Nursery area and size structure of the lemon shark population, Negaprion brevirostris (Poey, 1868), in Los Roques Archipelago National Park, Venezuela

Abstract

The protection of the habitats used by juvenile sharks is a management strategy that has recently caught the attention of fishery biologists. In the present study, we evaluated the population of the lemon shark (Negaprion brevirostris) from Los Roques Archipelago in order to identify the nursery area, describe the size composition, and examine the variation in nocturnal activity of the juvenile individuals. The data analysed came from three different sources: commercial shark fishery, tagrecapture sampling, and visual records. A total of 375 lemon sharks with total lengths between 55 and 281 cm were recorded during the study period. Overall data showed that the area occupied by juvenile lemon sharks was clearly partitioned into primary and secondary nurseries. Additionally, nighttime activity seemed to change according to the size of sharks in the primary nursery, suggesting a reduction of time activity overlapping among juveniles of distinct size/age. Results suggest that the strategy of utilization of the primary nurseries by the lemon shark may lead to important ecological benefits by reducing the competition, predation and natural mortality.

Distribution and length composition of lemon sharks (Negaprion brevirostris) in a nursery ground in southern Cuba

“…Knowledge on shark nursery areas has affirmed their critical role in providing protection from predators and as feeding habitats for early life stages (Heupel and Hueter 2002;McCandless et al 2007). The habitat for juvenile lemon sharks in La Salina is consistent with the conventional description of this species' nursery areas, which include shallow and semi-enclosed marine/ estuarine systems that have been extensively documented mainly in the Bahamas (Gruber et al 1988;Morrissey and Gruber 1993a, b) and areas of the Southwest Atlantic (Tavares et al 2016).…”

Updated taxonomic list and conservation status of chondrichthyans from the exclusive economic zone of Venezuela, with first generic and specific records

“…Nevertheless, the taxonomy of Squatina spp. in the VEEZ requires further investigation, particularly due to the recent description of a new species, S. david Acero, Tavera, Anguila & Hernández , for the Colombian Caribbean coast (Acero et al, ; Vaz & De Carvalho, ). The authors proposed that this species might be distributed from Colombia to Surinam (Acero et al, ).…”

Use of a nursery area by cownose rays (Rhinopteridae) in southeastern Brazil

“…Factors such as recruitment, survival of the parental stock and protection of nursery areas, are important for the stability of populations (Camhi et al, 1998;Dulvy et al, 2014). Despite the concern about the conservation of elasmobranchs, knowledge of nursery areas is still poor (Yokota, Lessa, 2006;Tavares et al, 2016). Thus, the goal of the present study was to assess the potential use of a nursery area by the cownose rays R. bonasus and R. brasiliensis during early stages of life.…”

“…by overexploitation and persistent organic pollutants) (Gelsleichter et al, 2006;Dulvy et al, 2014;Sawyna et al, 2016). Therefore, the identification of critical areas involved in the life cycle of these fish is essential for their management and conservation (Heithaus, 2007;Tavares et al, 2016). Nursery areas of elasmobranchs are usually located in shallow estuarine or coastal areas, where there is protection against predators and abundant food, which enables permanence in the first few months or years of their life (Springer, 1967;Castro, 1993;Heupel et al, 2007).…”