Pattern, synchrony and predictability of spawning of the tropical abalone Haliotis asinina from Heron Reef, Australia

Abstract

The spawning biology of the tropical abalone Haliotis asinina on Heron Reef, Australia, was investigated to identify putative environmental and endogenous factors controlling spawning. Spawnings by H. asinina were highly regular and, in comparison to most other haliotids and marine invertebrates, frequent and extremely synchronous. These events appeared to be regulated by more than 1 environmental cue. The spawning season of H. asinina extends from October to April and is associated with an increase in water temperature. During the spawning season, recently captured abalone, housed in flow-through aquaria, released gametes for 2 nights every 2 wk during the new and full moons. However, the exact date of spawning did not correlate precisely with the lunar cycle. Occasionally the spawning events between 2 populations of H. asinina on Heron Reef that were 1.5 km apart differed by 1 d, suggesting that differential tidal regimes might influence the date of spawning. The population that was exposed to slightly longer spring low tides occasionally spawned 1 d earlier.In the aquaria, the onset of male spawnings was earlier than the onset of female spawnings by an average of 31 min. The time of spawning of either sex was highly correlated with the evening high tide; males spawned an average of 19 min prior to the high tide, and females spawned 11 min after the high tide. Spawnings were highly synchronous amongst individuals, with 90% commencing spawning within 89 min of the first individual that spawned. A greater percentage of individuals spawned when in the presence of the opposite sex and the frequency of male ejaculation was greater when in the presence of females. Synchronous spawning patterns persisted for 6 wk in H. asinina maintained in aquaria; after this period, spawnings continued but were irregular and asynchronous. We propose that low tide exposure and time of high tide indirectly regulate the date and time of spawning respectively, and that these tidal elements influence the spawning biology of H. asinina by maintaining endogenous rhythms that persist in non-tidal environments for at least 6 wk.

Spawning season, fecundity and proximate composition of the gonads of wild-caught blacklip abalone (Haliotis rubra) from Port Fairy waters, south eastern Australia

“…In H. laevigata and H. cyclobates, the period of maximum gonad growth coincided with that of an abundant food supply (Shepherd and Law, 1974) and optimal feeding possibilities (Shepherd, 1973). More recently, Counihan et al (2001) suggested that the spawning of H. asinina in the Heron Reef, Australia, was associated with an increase in water temperature (October to April), and that other environmental cues, such as the tidal regime, also appeared to play a role.…”

“…The reproductive seasonality of many abalone species from various regions in the world has been studied previously (Boolootian et al, 1962;Tomita, 1967Tomita, , 1968Newman, 1967;Webber and Giese, 1969;Poore, 1970;Young and de Martini, 1970;Tutschulte and Connell, 1981;Capinpin et al, 1998;Counihan et al, 2001). Harrison and Grant (1971).…”

Reproduction and Early Life Ecology of Abalone Haliotis diversicolor in Sagami Bay, Japan

“…Haliotis discus hannai larvae are detected primarily after typhoons or minor storms 33 while H. kamtschatkana and H. rubra are suggested to spawn during calm periods 2,30 . Tanaka 43 concluded that sudden temperature changes induced the spawning of H. discus discus, H. madaka and H. gigantea, while the spawning of H. asinina appears to be triggered by the lunar cycle and/or tidal amplitude 4 . From our results, the spawning of H. diversicolor in Sagami Bay is strongly associated with typhoon events 24 .…”

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“…In this regard, it is important to review, test and define the available options for estimating MI. In haliotids, these indices have been used primarily to evaluate the reproductive status of populations (Boolootian et al, 1962;Webber and Giese, 1969;Poore, 1973;Ault, 1985;Capinpin et al, 1998;Counihan et al, 2001;Litaay and De Silva, 2002;Najmudeen and Victor, 2004;Setyono, 2006). The simplest indicator is calculated by dividing the gonad weight by the total weight of the body, and it is commonly used in haliotids (Setyono, 2006) and other gastropods (Zetina et al, 2000;Morais et al, 2003;Abidli et al, 2012).…”