Reproductive parameters of the shovelnose guitarfish Pseudobatos productus (Ayres, 1856) in Northwest Mexico

Abstract

The shovelnose guitarfish Pseudobatos productus is a major species in batoid catch on the north-western coasts of Mexico. Our goal was to describe the reproductive biology of this species, including morphometric and histological analysis of the gonads. Sampling was carried out on artisanal fishing camps near Bahía Tortugas, Baja California Sur, Mexico. A total of 147 organisms were collected, with a size of 58.9 to 162 cm of total length (TL). The size of first maturity (L50%) was 111.3 cm TL for females, and 102.2 cm TL for males. The sex ratio was 1.42 females per male, but 1:1 for embryos. Positive correlations were found between TL and the number of oocytes, the diameter of oocytes, the uterus height, the oviducal gland height, the oviducal gland width, and the clasper length. We describe four histological zones in the oviducal gland of females, with no sperm storage. Mature testicle lobes showed distinct spermatogenesis stages, ranging from spermatogonia to mature sperm cells.

Keywords

• pseudobatos productus
• morphometry
• sex ratio
• size at maturity
• reproduction