Evolutionary divergence among lineages of the ocean sunfish family, Molidae (Tetraodontiformes)
نویسنده
چکیده
Ocean sunfish, family Molidae, are enigmatic members of the epipelagic fauna of all tropical and temperate oceans. A study, begun in 1998, initially focused on the population genetics of Mola mola Linnaeus 1758 immediately indicated high levels of genetic divergence in the d-loop and cytochrome b mitochondrial genes. This preliminary effort was expanded to include Masturus lanceolatus Liénard 1840, Ranzania laevis Pennant 1776, and representative sequences of other Tetraodontiformes. Analysis of the sequence data confirms that there are two species in the genus Mola, Mola mola and M. ramsayi Giglioli 1883, with the latter presumed to be limited to the southern hemisphere. There is an indication of inter-ocean subdivision within both species originating 0.05–0.32 and 1.55– 4.10 million years ago, respectively. Given limited sample sizes, however, the divergence estimates are minimums and the isolating mechanisms remain speculative. The systematic analysis provided strong support for the sister taxa relationship between genera Masturus and Mola and the basal position of the genus Ranzania within the family, as well as the sister group relationship of the Tetraodontiform families Tetraodontidae + Diodontidae to the Molidae.
منابع مشابه
Molecular and Morphological Identification of Mola Sunfish Specimens (Actinopterygii: Tetraodontiformes: Molidae) from the Indian Ocean
1 Global Career Design Center, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8514, Japan E-mail: [email protected] 2 Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8528, Japan 3 The University Museum, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan 4 Flat Bush, Manukau, Auckl...
متن کاملSeeking the sun in deep, dark places: mesopelagic sightings of ocean sunfishes (Molidae).
Evidence is presented from publicly available remotely operated vehicle (ROV) footage that suggests deep-water ranging in ocean sunfishes (family Molidae) is more common than typically thought, including a new maximum depth recorded for the southern sunfish Mola ramsayi.
متن کاملLeis' conundrum: homology of the clavus of the ocean sunfishes. 2. Ontogeny of the median fins and axial skeleton of Ranzania laevis (Teleostei, Tetraodontiformes, Molidae).
One of the most conspicuous characters of the ocean sunfishes, family Molidae, is the punctuation of the body by a deep, abbreviated, caudal fin-like structure extending vertically between the posterior ends of the dorsal and anal fins, termed the clavus by Fraser Brunner. Homology of the clavus has been a matter of debate since the first studies on molid anatomy in the early 1800s. Two hypothe...
متن کاملPatterns of genome size evolution in tetraodontiform fishes.
We used flow cytometry to measure genome size in 15 species from seven families and subfamilies of tetraodontiform fishes. Previous studies have found that smooth pufferfishes (Tetraodontidae) have the smallest genome of any vertebrate measured to date (0.7-1.0 picograms diploid). We found that spiny pufferfishes (Diodontidae, sister group to the smooth puffers) possess a genome that is about t...
متن کامل