Shadows over Caribbean reefs: Identification of a new invasive soft coral species, Xenia umbellata, in southwest Puerto Rico.

In October 2023, several colonies of an alien soft coral species were reported on shallow reefs in southwest Puerto Rico. The soft coral was identified as a xeniid octocoral (species undetermined), resembling the octocoral Unomia stolonifera, which has invaded and overgrown reefs in Venezuela in recent years. To conclusively characterize the species of the invading xeniid, we employed multilocus barcoding targeting four genes (ND2, mtMutS, COI, and 28S) of three separate colonies across three locations in southwest Puerto Rico. Sequence comparisons with xeniid sequences from GenBank, including those from the genera Xenia and Unomia, indicated a 100% sequence identity (>3,000 bp combined) with the species Xenia umbellata (Octocorallia : Malacalcyonacea : Xeniidae). Xenia umbellata is native to the Red Sea and to our knowledge, this represents the first confirmed case of this species as an invader on Caribbean reefs. Similar to U. stolonifera, X. umbellata is well known for its ability to rapidly overgrow substrate as well as tolerate environmental extremes. In addition, X. umbellata has recently been proposed as a model system for tissue regeneration having the ability to regenerate completely from a single tentacle. These characteristics greatly amplify X. umbellata's potential to adversely affect any reef it invades. Our findings necessitate continued collaborative action between local management agencies and stakeholders in Puerto Rico, as well as neighboring islands, to monitor and control this invasion prior to significant ecological perturbation.

Disseminated toxoplasmosis in Antillean manatees Trichechus manatus manatus from Puerto Rico.

Necropsies were conducted on 4 Antillean manatees Trichechus manatus manatus that were stranded in single events on the coastal beaches of Puerto Rico from August 2010 to August 2011. Three manatees were emaciated and the gastrointestinal tracts were devoid of digesta. Microscopically, all manatees had severe widespread inflammatory lesions of the gastrointestinal tract and heart with intralesional tachyzoites consistent with Toxoplasma gondii identified by histological, ultrastructural and immunohistochemical techniques. The gastrointestinal lesions included severe, multifocal to diffuse, chronic-active enteritis, colitis and/or gastritis often with associated ulceration, necrosis and hemorrhage. Enteric leiomyositis was severe and locally extensive in all cases and associated with the most frequently observed intralesional protozoans. Moderate to severe, multifocal, chronic to chronic-active, necrotizing myocarditis was also present in all cases. Additionally, less consistent inflammatory lesions occurred in the liver, lung and a mesenteric lymph node and were associated with fewer tachyzoites. Sera (n = 30) collected from free-ranging and captive Puerto Rican manatees and a rehabilitated/released Puerto Rican manatee from 2003 to 2012 were tested for antibodies for T. gondii. A positive T. gondii antibody titer was found in 2004 in 1 (3%) of the free-ranging cases tested. Disease caused by T. gondii is rare in manatees. This is the first report of toxoplasmosis in Antillean manatees from Puerto Rico. Additionally, these are the first reported cases of disseminated toxoplasmosis in any sirenian. The documentation of 4 cases of toxoplasmosis within one year and the extremely low seroprevalence to T. gondii suggest that toxoplasmosis may be an emerging disease in Antillean manatees from Puerto Rico.

Helminth and arthropod parasites of the brown pelican, Pelecanus occidentalis, in Puerto Rico, with a compilation of all metazoan parasites reported from this host in the Western Hemisphere.

Seven species of helminths and six species of arthropods are reported from 23 of 40 brown pelicans, Pelecanus occidentalis, collected from various localities in Puerto Rico. Helminth parasites include three nematodes (Contracaecum multipapillatum, Contracaecum mexicanum, and Eustrongylides sp.), three trematodes (Galactosomum darbyi, Mesostephanus appendiculatoides, and Ribeiroia ondatrae), and one cestode (Tetrabothrium sulae). Arthropod parasites include Colpocephalum occidentalis, Neottialges apunctatus, Ornithodoros capensis, Phalacrodectus pelecani, Phalacrodectus punctatissimus, and Phalacrodectus sp. The presence of R. ondatrae in the brown pelican is a new species host record, and P. pelecani, P. punctatissimus and N. apunctatus are new subspecies host records. C. multipapillatum, C. mexicanum, G. darbyi and M. appendiculatoides are new locality records for Puerto Rico, and N. apunctatus, P. pelecani, P. punctatissimus and T. sulae are new locality records for the Caribbean. Necrosis produced by C. multipapillatum, C. mexicanum, and R. ondatrae may have contributed to the emaciation and death of the brown pelicans examined in the present study.