Reproductive ecology of three ocypodid crabs I. The influence of activity differences on reproductive traits

Abstract

Reproductive traits of three ocypodid crabs, Scopimera globosa, llyoplax pusillus and Macrophthalrnus japonicus, were compared. S. globosa and L pusillus, inhabiting the upper-middle intertidal zone, produced 1-2 large broods per year, whereas M. japonicus, inhabiting the lower intertidal zone, produced 4 5 small broods per year. In S. globosa and L pusillus, ovigerous females remained in their plugged burrows without feeding until their eggs hatched. On the other hand, female M. japonicus fed actively on surface mud while incubating. We concluded that few large broods may be advantageous in crab species that incubate in burrows, whereas continuous small broods may be advantageous in species thai feed actively while incubating.

Reproductive pattern comparison of Uca thayeri Rathbun, 1900 and U. uruguayensis Nobili, 1901 (Crustacea, Decapoda, Ocypodidae)

“…Salmon (1987) suggested when mating was underground the female showed high fecundity (like U. pugilator), but when it happened at the surface, a low egg number was produced (like with U. vocans). Henmi and Kaneto (1989) demonstrated the advantages and disadvantages of incubating eggs inside burrows. For species with large egg masses, that are suitable to mechanical losses when females walk, it represents a very advantageous proceeding.…”

“…These differences were related to many factors: the weather during which females were collected; food availability; multiple spawning (1 a , 2 a or 3 a spawning of reproductive cycle); individual variation on egg production and natural egg losses related to female activity on the surface (Hines, 1982;Henmi and Kaneto, 1989;Costa and Negreiros-Fransozo, 1996). The fact of U. thayeri showing a higher egg production when compared with U. uruguayensis did not confirm the larval supply of the former species was higher.…”

Population biology of the burrowing crab Neohelice granulata, (Crustacea: Decapoda: Varunidae) from a tropical mangrove in Brazil

“…Although the percentage of ovigerous females over the year is the most common technique used to determine the reproductive period of a species (HEMNI & KANETO 1989), the go- (RUFFINO et al 1994, LÓPEZ-GRECO & RODRÍGUEZ 1999, ITUARTE et al 2004. High percentages of females with advanced gonadal development throughout the year indicate that they have good nutrition, suggesting a highly productive environment which supplies nourishment to the crabs.…”

Population biology of llyoplax stevensi (Brachyura. Ocypodidae) on a Kuwait mudflat

“…Ecological work on the Ocypodidae has been concentrated on relatively few genera (Uca: Crane 1975, Icely & Jones 1978, Frith & Brunenmeister 1980, Colby & Fonseca 1984, Thurman 1984, 1987Ocypode: Barass 1963, Hughes 1966, Haley 1972, Jones 1972, Rao et al 1986Dotilla: McIntyre 1968, Hartnoll 1973, Hails & Yaziz 1982, Fishelson 1983Macrophthalmus: Ono 1962,1965, Simons & Jones 1981, Jones & Simons 1982, Henmi & Kaneto 1989Scopimera: Ono 1962, 1965, Yamaguchi & Tanaka 1974, Wada 1981, 1983a, b, c, Suzulu 1983, Henmi & Kaneto 1989. Little has been written about the ecology of Tylodiplax and Zlyoplax, species of which can numerically dominate the shores on which they occur (Al-Taher 1990).…”