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. 2016 Jul 4;6:29198.
doi: 10.1038/srep29198.

Temporal Windows of Reproductive Opportunity Reinforce Species Barriers in a Marine Broadcast Spawning Assemblage

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Free PMC article

Temporal Windows of Reproductive Opportunity Reinforce Species Barriers in a Marine Broadcast Spawning Assemblage

Carla A Monteiro et al. Sci Rep. .
Free PMC article

Abstract

Prezygotic isolating mechanisms act to limit hybridization and maintain the genetic identity of closely-related species. While synchronous intraspecific spawning is a common phenomenon amongst marine organisms and plays an important role in reproductive success, asynchronous spawning between potentially hybridizing lineages may also be important in maintaining species boundaries. We tested this hypothesis by comparing reproductive synchrony over daily to hourly timescales in a sympatric assemblage of intertidal fucoid algae containing selfing hermaphroditic (Fucus spiralis and Fucus guiryi) and dioecious (Fucus vesiculosus and Fucus serratus) species. Our results confirm that gametes are released on semi-lunar cycles in all species. However, sister species with different mating systems showed asynchronous spawning at finer circadian timescales, thus providing evidence for a partial reproductive barrier between hermaphroditic and dioecious species. Finally, our data also emphasize the ecological, developmental, and/or physiological constraints that operate to restrict reproduction to narrow temporal windows of opportunity in the intertidal zone and more generally the role of ecological factors in marine speciation.

Figures

Figure 1
Figure 1. Egg release during 2 h sampling intervals (n = 5 ± SE) by hermaphroditic (circles) Fucus spiralis, Fucus guiryi, and dioecious (triangles) Fucus vesiculosus and Fucus serratus at two replicate sites (open and closed symbols) during four neap tide periods.
Black lines show tidal heights and grey bars the night periods.
Figure 2
Figure 2
Egg release (radial data) relative to timing of day (angular data) by (A) Fucus spiralis, (B) Fucus guiryi, in June (sampling between 05:00 and 22:00 h); (C) Fucus spiralis, (D) Fucus guiryi in July; (E) Fucus vesiculosus and (F) Fucus serratus in June and July at two replicate sites (open and closed symbols). Grey boxes are the dark periods during daily cycle.
Figure 3
Figure 3
Egg release (radial data) relative to tidal level (angular data) by (A) Fucus spiralis, (B) Fucus guiryi, (C) Fucus vesiculosus and (D) Fucus serratus at two replicate sites (open and closed symbols). Grey boxes indicate periods of immersion during the tidal cycles.
Figure 4
Figure 4. Effects of tidal shifts and circadian cycle on egg release by Fucus guiryi and Fucus vesiculosus.
Cumulative egg release (n = 8 ± SE) under (A,E) high tide between 8:00 and 12:00 h; (B,F) high tide between 12:01 and 16:00 h; (C,G) high tide between 16:01 and 20:00 h; and (D,H) constant immersion (no tidal regime). Black and white bars represent the means in each tank. Dark grey bars represent the means in tank with no tidal regime. Different letters above bars indicate significant differences (PERMANOVA, p < 0.05). Light grey shading indicates the night periods and longitudinal lines (black dotted lines) separate the timing of high and low tide periods.
Figure 5
Figure 5. Effects of tidal shifts and circadian cycle on egg release by Fucus guiryi and Fucus vesiculosus.
Cumulative egg release (n = 8 ± SE) under high tide between 8:00–12:00 h, 12:01–16:00 h, 16:01–20:00 h and constant immersion (no tidal). Black and white bars represent the means of egg release at night and day, respectively. Different letters above bars indicate significant differences (PERMANOVA, p < 0.05).

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References

    1. Harrison P. L. et al. . Mass spawning in tropical reef corals. Science 223, 1186–1189 (1984). - PubMed
    1. Levitan D. R. & Petersen C. Sperm limitation in the sea. Trends Ecol. Evol. 10, 228–231 (1995). - PubMed
    1. Pearson G. A. & Brawley S. H. Reproductive ecology of Fucus distichus (Phaeophyceae): an intertidal alga with successful external fertilization. Mar. Ecol. Prog. Ser. 143, 211–223 (1996).
    1. Serrão E. A., Pearson G., Kautsky L. & Brawley S. H. Successful external fertilization in turbulent environments. Proc. Natl. Acad. Sci. USA 93, 5286–5290 (1996). - PMC - PubMed
    1. Clifton K. E. Mass spawning by green algae on coral reefs. Science 275, 1116–1118 (1997). - PubMed

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