Ernest H. Williams

Sea surface temperatures and coral reef bleaching off La Parguera, Puerto Rico (northeastern Caribbean Sea)

Abstract Much recent attention has been given to coral reef bleaching because of its widespread occurrence, damage to reefs, and possible connection to global change. There is still debate about the relationship between temperature and widespread bleaching. We compared coral reef bleaching at La Parguera, Puerto Rico to a 30-y (1966–1995) record of sea surface temperature (SST) at the same location. The last eight years of the La Parguera SST record have all had greater than average maximum temperatures; over the past 30 y maximum summer temperature has increased 0.7 °C. Coral reef bleaching has been particularly frequent since the middle 1980s. The years 1969, 1987, 1990, and 1995 were especially noteworthy for the severity of bleaching in Puerto Rico. Seven different annual temperature indices were devised to determine the extent to which they could predict severe coral bleaching episodes. Three of these, maximum daily SST, days >29.5 °C, and days >30 °C predict correctly the four years with severe bleaching. A log-log linear relationship was found between SST and the number of days in a given year above that SST at which severe coral beaching was observed. However, the intra-annual relationship between temperature and the incidence of bleaching suggests that no one simple predictor of the onset of coral bleaching within a year may be applicable.

Metazoan Parasites and Other Symbionts of Cetaceans in the Caribbean

The parasite fauna in cetaceans from Puerto Rico, the Virgin Islands, and the larger Caribbean region is poorly known. We provide the first records for parasite biodiversity among a diverse assemblage of cetaceans from the Caribbean Sea. Internal and external parasites and commensals were collected from stranded whales and dolphins salvaged in Puerto Rico, the United States and British Virgin Islands, Jamaica, and Venezuela between 1989 and 1997. A total of 47 individuals of 16 species of whales and dolphins (15 odontocetes and 1 mysticete) was examined. Overall, parasites and commensals were found in 34 (72.3%) animals, representing 13 species of odontocetes and 1 mysticete. Eighteen species of endoparasitic helminths were found, including 8 species of nematodes, 2 digeneans, 6 cestodes, and 2 acanthocephalans. Three species of whale-lice and 2 species of barnacles were also collected.

Ability of Pederson cleaner shrimp to remove juveniles of the parasitic cymothoid isopod, Anilocra haemuli, from the host.

Eight species of prospective cleaners, four fishes (sharknosed goby Gobiosoma evelynae, and juveniles of bluehead (wrasse) Thalassoma bifasciatum, Spanish hogfish Bodianus rufus and gray angelfish Pomaccanthus arcuatus) and four shrimps (cleaner shrimp Lysmata grabhami, Pederson cleaner shrimp Periclimenes pedersoni, banded coral shrimp Stenopus hispidus and golden coral shrimp Stenopus scutellatus) were evaluated in aquaria for their ability to remove newly settled juveniles of the fish-parasitic cymothoid isopod Anilocra haemuli from French grunts Haemulon flavolineatum. Periclimenes pedersoni removed all isopods almost immediately. No other cleaners removed any isopods over a 24 hr challenge period. This study is the first evidence that cleaner shrimps can remove juvenile cymothoid isopods.

Digenetic trematodes of marine fishes of Okinawa, Japan

Between May and September 1985, 348 fishes representing 50 families, 107 genera, and 152 species from the coastal waters of Okinawa were examined for digenetic flukes. Ten families (Lepocreadiidae, Opistholebetidae, Gyliauchenidae, Fellodistomidae, Acanthocolpidae, Opecoelidae, Bucephalidae, Cryptogonimidae, Syncoeliidae, and Hemiuridae), representing 29 genera and 34 species of digenetic flukes were recorded. Seven new geographic locality records and 25 new host records were established. Possibly 2 new species, one being a species of the genus Metadena from Meiacanthus grammistes and the other a species of the genus Mesolecitha from Plectorhynchus chaetodontoides, were detected. Most infections were of a single species, and although prevalence and intensity were low, host specificity was high. Only 3 of the 34 species identified transgressed family bounds in their definitive hosts.

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.

Influence of collection methods on the occurrence of alimentary canal helminth parasites in fish

The effect of collecting trauma on the metazoan parasites in the alimentary canal of French grunts, Haemulon flavolineatum (Desmarest) (Perciformes: Haemulidae), was evaluated by comparing the number and species of parasites in 10-fish lots that were identical except for collecting technique. Collecting techniques included speared (dead), speared through the caudal peduncle (live), trapped, dipnetted at night, and ostracitoxin exposed. Dead, trapped, and toxin-stressed fish had no alimentary canal parasites, whereas speared-live and night-dipnetted fish had comparable numbers of parasites. Fish collected by using apparently traumatic techniques quickly expelled their alimentary canal metazoan parasites. Our results cast doubt on the reliability of traditional fish parasite surveys, studies on population dynamics of fish parasites, and experiments that employ these traumatic collecting methods.

HABITAT AND SPECIES DIFFERENCES IN PREVALENCE AND INTENSITY OF NEOBENEDENIA MELLENI (MONOGENEA: CAPSALIDAE) ON SYMPATRIC CARIBBEAN SURGEONFISHES (ACANTHURIDAE)

Abstract We quantified Neobenedenia melleni from the skin of Caribbean surgeonfishes (Acanthuridae) from June through October 2005 and 2007. Prevalence, or mean intensity of infection, or both, varied significantly among the 3 species, and among sites and between years for the most heavily infected species, blue tang (Acanthurus coeruleus). Among 6 sites sampled, no more than 12% of ocean surgeonfish (Acanthurus bahianus) were infected, compared with 10 to 100% of A. coeruleus. The prevalence of infection among doctorfish (Acanthurus chirurgus), collected at only 1 of the sites, was intermediate between the other 2 species (46%). Mean intensity (range) of infection for the few infected A. bahianus was 1 (1) to 3 (1–8), compared with 1.3 (1–2) to 14.3 (1–59) for A. coeruleus, and 2.5 (1–8) for A. chirurgus. Expected abundance of N. melleni on A. coeruleus from shallow bay sites was greater than for those from non-bay sites. Higher infections on A. coeruleus may be attributable to differences in habitat use, or susceptibility to infection, or both, compared to other species. Among site and between-year differences may be associated with differences in benthic habitat, or water conditions, or both. This system seems ideal for future comparative studies on the relationship between environmental variables and parasites on Caribbean coral reefs.

Does lymphocystis occur in pacora, Plagioscion surinamensis (Sciaenidae), from Colombia?

A lymphocystis-like condition produced hemorrhagic lesions over the bodies of pacora Plagioscion surinamensis (Bleeker) (Perciformes: Sciaenidae) held in freshwater aquaculture in northern Colombia and increased their sensitivity to handling stress. This disease eliminated this fish from a project evaluating its aquaculture potential. Lymphocystis disease is assumed to be less damaging to the host. This condition requires more study and histological evaluation.

Angiodictyum mooreae n. sp. (Digenea: Microscaphidiidae) and other digeneans from an Atlantic hawksbill turtle Eretmochelys imbricata imbricata from Puerto Rico.

Abstract A specimen of the endangered hawksbill sea turtle, illegally speared and killed near La Parguera, Puerto Rico, was examined for helminths during postmortem examination. Four microscaphidiids, Angiodictyum mooreae n. sp., A. parallelum, A. anteroporum, and Octangium sagitta; one spirorchiid, Learedius learedi; and one pronocephalid, Cricocephalus rnegastomus, were detected. Angiodictyum mooreae may be distinguished from all known species of Angiodictyum in possessing large prominent marginal bodies. It is most similar to A. parallelum but differs in having a genital pore located immediately posterior to the oral sucker and in having 25–26 marginal bodies on each side. The findings of A. parallelum and A. anteroporum in an Atlantic hawksbill turtle constitute new host records and, for the latter parasite, a new geographic locality record.

ANNUAL MIGRATIONS AND SPAWNING OF COENOBITA CLYPEATUS (HERBST) ON MONA ISLAND (PUERTO RICO) AND NOTES ON INLAND CRUSTACEANS

[Annual migrations and spawning for the common land hermit crab, Coenobita clypeatus in Playa Sardinera and possibly in Uvero, Mona Island, occur in August or early September. Spawning corresponds to the crescent moon in the lunar cycle. Las migraciones anuales y desove del cangrejo ermitano terrestre comun, Coenobita clypeatus en Playa Sardinera y posiblemente en Uvero, Isla de Mona, ocurren en agosto o principios de septiembre. El desove corresponde al cuarto creciente en el ciclo lunar., Annual migrations and spawning for the common land hermit crab, Coenobita clypeatus in Playa Sardinera and possibly in Uvero, Mona Island, occur in August or early September. Spawning corresponds to the crescent moon in the lunar cycle. Las migraciones anuales y desove del cangrejo ermitano terrestre comun, Coenobita clypeatus en Playa Sardinera y posiblemente en Uvero, Isla de Mona, ocurren en agosto o principios de septiembre. El desove corresponde al cuarto creciente en el ciclo lunar.]