7-10
Anal Fin: I, 27
Pectoral Fin: 12-14
Lateral Line Scales: 35-45
Predorsal Scales:
Circumferential Scales: 20-25
Transverse Scale Rows: 7-9
Gill Rakers: 12-18 (lower arch)
Vertebrae:
Body elongate, flat dorsally, and compressed laterally, with two dorsal fins. Eye large. Snout long. Mouth large, terminal, strongly oblique, and reaches anterior half of eye. Premaxilla protractile. Distal end of premaxilla expanded. Premaxilla lacks postmaxillary process. Teeth in both jaws. Mesopterygoid teeth present. Rostral sensory system present. Anterior portion of sensory system consists of a pair of L-shaped furrows fused medially. Dorsal fins well separated. Spinous dorsal fin origin over anal fin origin. Anal fin long. Sheath present on anterior half of anal fin base. Pelvic fin origin well behind pectoral fin base. Axillary scale present (half pelvic length). Pectoral fin relatively long and high on body. Caudal fin forked. Scales cycloid.
Color
Body pale brownish to yellow, grading to translucent white below. Dark cross-hatching on dorsum. Lateral stripe (thinner than eye diameter) silvery with dark edging. Dorsal and caudal fin yellow to dusky.
Size
Maximum size to 79mm SL.
Habitat
Mostly found in freshwater rivers but also in estuarine river mouths.
Range
Endemic to the rivers entering the Bay of Campeche, Mexico.
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
Sympatric with Atherinella alvarezi but has a noticeably longer snout and larger mouth.