Investigating reproductive ecology and postspawning vitality of Alatina alata population in Bonaire, Dutch Caribbean
Alatina alata is a cubozoan species that forms spawning aggregations eight to ten days after each full moon. From October 2015 to January 2016, we collected jellyfish using handnets during spawning. Individuals were photographed, weighed, and gonad samples were collected to confirm gender in the laboratory. Observations of spawning behavior and postspawning condition of four individuals were made in the laboratory.
The following parameters for spawning aggregations were documented: 1) all individuals were sexually matured (n = 147), 2) female to male ratios are significantly higher than the expected 1:1 for wild populations (χ 2 = 26.017; p ≤ 0.001) with a probability of 0.60.8 female per 0.05 individual encountered, and 3) females (54.8 ± 17.1 g) weigh significantly more than males (48.1 ± 10.2 g) (ttest , p = 0.017). Average wet weight of females is ~14% greater than males. No differences in the ratio of length to width (χ = 29.819; p = 0.991) and wet weight to bell surface area (χ = 29.819; p = 0.999) were found between male and female individuals; indicating that there are no morphological differences. Laboratory observations of spawning showed no evidence of internal fertilization and that postspawning mortality did not occur within 72 hours.