Alcuni aspetti della biologia della riproduzione in Spelaeomysis bottazzii Caroli (Mysidacea, Lepidomysidae)

Some aspects of reproduction in the hypogean crustacean, Spelaeomysis bottazzii (Caroli, 1924) (Mysidacea, Lepidomysidae) were studied. Specimens sampled in a brackish well (S = 7-8\%o) of Murge (Apulia, Southern Italy) were examined in the laboratory. Most of the ovigerous females were kept in the dark, at 20 -+ 0,5°C in water taken at the sampling station. As usual in mysidaceans, eggs (8-14 per female, with diameter of 0.64-+0.71 mm), nauplioid and postnauplioid stages successively occur during marsupial development. The duration of the egg stage exceeds two weeks. The entire period of incubation is longer than three months. Such developmental times are longer than in any epigean Mysidacea Mysida species from temperate climates. Furthermore, female S. bottazzii show strongly reduced brood lamellae at moult subsequent to incubation. This has not been described previously in Mysidacea, and is indicative of a breeding strategy that prevents continuous breeding cycles. In fact, females need to reconstitute their trophic reserves, in order to sustain a long incubation in deep and trophically poor groundwaters.