Sperm release behaviour and fertilization in the grass goby

Abstract

Nesting males of the grass goby Zosterisessor ophiocephalus showed bouts, with intervals of c. 30 min duration, of upside-down movements while rubbing its genital papilla onto the ceiling of its burrow. Such behaviour was shown during female courting and spawning, and even after female removal. Observations showed that this behaviour was associated with the release of a sperm trail on the substratum and clumped spermatozoa in water, agglutinated with a mercury-bromophenol blue and PAS positive glycoprotein secretion of the sperm duct glands. Agglutination in the secretion delayed the activation of spermatozoa and contributed a steady supply, for up to 40 min, of motile spermatozoa during prolonged egg laying by the female. Sperm released before egg laying achieved c. 50% fertilization success compared with nearly 100% obtained if the sperm was released during egg laying. The sperm release behaviour may improve the nest owner's reproductive success against intruders or sneakers. It also allows defence of the nest while the female is spawning and may allow the male to court other females in the proximity. 1996 The Fisheries Society of the British Isles

Reproductive biology of the rock goby, Gobius paganellus (Actinopterygii: Perciformes: Gobiidae), on the southern Tunisian coast (Gulf of Gabes)

“…La vesicles revealed seasonal changes according to the sexual cycle; however, the monthly change in SVSI showed that during the spawning period the seminal vesicles have their maximal extensions in January. This is probably due to the role of the seminal vesicles during nest building (Ota et al 1996). The annual variation in the HSI showed that energy storage decreased during the spawning season and increased afterwards.…”

“…So, for most fish species featuring nest guarding behavior, sperm loss is relatively negligible (Ota et al 1996). For the rock goby, the seminal (LT > 12 cm) tienen gónadas relativamente pequeñas, lo que indica una menor producción relativa de espermatozoides y que las vesículas seminales producen y se llenan de grandes cantidades de mucinas que causan su ensanchamiento conspicuo.…”

“…Por ende, para la mayoría de los peces que protegen sus nidos, la pérdida de espermatozoides es relativamente insignificante (Ota et al 1996). Las vesículas seminales de G. paganellus presentaron cambios temporales según el ciclo sexual; sin embargo, el cambio mensual en el ISVS mostró que durante el periodo de desove, las vesículas seminales alcanzan sus máximas extensiones en enero.…”

“…Las vesículas seminales de G. paganellus presentaron cambios temporales según el ciclo sexual; sin embargo, el cambio mensual en el ISVS mostró que durante el periodo de desove, las vesículas seminales alcanzan sus máximas extensiones en enero. Esto probablemente se deba al papel que juegan las vesículas seminales durante la construcción del nido (Ota et al 1996). La vesicles revealed seasonal changes according to the sexual cycle; however, the monthly change in SVSI showed that during the spawning period the seminal vesicles have their maximal extensions in January.…”

The nest-holding grass goby (Zosterisessor ophiocephalus) male adjusts the spawning activity in relation to parasitic nest intrusions

“…The study of the goby spawning behavior has been conducted primarily on one species, the grass goby Zosterisessor ophiocephalus (Ota et al 1996;Scaggiante et al 1999;Mazzoldi et al 2000;Torricelli et al 2000). The large grass goby male adopts the territorial tactic, i.e., it digs and defend burrows under the seagrass rhizomes that are used by females as spawning substrate.…”