Ammocoetes


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Ammocoetes

 

the larva of any of various lampreys (Petro-myzones). In some species the ammocoetes is the same length as the adult form. The body is eel-like, and the mouth is in the form of a triangular cleft. There are no teeth, and the eyes are underdeveloped. The gills are interior, and the fins are unpaired and poorly developed. Ammocoetes live in rivers, streams, and brooks. They spend much of their lives buried in the soil. The larvae feed on small invertebrates and detritus. At the age of three to six years they undergo metamorphosis and become adults.

References in periodicals archive ?
Predatory behavior of Aegla denticulata upon the ammocoetes larval stage of the lamprey Geotria australis in a confined environment.
This species has three ontogeny stages before it reaches its adult stage: 1) Ammocoete (subcutaneous eyes, oral opening with folded lips, without marginal papillae, gill area arranged as furrow with seven undeveloped openings, and a brown colored body), 2) Macroftalmia (developed eyes, inner mouth with fleshy lips and supra and infraoral dental lamina, gill openings exposed to the outside and a dark silver dorsal and ventral body coloration), 3) Hypermetamorphic (semicircular mouth opening, with oral and supra-oral odontoid pieces well-developed, eyes relatively small and covered by translucent membrane, gill opening with folds on each edge, developed dorsal fins, a silver body coloration and a bluish pigmentation on the fins) (Ruiz & Marchant, 2004).
denticulata upon the ammocoete larval stage of the lamprey G.
In addition to chestnut lamprey, Ichthyomyzon ammocoetes were observed at all three sites, and one larval L.
Stream American brook Northern brook lamprey lamprey Saint Joseph River 6 -- Elkhart River 19 -- Little Elkhart River 6 -- Pine Creek 4 -- Yellow Creek -- -- Christiana Creek -- 1 Cobus Creek 7 -- Puterbaugh Creek 8 -- Rock Run Creek 1 -- Rowe Eden -- -- Turkey Creek -- -- Trout Creek 1 -- Baugo Creek -- -- Stream Silver lamprey Adult chestnut Ichthyomyzon lamprey ammocoetes Saint Joseph River 3 59 9 Elkhart River 1 34 6 Little Elkhart River -- 13 7 Pine Creek -- 2 -- Yellow Creek 1 8 -- Christiana Creek -- 7 15 Cobus Creek -- 1 -- Puterbaugh Creek -- -- -- Rock Run Creek -- 2 -- Rowe Eden -- -- 1 Turkey Creek -- -- 3 Trout Creek -- 2 -- Baugo Creek -- 2 --
Kostow (1) reported outmigration of Pacific lamprey (often mixtures of ammocoetes and juveniles) during fall, winter, and spring at locations throughout the Columbia River basin.
This information is especially needed to avoid misidentification of early life stages of lampreys in the field (Mesa and Copeland, 2009), given the often incorrect assumption that all juvenile lampreys are Pacific lamprey (Kostow (1); Mesa and Copeland, 2009) and the difficulties of identifying small ammocoetes to species (Goodman et al., 2009).