Hugo Campos

Gondwana and neotropical galaxioid fish biogeography

The galaxioids, Southern Hemisphere salmoniforms (i.e. Galaxiidae, Aplochitonidae, Retropinnidae and Pro-totroctidae), are found in Australia, New Zealand, New Caledonia, South America and South Africa, and include 4 families, 11 genera, and about 45 species. Biogeographers have disagreed on the interpretation of this distributional pattern, shared by many Southern Hemisphere taxa. Both ecological and systematic data are important in resolving what has become a controversial topic among students of biogeography.

Population studies of Galaxias maculatus (Jenyns) (Osteichthys: Galaxiidae) in Chile with reference to the number of vertebrae

Resumen G. maculatus presenta dos poblaciones que difieren en el numero de sus vertebras, en el sistema lacustre fluvial de Valdivia, Chile. Una poblacion con un bajo numero de vertebras esta en alopatria en los lagos y la otra con un alto numero de vertebras esta en semi‐alopatria en el estuario. Ambas poblaciones estan en simpatria en el rio. Diferencias entre estas poblaciones se demuestran en el estudio de su dinamica de poblaciones, crecimiento, maduracion gonadal y coeficiente de condicion. Se sugiere un aislamiento reproductivo entre estas poblaciones que proporciona argumentos para reconsiderar la validez de las dos especies de Galaxias descritas por Jenyns (1842) para Sudamerica. Proponemos que la poblacion de alto numero de vertebras corresponde a Galaxias maculatus y la otra con bajo numero de vertebras a Galaxias alpinus.

The biology of the introduced carp cyprinus carpio L., in the river Cayumapu, Valdivia, Chile

Carps were collected monthly, with a net, for one year in the River Cayumapu, Valdivia. The population was mainly constituted by scale carps, followed by mirror carps. Scales were used to determine age and growth. Ten age groups were determined; young populations were found during the warm months and older populations in the cold months. Length‐weight relationship, Condition Factor and Relative Condition factor were studied according to the adaptation of this population to its habitat. The reproduction of this species shows a gonad growth from late Spring till Autumn, then it stabilizes during Winter and spawning begins in early Spring. This gonad cycle is closely related to water temperature. Relative fecundity is related to female length. An average of 120,000 eggs per kg body weight is obtained in the population studied. Carps’ diet is characterized by the grazing of aquatic plants (Egeria densa), preying upon benthic invertebrates, also whey which is dumped into the river by a lacteal industry. A comp...