Larvae of two commercially important fish species, namely southern hake (Merluccius australis) and hoki (Macruronus magellanicus), are described for the first time from material collected in southern Chile. Observations on a third species, blue whiting (Micromesistius australis), are also provided. The three species demonstrate larval characteristics typical of gadiform fishes, including a short gut, and pigmentation distributed in blotches and bands. Characteristics of the larvae of M. australis from Chile are similar to those observed in sketches from New Zealand, such that the descriptions may be used to identify the larvae from other regions. The similarity of characteristics between M. magellanicus larvae from Chile and Argentina and larvae of M. novaezelandiae from Tasmanian and New Zealand waters demonstrate the taxonomic affinity between these species. The presence of three dorsal fins in a late postflexion Micromesistius australis larva allowed it to be easily recognised.

Resumen.-En este trabajo se revisa la información del calderón gris Grampus griseus en aguas chilenas. En base al análisis de 44 registros, la distribución a lo largo de la costa chilena parece ser continua entre los 20º13' S y 40º S, sugiriendo que los registros más australes en Chile (~52ºS) podrían corresponder a calderones grises provenientes del Océano Atlántico. Los registros en Chile muestran un aumento durante el verano austral e indican una preferencia por aguas sobre los 1000 m de profundidad. Varamientos masivos, interacciones con pesquerías y asociaciones con otras especies de cetáceos son también revisadas. Palabras clave: Calderón gris, Grampus griseus, distribución,

Two species of grenadier, the blue grenadier (or hoki) Macruronus novaezelandiae and the Patagonian grenadier M. magellanicus, have been recorded in the Southern Hemisphere with disjunct distributions along southern Australia-New Zealand and southern Chile-Argentina, respectively. The extent of genetic difference between these two putative species was examined using partial sequences (n = 44; 405 bp) of the mitochondrial DNA cytochrome b gene in a phylogenetic analysis and in an analysis of molecular variance (AMOVA). Our analysis showed a lack of genetic differentiation between species (F ST = -0.02275, Φ ST = -0.00250) and among stocks. This absence of genetic differences is consistent with recent larval and adult morphology data suggesting that the two species should be synonymised. A comparable lack of genetic isolation has been observed in other closely related taxa (genera Merluccius and Micromesistius) with similar disjunct distributions across the Southern Hemisphere.

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