A thermal conductivity prediction regression equation was developed for four food materials as a single function of moisture content, porosity and initial thermal conductivity. It was assumed that temperature has a negligible effect on thermal conductivity. Thermal conductivity values of beef, apple, potato, pear and squid were used to develop the regression equation considering 122 points from the literature. The regression coefficient was 0.992. Squid gave the maximum mean per cent deviation of 11.89% (standard deviation 14-39). Potato gave minimum mean per cent deviation of 4.10% (standard deviation 1.74).

Neste trabalho foi descrita a anatomia do esôfago de cada um dos peixes: Hoplías mtabarícus - ictiófago; Prachilodus marggravii e Prochilodus affinis - iliófagos; Leporinus reinhardti; Bryan: lundii e Pimelodus sp. - onívoros. O esôfago destas espécies é curto e tubular. A grande distensibilidade deste órgão, em especial em Hoplias malabaricus, Pimelodus sp. e Brycon lundíi, pode ser atribuída ao padrão da mucosa, a qual é constituída de pregas longitudinais espessas e numerosas. | In this investigation the anatomy of the esophagus of Haplias malabaricus piscivorous, Prochilodus marggravii and Prochilodus affinis- detritivorous, Leporinus reinhardti, Brycon lundii and Pimelodus“ sp. - omnivorous was studied.. The esophagus ef these species is short and tubular. The great distensibility of this organ, especially; in Hoplias malabaricus, Pimelodus sp. and Brycon lundií, can be attributed to the pattern of the mucous membrane which is composed cf thick and numerous longitudinal falas.

Neste trabalho foram estudadas duas diferentes adaptações anatômicas do estômago de peixes de água-doce ao hábito alimentar carnívoro, ictiófago. Em Haplias malabaricus, a região cárdica é longa e, em função do padrão da mucosa, bastante distensível. Em Acestrorhynchus lacustris e Acestrorhynchus britskii é a região cecal que apresenta tais características. | In this study two different anatomic adaptations of the stomach of fresh water fishes to the canivorous, piscivorous feeding habit were invesligated. In Hoplias malabaricus, the cardic region is long and, due to the pattern of the mucous, very distensible. In the Acestrorhynchus lacustris and Acemorhynchus brítskii, it is the caecal region that presents these characteristics.