First record of albinism in the smooth dogfish Mustelus Schimitti Springer, 1939 (Carcharhiniformes - Triakidae) from Southern Brazil

Mustelus Schimitti Springer, 1939 (Carcharhiniformes - Triakidae) from Southern Brazil

Simone Ferreira Teixeira¹ and Maria Lúcia Góes de Araújo2^{* 1} Universidade Federal de Pernambuco; Departamento de Oceanografia; Laboratório de Nectologia; Av. Arquitetura, s/n.; CEP 50.670-901; Recife - PE - Brazil; e-mail: [e-mail]. ² Universidade Federal do Amazonas; Departamento de Morfologia; Laboratório de Embriologia; Av. General Rodrigo Octávio Jordão, 3000; CEP 69.000-000; Manaus - AM - Brazil; e-mail: [e-mail]

ABSTRACT

This paper reports on a subadult male specimen of the smooth dogfish, Mustelus schimitti, caught in the continental shelf of Rio Grande Sul, during winter of 1993, which exhibited the characteristics of total albinism.

Key Words: Albinism, Mustelus schimitti, Carcharhiniformes, Triakidae

INTRODUCTION

Albinism is a genetics abnormality quite rare in Elasmobranch fishes. This phenomenon has been reported in Rhinoptera bonasus (Schwartz, 1959; Joseph, 1961), Sphyrna lewini (McKenzie, 1970) Stegostoma fasciatum (Nakaya, 1973), in embryos of Mustelus californicus (Talent, 1973), Triakis semifasciata (Follett, 1976), Dasyatis americana (Schwartz and Safrit Jr., 1977) and Carcharhinus amboinensis (McKay and Beinssen, 1987/1988). Nakaya (1973) reported albinos or semi-albinos for four species (Notorynchus maculatus, Raja clavata, Raja naevus and Raja batis).

This paper reports a first record of total albinism in Mustelus schimitti from the continental shelf of Southern Brazil.

MATERIALS AND METHODS

During the winter of 1993 by the vessel "Nossa Senhora do Carmo" in the continental shelf of Rio Grande Sul (33° 08’S, 50° 47’ W) at 58 m deep, an albino smooth dogfish Mustelus schimitti was caught. This specimen was preserved in 10% formalin. Morphometric comparisons were made between the albino and normal specimens. Body measurements were made according to Compagno (1984). All the measurements were taken after the fixation in formalin.

RESULTS AND DISCUSSION

The albino specimen was a subadult male (Figure 1), measuring 585 mm of total length (TL) and 775 g. Its age was estimated to be 2.5 years by the equation:

Lt= 820 ( 1 - e ^{- 0,378 ( t + 0,917 )} ) (Batista, 1988).

The albino’s measurements followed the same model of the normal specimen, except the first dorsal fin which had the anterior margin smaller and shorter, with difference of 3.04% for male and 3.94% for female. Maximum difference was in the clasper length with 5.10%. The color of normal specimen is gray above light below with numerous white spots (Figure 2). On the other hand, the albino specimen presented the dorsal and ventral surface completely indistinguishable, both white; the irises of the eyes were pink. So we concluded that this specimen was a total albino.

ACKNOWLEDGMENTS

We thank Ana Catarina Oliveira for her assistance with the albino specimen and the crew of the vessel Nossa Senhora do Carmo for the informations about the capture.

RESUMO

Este trabalho registra a primeira ocorrência de albinismo total no cação Mustelus schimitti, capturado, no inverno de 1993, na plataforma continental do Rio Grande do Sul.

Received: January 02, 2001;

Revised: April 05, 2001;

Accepted: August 03, 2001.

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^*

Author for correspondence

Publication Dates

• Publication in this collection
  27 Sept 2002
• Date of issue
  June 2002

History

• Accepted
  03 Aug 2001
• Reviewed
  05 Apr 2001
• Received
  01 Feb 2001