Reproductive biology of the island grouper (Mycteroperca fusca) in the Canary Islands, northwest coast of Africa

[EN]This is the first time that the reproductive characteristics of Mycteroperca fusca have been analyzed over the whole area of its distribution, using the parameter of the histological analysis of the gonads. This species is a protogynous hermaphrodite with a marked predominance of females (1:4.9). The males and females displayed marked differences in the distribution of the sizes. The females were distributed over all the size ranges analyzed (229-725 mm total length), whereas the males were observed within the larger sizes, as of 428 mm. One transitional specimen (610 mm total length) was observed. The size at which the females first reached sexual maturity was 335 mm total length whereas the size at which 95% of females reached sexual maturity was 398 mm total length. The average size at which 50% of the females had inverted to the male condition was found to be 678 mm total length. The range of sizes at which the process of sexual inversion took place was broad, between 428 and 725 mm total length. The reproductive period was long, almost covering the annual cycle, although the maximum activity was observed between April and October, with a peak in spawning in June-July.

Contribution to the biology and fishery of the deep-water red crab, Chaceon Affinis (A. Milne-Edwards & Bouvier, 1894) (Decapoda, Brachyura, Geryonidae) in deep waters of the Canary Islands (Central-East Atlantic)

[EN] This crab was captured in the whole range of depths sampled, although its highest abundance was found between 600 and 800 m, on muddy-rocky bottoms. Moreover, significant differences were observed in the average weight and length, according to depth of capture, island of origin, and date of survey. In general, the b parameter of length-weight relationship indicates a negative allometric growth pattern, although in some cases it was not statistically different from isometry, particularly in males. Males were heavier, larger, and more abundant in catches than females.