Detection and characterization of diverse coccidian protozoa shed by California sea lions

An unexpected tenant: contamination in a Physeter catodon (Physeteridae, Artiodactyla) genome indicates undescribed species of Sarcocystis Lankester, 1882 (Sarcocystidae, Eucoccidiorida) in the marine environment

Data mining animal of genomes has been used before to identify endoparasites, and may be a particularly useful tool to surpass some difficulties faced by studies in the marine environment. We detected a species of Sarcocystis Lankester, 1882, contamination in the sperm whale (Physeter catodon Linnaeus) reference genome available in the GenBank database. We identified and extracted multiple gene fragments and placed the sequences in a phylogenetic framework. Our results indicate that the sequences of Sarcocystis sp. found in the genome do not correspond to any currently described species, despite a few other similar sequences having been identified in fur seals (Pinnipedia) and another sperm whale. Including data from previous studies, we suggest there is enough evidence to support the occurrence of at least four species of Sarcocystis in marine mammals. We also demonstrate that the term "S. canis-like" has been used for samples not closely related to Sarcocystis canis Dubey et Speer, 1991.

Bacteriological and histopathological findings in cetaceans that stranded in the Philippines from 2017 to 2018

The relatively high frequency of marine mammal stranding events in the Philippines provide many research opportunities. A select set of stranders (n = 21) from 2017 to 2018 were sampled for bacteriology and histopathology. Pertinent tissues and bacteria were collected from individuals representing eight cetacean species (i.e. Feresa attenuata, Kogia breviceps, Globicephala macrorhynchus, Grampus griseus, Lagenodelphis hosei, Peponocephala electra, Stenella attenuata and Stenella longirostris) and were subjected to histopathological examination and antibiotic resistance screening, respectively. The antibiotic resistance profiles of 24 bacteria (belonging to genera Escherichia, Enterobacter, Klebsiella, Proteus, and Shigella) that were isolated from four cetaceans were determined using 18 antibiotics. All 24 isolates were resistant to at least one antibiotic class, and 79.17% were classified as multiple antibiotic resistant (MAR). The MAR index values of isolates ranged from 0.06 to 0.39 with all the isolates resistant to erythromycin (100%; n = 24) and susceptible to imipenem, doripenem, ciprofloxacin, chloramphenicol, and gentamicin (100%; n = 24). The resistance profiles of these bacteria show the extent of antimicrobial resistance in the marine environment, and may inform medical management decisions during rehabilitation of stranded cetaceans. Due to inadequate gross descriptions and limited data gathered by the responders during the stranding events, the significance of histopathological lesions in association with disease diagnosis in each cetacean stranding or mortality remained inconclusive; however, these histopathological findings may be indicative or contributory to the resulting debility and stress during their strandings. The findings of the study demonstrate the challenges faced by cetacean species in the wild, such as but not limited to, biological pollution through land-sea movement of effluents, fisheries interactions, and anthropogenic activities.

Metazoan parasites of California sea lions (Zalophus californianus): A new data and review

The population of California sea lion Zalophus californianus (CSL) has steadily increased during the last several decades. Despite extensive research addressing CSL biology and ecology performed during the last decades, there has been a minimal number of published papers documenting their parasite fauna. Our objective was to analyze the actual list of the metazoan parasites reported from CSLs and add new data on the age-related differences in the prevalence and biodiversity of the parasite community. There have been 33 species recorded but this study considers only 24 of them valid. Among them, 11 species are specific parasites of CSLs and 13 species are not specific. Additional species represent accidental infections or misidentifications. In total, 6653 helminths and 847 mites were collected and identified from 34 CSLs for this study. Six species of nematodes, Anisakis simplex sensu lato s. l. (prevalence 41%; intensity 7.6), Contracaecum ogmorhini s. l. (38%; 269.6), Pseudoterranova decipiens s. l. (29%; 33), P. azarazi (9%; 2.7), Acanthocheilonema odendhali (15%; 3.5) and Parafilaroides decorus were found. Two species of cestodes, Diphyllobothrium sp. (38%; 8.5) and Anophryocephalus sp. (15%; 14.6) represent novel undescribed species. Two species of trematodes, Apophallus zalophi (18%; 19.7) and Zalophotrema hepaticum (12%; 39.2), and five species of acanthocephalans, Corynosoma obtuscens (68%; 100.8), C. strumosum (53%; 4.6), Andracantha phalacrocoracis (3%; 1), Andracantha sp. (9%; 4.3) and Profilicollis altmani (6%; 8.5) were found. Mites Orthohalarchne attenuata (prevalence 85%) were found in the nasal cavity, while O. diminuata (21%) parasitized in the trachea and bronchi. The highest levels of infection with nematodes and trematodes were found in adult CSLs (3-16 years old), whereas the highest level of infection with acanthocephalans was found in young CSLs (pups and yearlings).

Intestinal parasites in Galapagos sea lions (Zalophus wollebaeki) Sivertsen, 1953 on San Cristóbal Island, Galápagos, Ecuador

Knowledge regarding endoparasites of Galapagos sea lions, Zalophus wollebaeki Sivertsen, 1953, is limited to 1 report. Herein, we examined feces extracted from the lower gastro-intestinal tract of 15 Galapagos sea lions (GSL) plus 14 fecal mounds nearby GSL at 4 locations on San Cristobal Island, Galapagos beginning in May continuing through June 2016. Using standard fecal flotation and sedimentation techniques, lungworm larvae, suggestive of Parafilaroides and Otostrongylus sp., eggs of pseudophyllidea cestodes and anisakid nematodes, and coccidian oocysts were collected from study samples. This is the first report of potential lungworm larvae, anisakids, pseudophyllidea cestodes and coccidian parasites in GSL.