Reproductive biology ofAwaous guamensis, an amphidromous Hawaiian goby

Abstract

SynopsisSpawning season, size at first reproduction, oocyte maturation, and fecundity of Awaous guarnensis, an amphidromous Hawaiian goby, were studied from June 1989 through May 1991 in the Wainiha River, Kaua'i, Hawai'i. Female fish larger than 73 mm standard length (SL) had mature gonads from August through December in 1989 and1990. Gonadosomatic index (GSI) values for mature females ranged from 0.2 to 14.5 during the spawning season. Male fish larger than 64 mm SL had elevated GSI values from June 1989 through December 1989 and from August 1990 through December 1990. Mature sperm were found in two male fish collected in January and February. GSI values for mature males ranged from less than 0.01 to 4.0 in the spawning season. Size-frequency distributions of measurements of vitellogenic oocyte diameters and microscopic observations of oocytes indicated this species has group-synchronous oocyte development. Ovarian maturation stages examined over a 29-month period suggest that members of the stock spawned at different times within the spawning season, although mass spawning events have been documented for this species. Estimates of clutch sizes from nests measured in situ were comparable to estimates of potential fecundity from in vitro examination of ovaries, and indicated that female fish deposited an entire clutch during a spawning event. No evidence for multiple spawning by an individual fish in a single season was found. However, microscopic observations of brown bodies in some ovaries suggested that individual fish probably spawn more than once in a lifetime.

Reproduction and marine life history of an endemic amphidromous gobiid fish of Reunion Island

“…Many gobies have annual reproductive cycles (Ha & Kinzie 1996, Keith 2003, McDowall 2004. We have shown that the spawning season of Cotylopus acutipinnis extends over the major part of the year, with a pause between August and October.…”

Comparative larval development of three amphidromous Rhinogobius species, making reference to their habitat preferences and migration biology

“…Indeed, abundant newly hatched drifting Rhinogobius larvae are collected in plankton nets set along the course of the stream on Okinawa Island, and these larvae occur predominantly during the hours after dusk (Maeda and Tachihara 2010;Yamasaki et al 2011). Although adults of several amphidromous fish species, such as ayu (Plecoglossus altivelis altivelis), common whitebait (Galaxias maculatus), river sculpin (Cottus hangiongensis) and the gobies (Awaous guamensis and Luciogobius ryukyuensis), migrate downstream along the courses of rivers or streams to spawn (Benzie 1968;Goto 1986Goto , 1988Ha and Kinzie 1996;Iguchi et al 1998;Kondo et al 2012), such pre-spawning migrations are not known to occur in the three Rhinogobius species studied here. In addition to our unpublished observations that the egg masses of the three species are commonly found in their usual adult habitats, the fact that the spawned egg mass of R. brunneus was found in the upper reaches of Genka Stream suggests that Rhinogobius species spawn in their usual adult habitats without undergoing pre-spawning migrations.…”

Reproductive Biology and Early Development of Two Species of Sleeper, Eleotris acanthopoma and Eleotris fusca (Teleostei: Eleotridae)1

“…In addition, the mean diameter of ripe oocytes in E. aquadulcis has been reported as being 0.27 mm (Allen and Coates 1990), suggesting that that species may also spawn similarly small eggs. Several other eleotrid fishes (Hypseleotris spp., Ophieleotris aporos, and Dormitator latifrons) and sicydiine gobies and their relatives (Sicyopterus spp., Sicydium punctatum, Stiphodon percnopterygionus, Lentipes concolor, Awaous spp., and Stenogobius hawaiiensis) have been reported to exhibit a similar trend toward small eggs and larvae (Manacop 1953, Dô tu and Mito 1955, Lake 1967, Anderson et al 1971, Todd 1975, Maciolek 1977, Auty 1978, Coates 1992, Kinzie 1993, Bell and Brown 1995, Ha and Kinzie 1996, Dotsu et al 1998, Lindstrom 1999, Yamasaki and Tachihara 2006. These fishes are also highly fecund, which has been demonstrated to be inversely related to egg size (Miller 1984 The reproductive strategy of E. acanthopoma and E. fusca is characterized by high fecundity, small eggs, and small newly hatched larvae; these characteristics are shared with several of the eleotrid fishes and sicydiine gobies mentioned previously.…”

“…The reproductive biology of some sicydiine gobies, typical amphidromous fishes, has been studied intensively; they spawn very small eggs and are highly fecund (Manacop 1953, Dô tu and Mito 1955, Kinzie 1993, Ha and Kinzie 1996, Yamasaki and Tachihara 2006. Although the genus Eleotris is not closely related to the Sicydiinae (Gobiidae), several Eleotris species are also widely distributed among tropical and subtropical insular streams and, together with the sicydiine gobies, have colonized isolated oceanic islands such as Hawai'i (Yamamoto and Tagawa 2000) and French Polynesia (Marquet and Galzin 1992).…”