Abstract
The early life stages of the cubomedusa Alatina cf. moseri from Osprey Reef (North Queensland, Australia) and Waikiki (Oahu, Hawaii) were studied using laboratory-based culturing conditions. Spawning populations from both regions were observed with reliable periodicity allowing polyp cultures from these locations to be collected and established under laboratory conditions. The polyps of this species were successfully reared from spawning adults. Polyps of Alatina cf. moseri were cultured at temperatures of 23–28°C, developed up to 19 tentacles and reached up to 1.70 mm in height. The balloon-shaped hypostomes possessed 4 well-defined lips. The polyps increased their numbers by means of formation of either sedentary polyp buds or creeping-polyp buds, which attached after 2–3 days. Metamorphosis occurred at temperatures of 25–28°C. Development of polyps and medusae were achieved for the first time within the genus Alatina and allowed comparisons of early life history between these and other species of the Carybdeida families. The metamorphosis and young medusa of this genus showed characters that differed distinctly from those noted for other Carybdeida species, but are very similar to the one described from Puerto Rico by Arneson and Cutress in 1976 for Alatina sp. (named by them Carybdea alata). Based on this evidence, the discrepancies in original specimen descriptions and the previous genetic comparisons, we support the suggestion that the two previously described species of Alatina from Australia and Hawaii (Alatina mordens and Alatina moseri) appear to represent artificial taxonomic units and may in fact be the same as the original Carybdea alata species named from Puerto Rico. Further taxonomic studies are desperately needed in order to clarify the various species and description discrepancies that exist within this newly proposed genus.
Highlights
The early life history has not yet been described for Carybdeida species belonging to the newly formed genus Alatina [1] life cycle knowledge is missing for the majority of the cubozoan species [2] only a small number having descriptions of the early stages of the life cycle [3,4,5,6,7,8,9,10,11,12,13,14,15,16]
The lunar linked periodicity of Alatina moseri (Mayer, 1906) in Hawaii has been documented since the late 1980’s with their predictable arrival on Waikiki beach being reported as the 8th to 10th days after every full moon [2,26,27,28], aggregations of sexually mature Alatina were observed from this site by the first and third author on consecutive monthly cycles from Waikiki Beach in Hawaii on various occasions over the last 10 years leading to the hypothesis of a spawning population
Fertilization & Polyp formation (Table S1) Spawning aggregations have been previously reported in several species of Cubozoa [3,4,6,7,9,12,16,17,32,38,39], the investigations on Alatina sp. ( = Carybdea alata from Puerto Rico Arneson & Cutress [7,8]), Carybdea xaymacana Conant, 1897 [32,40,41], Carybdea sp. ( = Carybdea marsupialis from Puerto Rico, [4,6], Carybdea rastoni Haacke, 1887 [42] [5], Copula sivickisi (Stiasny, 1926) [43] [10,12,15] and Tripedalia cystophora Conant, 1897 [17,20,32,41] have all shown internal fertilization occurs except in Morbakka virulenta (Kishinouye, 1910) where the gametes were released into the open water [16]
Summary
The early life history has not yet been described for Carybdeida species belonging to the newly formed genus Alatina [1] life cycle knowledge is missing for the majority of the cubozoan species [2] only a small number having descriptions of the early stages of the life cycle [3,4,5,6,7,8,9,10,11,12,13,14,15,16]. The lunar linked periodicity of Alatina moseri (Mayer, 1906) (previously Charybdea moseri Mayer, 1906 or Carybdea alata Reynaud, 1830) in Hawaii has been documented since the late 1980’s with their predictable arrival on Waikiki beach being reported as the 8th to 10th days after every full moon [2,26,27,28], aggregations of sexually mature Alatina were observed from this site by the first and third author on consecutive monthly cycles from Waikiki Beach in Hawaii on various occasions over the last 10 years leading to the hypothesis of a spawning population. Within the Alatinidae family there are several species that are under revision and debate continues as to the validity of the different Alatina species [33] in particular and how these relate to the original description of Carybdea alata that was described by Reynaud [34] for a species from the Atlantic Ocean
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