New records of Morid fishes ( Teleostei : Gadiformes ) from the southernmost tip of South America *

Morid fishes include about 100 species, but they are poorly known (Cohen et al., 1990). Within morids the genus Antimora was reviewed by Small (1981). A revision of Lepidion from the North Atlantic was made by Templeman (1970). Nakaya et al. (1980) reviewed Lepidion from the north-western Pacific, and Paulin (1984) indicate new records of Lepidion species from New Zealand. Only Laemonema was recently the subject of a phylogenetic study in which this genus was split in two genera: Laemonema and Guttigadus (Meléndez and Markle, 1997). Howes (1991) studied the biogeography of gadoid fishes and concluded that morid fishes have a wide vertical distribution, are mostly benthopelagic, and Antimora may reach 3000 m depth. During the 1996 Expedition Antarktis XIII/4 of RV “Polarstern” cruise to the Antarctic, passing by the southernmost tip of South America, in May 1996 some specimens of the morid genera Antimora, Guttigadus and Lepidion were caught. These captures are commented in the present paper, as well as a short discussion on the ichthyogeographical significance of their presence on the eastern slope of Isla Nueva, southern Chile. SCI. MAR., 63 (Supl. 1): 465-467 SCIENTIA MARINA 1999


INTRODUCTION
Morid fishes include about 100 species, but they are poorly known (Cohen et al., 1990).Within morids the genus Antimora was reviewed by Small (1981).A revision of Lepidion from the North Atlantic was made by Templeman (1970).Nakaya et al. (1980) reviewed Lepidion from the north-western Pacific, and Paulin (1984) indicate new records of Lepidion species from New Zealand.Only Laemonema was recently the subject of a phylogenetic study in which this genus was split in two genera: Laemonema and Gutti-gadus (Meléndez and Markle, 1997).Howes (1991) studied the biogeography of gadoid fishes and concluded that morid fishes have a wide vertical distribution, are mostly benthopelagic, and Antimora may reach 3000 m depth.
During the 1996 Expedition Antarktis XIII/4 of RV "Polarstern" cruise to the Antarctic, passing by the southernmost tip of South America, in May 1996 some specimens of the morid genera Antimora, Guttigadus and Lepidion were caught.These captures are commented in the present paper, as well as a short discussion on the ichthyogeographical significance of their presence on the eastern slope of Isla Nueva, southern Chile.

MATERIAL AND METHODS
Fishes were collected in May 1996 by the Expedition Antarktis XIII/4-5 of RV "Polarstern" to the Antarctic, with an Agassiz trawl of 1.5 m width and 10mm meshes in the codend.All specimens were fixed in 10% formaldehyde.Measurements and counts follow Templeman (1970) and Paulin (1983).Specimens are deposited at the Instituto de Zoología de la Universidad Austral de Chile (IZUA), the Museo Nacional de Historia Natural, Chile (MNHNC) and the Instituto de la Patagonia, Universidad de Magallanes, Chile.Abbreviation used: Sl = standard length.
These fishes were caught in an area where the sea temperature showed a homogeneous distribution within the first 50 m, between 7 and 8ºC.A thermocline was found between 50 and 100 m.Below this layer, the temperature fluctuated from 5 to 6ºC in the upper part to 2 and 3ºC in the deeper part.Lepidion ensiferus was found living in the lower layer of the thermocline with temperatures around 5ºC; Nakamura (1986) indicated that in the Argentinean Patagonian region where L. ensiferus was caught the water temperatures from 200 to 1000 m depth were 5 to 4ºC.The capture depths for G. kongi and A. rostrata were similar to those found for other specimens elsewhere.A. rostrata seems to live at greater depth.
The records described here were not surprising because of the wide distribution of A. rostrata and G. kongi in the Southern Ocean, however these species were never caught at the southernmost tip of South America before.Lepidion ensiferus was restricted to a narrow belt off Chile at 18º51'S to 19º03'S (Kong and Meléndez, 1991), and was known from the continental slope off Argentina (Cohen et al., 1990).Kong and Meléndez (1991) also reported another specimen of Lepidion from Chile (32º13'S), but they adscribed it to a probable Lepidion microcephalus Cowper,1956.The new captures tend to show more continuity in the distribution of these species, which seem to form part of a belt with particular taxonomic composition in which gadiforms and zoarcids, among other groups, are important components.
If a visual comparison among species is needed, we recommend Cohen et al. (1990) for Lepidion ensiferus and Antimora rostrata and Chiu et al. (1990)