Reproductive patterns of fungiid corals in Okinawa, Japan

Abstract

The reproductive modes of corals in the family Fungiidae are relatively poorly known. In this study we document the findings over five years of observations of various reproductive traits and seasonal reproductive pat terns of 12 species of mushroom corals from northern Okinawa. We provide new records with respect to sexuali ty and mode of reproduction for six species: Ctenactis crassa, Fungia paumotensis, F. scruposa, F. granulosa, Halomitra pileus and Sandalolitha dentata. Furthermore, we indicate two new species that change sex (C. crassa and F. scruposa), as well as identify F. fungites in Oki nawa as a gonochoric brooder. We estimate the reproduc tive effort of C. echinata, C. crassa and F. repanda for the months of July and August of the years 2007-2009, discuss their diurnal rhythms, degree of spawning overlap and the potential for hybridization vs. temporal reproduc tive isolation in these species. We conclude by highlight ing the fungiids as ideal model organisms for studies of reproductive ecology, larval development and the evolu tion of lifehistory traits.

The New Systematics of Scleractinia: Integrating Molecular and Morphological Evidence

“…contigua, P. digitata, P. haimiana, P. nierstraszi, P. profundacella and P. stellata. Crossing experiments are usually performed for broadcast-spawning corals because it is relatively easy to collect eggs and sperm, but are difficult to apply on species that brood, are gonochoric or release daughter colonies asexually. Temporal reproductive isolation has been examined in some fungiids (Loya et al 2009), but for other taxa, detailed morphological analyses with type material combined with molecular methods have been used to define species boundaries, such as in Pocillopora damicornis (Schmidt-Roach et al 2014) and Goniopora stokesi (Kitano et al 2013). Considering that coral spawning usually occurs once a year, it may be prudent to use these approaches on top of crossing experiments.…”

A pre-zygotic barrier to hybridization in two con-generic species of scleractinian corals

“…These species are sympatric, often dominating large multi-specific assemblages of fungiid corals throughout the central Indo-Pacific 8 . Colonies of these species are superficially very similar ( Figure 1A and B) but can readily be distinguished by the shape of the costal dentitions 9 .…”

“…Colonies of these species are superficially very similar ( Figure 1A and B) but can readily be distinguished by the shape of the costal dentitions 9 . Both species are gonochoric, that is each colony is either male or female, and reproduce by broadcast spawning, releasing gametes into the water column for fertilization 8 ( Figure 1C and D). At our study site on Sesoko Island (26°38'13.00"N; 127°51'56.24"E), Okinawa, Japan, spawning occurs following the full moons from July to August 8 .…”

“…Both species are gonochoric, that is each colony is either male or female, and reproduce by broadcast spawning, releasing gametes into the water column for fertilization 8 ( Figure 1C and D). At our study site on Sesoko Island (26°38'13.00"N; 127°51'56.24"E), Okinawa, Japan, spawning occurs following the full moons from July to August 8 . Furthermore, both species release gametes at the same time 8 and consequently there is the potential for hybridization.…”

“…At our study site on Sesoko Island (26°38'13.00"N; 127°51'56.24"E), Okinawa, Japan, spawning occurs following the full moons from July to August 8 . Furthermore, both species release gametes at the same time 8 and consequently there is the potential for hybridization. In the days before the predicted date of spawning in July 2013, we collected four colonies of C. echinata and six colonies of C. crassa , to produce larvae for other experiments.…”