The family Callichthyidae comprises eight genera of fishes widely distributed across the Neotropical region. In the present study, sequences of the mitochondrial genes 12S rRNA, 16S rRNA, ND4, tRNAHis, and tRNASer were obtained from 28 callichthyid specimens. The sample included 12 species of Corydoras, three species of Aspidoras, two species of Brochis, Dianema, Lepthoplosternum, and Megalechi...

Fast-starts are brief accelerations commonly observed in fish within the context of predator-prey interactions. In typical C-start escape responses, fish react to a threatening stimulus by bending their body into a C-shape during the first muscle contraction (i.e. stage 1) which provides a sudden acceleration away from the stimulus. Recently, similar C-starts have been recorded in fish aiming a...

1. A N D E R S O N , R. V. 1978. Hel ico ty lenchus u robe lus n. sp. (Nematoda : Hoplo la imidae) f rom New Brunswick, Canada . Can. J. Zool. 56:1232-1234. 2. JENKINS, W. R. 1964. A rap id cent r i fugal f lotation t echn ique for separa t ing nematodes f rom soil. P l an t Dis. Rept r . 48:692. 3. MAMIYA, Y. 1968. Ro ty lenchus p in i n. sp. (Nematoda: Hoplo la imidae) f rom forest nurs eries...

The bimodal gill(water)/gut(air)-breathing Amazonian catfish Hoplosternum littorale that frequents hypoxic habitats uses "mammalian" 2,3-diphosphoglycerate (DPG) in addition to "piscine" ATP and GTP as erythrocytic O(2) affinity modulators. Its electrophoretically distinct anodic and cathodic hemoglobins (Hb(An) and Hb(Ca)) were isolated for functional and molecular characterization. In contras...

Synchronized air breathing may have evolved as a way of minimizing the predation risk known to be associated with air breathing in fish. Little is known about how the size of individuals affects synchronized air breathing and whether some individuals are required to surface earlier than necessary in support of conspecifics, while others delay air intake. Here, the air-breathing behavior of Hopl...