4.4 | Population subdivision of Ocyropsis
The high levels of within-species diversity of Ctenophores make theCOI fragment, and possibly mitochondrial sequencing in general, a
good marker for population genetics. Mitochondrial sequencing revealed
many morphologically cryptic but genetically distinct species. Within
Lobata, phylogenetic relationships were better supported and many
cryptic species complexes were revealed for those with both sympatric
distributions and allopatric isolation (Figure 4b).
The genus Ocyropsis was a good example. Currently,Ocyropsis contains two robustly described species, each with two
subspecies based on coloration, including O. crystallina
crystallina and O. maculata maculata. These have sympatric
distributions and were both described from the Atlantic Ocean (near
Europe), but are thought to be distributed worldwide. Two other
subspecies were described from the Gulf of Mexico, including O.
crystallina guttata which we sequenced one specimen form Florida. TheCOI fragment for specimens of O. maculata maculatasequenced from Florida, Australia, and Tahiti were closely related and
all represented one MOTU. In contrast, specimens of O. crystallina
crystallina sequenced from Florida, the Gulf of California, and Hawaii,
represented three distinct lineages. Unfortunately, specimens from other
regions were not available for sequencing. Regardless, theOcyropsis genus represents just one interesting dichotomy where
one subspecies such as O. crystallina crystallina may have many
genetic and morphological distinctions that lead to many named
subspecies, yet O. maculata maculata, a closely related species
within the genus has a nearly worldwide distribution (Johnson et al., in
prep).