Pitcher Silverside, Atherinella nepenthe
The Pitcher Silverside, Atherinella nepenthe, whose common Spanish name is plateadito marino, is a species in the New World Silverside or Atherinopsidae Family, known collectively as charales and pejerreyes in Mexico. Globally, there are thirty-six species in the genus Atherinella, seven of which are found in Mexican waters, two in the Atlantic and five in the Pacific.
The Pitcher Silversides have elongated and relatively deep bodies with a rounded cross section. They are translucent and silvery in color with a silver stripe on their sides that is narrower than the eyes and reaches the caudal fin. Their head has a straight profile with large eyes, a small terminal mouth that opens in the front, and a non-extendible top jaw. Their anal fin has one spine and 24 to 30 rays. Their caudal fin is forked. Their first dorsal fin has 3 to 6 spines and originates over the anal fin origin; their second dorsal fin has 9 to 11 rays and the last dorsal ray is over the last anal fin ray. Their pectoral fins reach the pelvic fin tips. Their pelvic fins are short and do not reach the anus. They are covered with smooth scales.
The Pitcher Silversides are a schooling pelagic species found in shallow intertidal waters, coastal bays, and near coastal reefs from the surface to depths up to 35 feet. They reach a maximum length of 10.0 cm (3.9 inches). They are active daytime feeders that consume algae, small crustaceans, pelagic fish eggs, and pelagic fish larvae. Reproduction is oviparous with large masses of sticky eggs released by females several times per year. These eggs attach themselves to shallow water seaweed via means of long filaments and are then fertilized by males. The larvae are planktonic.
The Pitcher Silverside can be confused with the Broadstripe Silverside, Atherinella nesiotes (broad side stripe wider than eye diameter) and the Longfin Silverside, Atherinella eriarcha (side stripe ends in hourglass shape at tail base).
In Mexican waters the Pitcher Silversides are found from Magdalena Bay southward along the southwest coast of the Baja, from Loreto southward along the southeast coast of the Baja, and along the coast of the mainland from Mazatlán southward to Guatemala.
The Pitcher Silversides are of limited interest to most due to their small size. They are, however, an important food source for a wide variety of fish, marine mammals, and sea birds. They are abundant and widespread and are considered of Least Concern from a conservation perspective, although current population trends are unknown.
Pitcher Silverside, Atherinella nepenthe. Fish provided by the commercial bait salesmen of the greater Los Cabos area, Baja California Sur, January 2011. Length: 8.0 cm (3.1 inches).