Pathogenic effect of microorganisms on loggerhead eggs

[EN] Different types of fungi and bacteria have been isolated from hatched and non-hatched as well as failed and non-failed eggs in natural sea turtles nests (Marco et al. 2006, Phillott and Parmenter, 2001, Phillott et al. 2001). Microbiota infections are common in artificial incubation activities and they seem to have an important negative impact on embryo development (Phillott, 2002). However, no clear evidences of their pathogenic effects have been described. The aim of this study was to investigate whether fungi and bacteria represent pathogenic agents to sea turtle eggs, and to assess whether there exists a specific period during incubation in which eggs are more susceptible to microorganisms.

Embryonic and larval development of haliotis tuberculata coccinea reeve: an indexed micro-photographic sequence

[EN] First description of the complete embryo and larval development of the Canarian abalone (Haliotis tuberculata coccinea Reeve.) was conducted along 39 stages from fertilization to the appearance of the third tubule on the cephalic tentacles and illustrated in a microphotographic sequence. Eggs obtained by induced spawning with hydrogen peroxide from the GIA captive broodstock were stocked at a density of 10 eggs/mL and kept at 23 0.5 BC for 62 h until the formation of the third tubule. Live eggs and larvae were continuously observed on a 24 h basis at a 3400 magnification under transmitted light. At each stages, specific morphological features, illustrated by microscopic photographs, were described, as well as the time required for their apparition. Fertilized eggs diameter was 205 8 mm (mean SD), whereas length and width of larvae ready to undergo metamorphosis were 216.6 5.3 mmand 172 8.8 mm, respectively. Knowledge on the larval morphological development acquired through this study will contribute to the improvement of larval rearing techniques for this abalone species.