Balaenophilus umigamecolus are reported for the first time in the eastern Pacific, from the Jalisco coast of western Mexico. Two new hosts are represented: the olive ridley turtle, Lepidochelys olivacea, and the black turtle, Chelonia mydas agassizi. Data indicate a distinct correlation between the presence of B. umigamecolus copepods and Stomatolepas praegustator, barnacles that grow imbedded in turtle skin. This relationship may have implications for marine turtle health. Balaenophilus umigamecolus se divulgan para la primera vez adentro el Pacífico del este, de la costa de Jalisco de México occidental. Se representan dos nuevos anfitriones: la tortuga golfina Lepidochelys olivacea (Olive Ridley), y la tortuga negra, Chelonia mydas. Los datos indican una correlación distinta entre la presencia de los copepodos B. umigamecolus y del Stomatolepas praegustator, los balanos que crecen encajados en piel de la tortuga. Esta relación puede tener implicaciones para la salud de la tortuga marina.

There is a wealth of published information on the epibiont communities of sea turtles, yet many of these studies have exclusively sampled epibionts found only on the carapace. Considering that epibionts may be found on almost all body-surfaces and that it is highly plausible to expect different regions of the body to host distinct epibiont taxa, there is a need for quantitative information on the spatial variation of epibiont communities on turtles. To achieve this, we measured how total epibiont abundance and biomass on olive ridley turtles Lepidochelys olivacea varies among four body-areas of the hosts (n = 30). We showed that epibiont loads on olive ridleys are higher, both in terms of number and biomass, on the skin than they are on the carapace or plastron. This contrasts with previous findings for other hard-shelled sea turtles, where epibionts are usually more abundant on the carapace or plastron. Moreover, the arguably most ubiquitous epibiont taxon for other hard-shelled sea turtles, the barnacle Chelonibia spp., only occurred in relatively low numbers on olive ridleys and the barnacles Stomatolepas elegans and Platylepas hexastylos are far more abundant. We postulate that these differences between the epibiont communities of different sea turtle taxa could indicate that the carapaces of olive ridley turtles provide a more challenging substratum for epibionts than do the hard shells of other sea turtles. In addition, we conclude that it is important to conduct full body surveys when attempting to produce a holistic qualitative or quantitative characterization of the epibiont communities of sea turtles.

The barnacles Stomatolepas elegans and Stomatolepas praegustator are epibionts of sea turtles. The former is described as inhabiting the external skin of turtles and the latter the inside of the mouth and gullet. This study evaluated genetic divergence among 69 traditionally defined individual S. elegans and six individual S. praegustator from 18 sea turtles representing four host species and five geographic locations in the Atlantic and Pacific Oceans. Genetic variation was compared for a 658-base-pair portion of the mitochondrial cytochrome c oxidase subunit I gene locus. Our findings indicate that S. praegustator may be a junior synonym of S. elegans and that selection of hosts is variable. Results also suggest genetic exchange between the Atlantic and Pacific Oceans post-dating separation of the oceans by the Isthmus of Panama, and that species-level complexity for S. elegans may be greater than currently recognized.

First sampled in the late 1990s, Campamento Tortuguero La Gloria, in Jalisco, Mexico, was resampled for olive ridley sea turtle (Lepidochyles olivacea Eschscholtz) diversity 10 years later. A comparison with all previously reported mitochondrial sequences revealed that these new samples added to the known genetic diversity for this species, and revealed unexpectedly high genetic diversity among turtles nesting on this beach. The results highlight the importance of systematic resampling in known nesting rookeries to verify the genetic diversity of study populations. Three new olive ridley haplotypes are reported, all more closely related to Baja Californian haplotypes than to Australian haplotypes. Significant genetic divergence is reported within populations, within ocean basins (Atlantic, Pacific, Indian and Indo-Pacific), and between ocean basins. Furthermore, this is the first study that integrates satellite tagging data to demonstrate diverse post-nesting migration patterns of turtles with identical haplotypes, and it demonstrates flexibility in post-nesting migratory behaviour for olive ridley sea turtles of the same genetic provenance.

In spite of numerous references to Tretanorhinus as a natricine or natricid snake, significant characters of the dentition, vertebrae, hemipenis, and scutellation agree with previous immunological data which indicated that Tretanorhinus is a member of the Central American Dipsadidae. The karyotype of Tretanorhinus variabilis supports the view that this genus is not a natrid.