Morphological and histological study of larval development of the Senegal sole Solea senegalensis: an integrative study

Abstract

This study provides a comprehensive description of the main morphological and histological events that take place during larval and post-larval development of Senegal sole Solea senegalensis in order to establish a reference for its normal developmental organogenesis. Five stages have been described. Before gill development at the onset of metamorphosis (eye migration process, stage 4c), the skin was the main site of gas and ion exchange, whereas during stages 3 and 4, the skin begins differentiating into the definitive juvenile structure. The timing of development of the endocrine system depends on each organ, the endocrine pancreas and thyroid gland being the first to differentiate (stages 2 and 3, respectively), followed by the interrenal tissue and stannius corpuscles that develop at metamorphosis (stages 4 and 4c, respectively). The differentiation and maturation of the lymphohaematopoietic organs was coupled with the increase in complexity of the cardiovascular system and the presence of mature erythrocytes (stage 4b), which might be attributed to the change in respiration and the development of fully functional gills. In the differentiation of sensory structures, the development of eyes, inner ear, neuromasts and olfactory organs was rapid, with most of these organs becoming fully developed soon after hatching (stage 1). Vision, chemo- and mechano-reception developed very early in ontogeny, in parallel with the development of the central nervous system and changes in feeding habits. Although the general pattern of development in S. senegalensis appeared similar to most marine fish larvae already described, there were species-specific ontogenetic characteristics probably derived from the species' particular environment (subtropical waters) and behaviour (nocturnal, benthic, omnivorous feeding habits). These results on the organogenesis of larvae are a useful tool for establishing the functional systemic capabilities and physiological requirements of larvae to ensure optimal welfare and growth under aquaculture conditions.

New developments and biological insights into the farming of Solea senegalensis reinforcing its aquaculture potential

“…; Padrós et al . ) and follows the general pattern observed in other marine fish with altricial larval development and particularly that observed in other pleuronectids. However, this species has some important particularities.…”

Ontogeny and functional histochemistry of the digestive and visual systems and other organs during the larval development of the thick-lipped grey mullet, <em>Chelon labrosus</em>

“…During the development and larval growth, the progressive increase of the respiratory surface was noticeable and significant. With age, larvae showed higher branchial functional capability, and the gas exchange across the skin decreased (Rombough 2004, Falk-Petersen 2005, Padrós et al 2011. The kidney and spleen, with excretory, haematopoietic, haemo-catheretic and immune cell structures, were differentiated with similar developmental and physiological patterns to those reported for many other larval fishes (Tanaka et al 1995, Padrós and Crespo 1996, Watts et al 2003, Santamaria et al 2004, Padros et al 2011, and they were well-developed and fully functional at the end of the first month of life.…”

Use of Potato Starch in Diets of Tropical Gar (Atractosteus tropicus, Gill 1863) Larvae

“…The inclusion of potato starch in the diet of A. tropicus larvae could promotes higher activity of amylase and glucosidases, and affects lipase and protease activities. Total digestion capacity of nutrients is required to enhance absorption of products involved in various metabolic processes and morpho-physiological changes during larval development when they experience changes in feeding habits [22]. Detection of increasing levels of carbohydrases together with growth results indicate the potential of including carbohydrates in diets to contribute to the energy supply during larval development of carnivorous fish such as tropical gar [7].…”