Fecundity and Sexual Maturity of the Coral Siderastrea siderea at High Latitude Along the Florida Reef Tract, USA

Siderastrea siderea is one of the most abundant corals at high latitude shallow sites along the Florida Reef Tract (25°–27°N). This species is able to tolerate wide seawater temperature fluctuations and sedimentation stress, but its reproductive status at high latitudes and under marginal environmental conditions is poorly understood. The objectives of this study were to evaluate the reproductive potential of S. siderea along a latitudinal gradient (25°–27°N) and to determine if sexual maturity occurs in small (\u3c12.0 cm) S. siderea colonies. Samples of coral tissue were collected in 2007, 2008, and 2009 at three sites along the latitudinal gradient and were processed for histological analysis. Oocyte size, volume, and abundance were used to calculate fecundity. Results showed that fecundity decreased with increasing latitude and that oocyte volume was the major contributing factor to this variation. Mature oocytes were observed in S. siderea colonies at sizes as small as 1.1 cm in diameter. The ability of S. siderea to reach fertility at high latitude areas suggests this species is able to reproduce under marginal environmental conditions; however, reduction in oocyte size could increase local retention of larvae. The presence of mature oocytes in small colonies suggests that stress can reduce somatic growth and shift sexual maturity to smaller colony sizes

Vertebrate Photography: Honorable Mention

https://nsuworks.nova.edu/occ_shuttershark_2010/1021/thumbnail.jp

Black and White Photography: 3rd Place

https://nsuworks.nova.edu/occ_shuttershark_2009/1012/thumbnail.jp

Invertebrate Photography: 3rd Place

https://nsuworks.nova.edu/occ_shuttershark_2010/1008/thumbnail.jp

Reproductive Ecology of Siderastrea siderea: Histological Analysis of Gametogenesis, Spawning, and Latitudinal Fecundity Variation

The health of coral reefs has been decreasing globally due to acute and diffuse anthropogenic impacts. Historically corals have persisted through periods of adverse conditions for coral growth via evolutionary selective processes, making successful sexual reproduction paramount to the future of coral reefs. Little is known about sexual reproduction of Caribbean corals at high latitude, specifically in southeast Florida on the northern most extension of the Florida reef tract. Here, a comprehensive histological analysis of gametogenesis, spawning, and size of sexual maturity is provided for Siderastrea siderea at 26°N (Broward County, Florida, USA), with accompanying analysis of fecundity variation from the upper Florida Keys (25 N) through Martin County Florida (27°N). Histological analysis of tissue samples in combination with lunar, tidal, and temperature cues suggest primary spawning occurs following the new moon of October. Massive and rapid post-spawning oocyte resorption was observed and characterized across both years indicating that spawning is generally incomplete in the study area. Histological observations suggest that size at sexual maturity in a nearshore, high sediment environment may be \u3e20cm2 which is considerably smaller than previously reported. Fecundity decreased by 85% from 25°N to 27°N. Changes in fecundity were not attributed to significant differences in oocyte quantity between regions but to differences in oocyte volume which decreased by 65% from 25°N to 27°N. Drastic decreases in fecundity observed over a relatively small geospatial scale have important implications for regional population structure and connectivity and should prompt a further, multi-species, investigation

Black and White Photography: Honorable Mention

https://nsuworks.nova.edu/occ_shuttershark_2010/1005/thumbnail.jp

Food webs and species biodiversity of the fouling community associated with bivalve aquaculture farms compared to analogous non-farm structures

This study is an initial step critical to assessing interactions of bivalve farms with coastal food webs

Gametogenesis of the Hermatypic Coral Siderastrea siderea in Broward County, FL, USA and the Effect of Bleaching on Fecundity

Massive Caribbean scleractinians are slow to replace themselves in the population due to long life spans, low recruitment, and slow growth rates. Disruption of reproductive synchronicity or reduced fecundity may adversely affect their ability to recover and repopulate degraded areas. Reproductive information on Siderastrea siderea, an abundant Caribbean broadcast spawning species, is particularly sparse. In order to track gametogenesis and identify the time of spawning, tissue samples from S. siderea were collected from August 2007 on a weekly basis until November, when a reduction in gametes, indicative of spawning, was observed. Estimated spawning time was compared with lunar phase as well as water temperature data obtained from permanent digital temperature recorders deployed throughout Broward County to determine if either of these environmental cues affected spawning time. Information on colony condition and presence of bleaching was obtained for each colony sampled. Tissue samples were processed for histological analysis and examined for late stage gametes. Fecundity was estimated from measurements of the volume of oocytes cm-2 tissue and was compared between bleached and unbleached colonies. Initial analysis suggests that S. siderea spawned between November 8 and 11, 2007 which coincided with the new moon on November 9th. Samples collected on the 8th contained both ova and spermaries extruded from the mesenteries into the gastrovascular cavity and un-spawned gametes absorbed by the gastrodermis. Further collections of S. siderea in 2008 will be used to corroborate spawning correlation of S. siderea with lunar period