Low cost breeding and hatching techniques for the catfish (Heteropneustes fossilis) for small-scale farmers

The high demand for the stinging catfish (Heteropneustes fossilis) and declining wild stocks led the Centre for Aquaculture Research and Extension of India to look for methods for the culture of the species. This paper presents a low-cost, simple breeding technique developed and tested by the Centre that can be easily adopted by rural farmers.

Fecundity of shortspine thornyhead (Sebastolobus alascanus) and longspine thornyhead (S. altivelis) (Scorpaenidae) from the northeastern Pacific Ocean, determined by stereological and gravimetric techniques*

Fecundity was estimated for shortspine thornyhead (Sebastolobus alascanus) and longspine thornyhead (S. altivelis) from the northeastern Pacific Ocean. Fecundity was not significantly different between shortspine thornyhead off Alaska and the West Coast of the United States and is described by 0.0544 × FL3.978, where FL =fish fork leng th (cm). Fecundity was estimated for longspine thornyhead off the West Coast of the United States and is described by 0.8890 × FL3.249. Contrary to expectations for batch spawners, fecundity estimates for each species were not lower for fish collected during the spawning season compared to those collected prior to the spawning season. Stereological and gravimetric fecundity estimation techniques for shortspine thornyhead provided similar results. The stereological method enabled the estimation of fecundity for samples collected earlier in ovarian development; however it could not be used for fecundity estimation in larger fish.

Traditional and geometric morphometrics detect morphological variation of lower pharyngeal jaw inCoris julis(Teleostei, Labridae)

In the present study, variation in the morphology of the lower pharyngeal element between two Sicilian populations of the rainbow wrasse Coris julis has been explored by the means of traditional morphometrics for size and geometric morphometrics for shape. Despite close geographical distance and probable high genetic flow between the populations, statistically significant differences have been found both for size and shape. In fact, one population shows a larger lower pharyngeal element that has a larger central tooth. Compared to the other population, this population also has medially enlarged lower pharyngeal jaws with a more pronounced convexity of the medial-posterior margin. The results are discussed in the light of a possible more pronounced durophagy of this population.