Occurrence, distribution and abundance of Halobates micans Eschscholtz, 1822 (Heteroptera, Gerridae) along the southeastern Brazilian coast

Abstract

Data collected during an oceanographic cruise along the southeastern Brazilian coast from Cape Frio (22° 58' S) and Paraná (27° 50' S) in March 1982 showed that the marine insect Halobates micans occurred along the Southeastern Brazilian Bight, but in lower abundance in low-temperature areas due to the intrusion and upwelling of South Atlantic Central Water, and in low-salinity areas in Coastal Water. Insect capture was higher at night and in the oligotrophic Tropical Water. The number of nymphs and adult females was higher, probably because of an active breeding season during the austral summer. Adult sex ratio was 1.3:1.0 (F:M). Floating gas vesicles of benthic Sargassum spp. and petroleum lumps were used by females for egg-laying.

Distribution and Characteristics of Halobates germanus Population in the Red Sea

“…In general, the sex ratio was highly female-biased during this study. Relatively higher proportion of females than males, resulting in female-biased sex ratios, have also been reported for H. micans (Miyamoto and Senta, 1960;Cheng, 1971;Dias and Lopes, 2009). Cheng (1971) suggests that such predominance of females in the population may be due to their prolonged longevity, permitting them to lay their full complement of eggs.…”

“…An extended lifespan would also increase the chance of finding a suitable flotsam, which is generally scarce in open ocean, for oviposition until some days after egg maturation and mating, a life-cycle strategy important for the reproductive success of the species. Conversely, the predominance of females can also be beneficial for proliferation of the species as each male can mate with several females (Dias and Lopes, 2009).…”