parasites

Abstract: The recent rise in ocean temperatures, accompanied by other environmental changes, has notably
increased the occurrence and spread of diseases in Octocorallia, of which many species are integral to shallow
tropical and subtropical coral reef ecosystems. This study focuses on the understanding of these diseases, which
has been largely limited to symptomatic descriptions, with clear etiological factors identified in only a fraction
of cases. A key example is the multifocal purple spots syndrome (MPSS) affecting the common Caribbean
octocoral sea fan Gorgonia ventalina, linked to the gall-forming copepods of the genus Sphaerippe, a member of
the widespread family Lamippidae. The specialized nature of these copepods as endoparasites in octocorals
suggests the potential for the discovery of similar diseases across this host spectrum. Our investigation
employed four molecular markers to study disease hotspots in Saint Eustatius, Curaçao, northwest and
southwest Cuba, and Bonaire. This led to the discovery of a group of copepod species in these varied Caribbean
locations. Importantly, these species are morphologically indistinguishable through traditional methods,
challenging established taxonomic approaches. The observed diversity of symbionts, despite the host species'
genetic uniformity, is likely due to variations in larval dispersal mechanisms. Our phylogenetic analyses
confirmed that the Lamippidae copepods belong to the order Poecilostomatoida (Copepoda) and revealed their
sister group relationship with the Anchimolgidae, Rhynchomolgidae, and Xarifiidae clades, known for their
symbiotic relationships with scleractinian corals. These results add to our understanding of the evolutionary
and ecological interactions of copepods and their hosts, and the diseases they cause, important data in a
changing climate.

Coral reefs harbour an immense diversity of species, many of which live in association with one or more host organisms. Stony corals (Scleractinia) have been documented to host nearly 900 organisms, of which > 310 are decapod crustaceans. This associated fauna is also involuntary host to a diverse parasite fauna. Coral-dwelling gall crabs (Cryptochiridae) are obligate symbionts of scleractinian corals; however, records of their parasites are scarce, with only two named epicaridean isopod species known. Fieldwork focused on cryptochirids in the Indo-West Pacific and Caribbean yielded diverse new collections of both hosts and parasites. This new material was compared with material deposited in museum collections. Both previously described species were encountered in the newly collected material, as well as a new genus and species of bopyrid, a new genus and species of cryptoniscoid, four new species of Danalia, and the first record of a rhizocephalan parasitizing a gall crab, which is also described as a new species. Parasitism of gall crabs is more widespread than what could be assumed based on literature records, and all parasite species appear to be specific to hosts in this crab family. This is the first review of hypersymbioses between stony corals, gall crabs and the crabs' parasites and hyperparasites

Invasive species have a history of damaging their invaded ecosystems and in the case of the Pterois volitans invasion to the waters of many Caribbean Island nations, there has been no exception. Pterois volitans has caused negative impacts to the coal reef ecosystems such as reduced juvenile coral reef fish recruitment and, consequently damage to the associated fisheries. Management strategies of multiple nations are currently centered upon the reduction of populations via hunting. This strategy requires substantial effort and thus long term management solutions may include biotic controls. Parasitism is an important facet of population dynamics and could be important to the population dynamics for Pterois volitans around Bonaire. Pterois volitans is rarely a victim of parasitism in its native range and has similarly low rates of parasitism reported in its invasive range. The prevalence or lack of parasitic interactions between Pterois volitans and native parasites could be important in planning management strategies and controlling populations in the future. This study examined 200 Pterois volitans captured in the coastal waters of Bonaire for parasites in the mouth and gill structure, as well as over the entirety of the skin, to investigate possible interactions occurring between local parasites and Pterois volitans. Only one of the 200 investigated specimens was found to have an isopod attached to its gill structure.

This student research was retrieved from Physis: Journal of Marine Science IX (Spring 2011)19: 44-49 from CIEE Bonaire.

Coral reef ecosystems provide a number of important ecological services, such as nurseries and protection from storms. This makes their health of vital importance for human populations. Past epidemics in the Caribbean involving high mortality of predominant species, such as long-spined sea urchins (Diadema antillarum) and elkhorn coral (Acropora palmata) have shown the potential of disease to fatally disrupt coral reef ecosystems already under stress. The high prevalence of an unknown disease in ocean surgeonfish (Acanthurus tractus) in the Caribbean, and its apparent ability to infect other fish, including parrotfish and other predominant grazers, is a source of concern since it affects a number of herbivorous fish that are integral to the health of the reefs. This disease is identified by the presence of black spots over the body and fins of infected fish. The number of spots can vary widely. Fin rot and lethargic behavior have been noted in fish with large numbers of spots. Bacterial cultures of swabs from healthy and dark spot epidermis, and necropsy of eight A. tractus specimens were used to attempt to identify the causative agent. This study found smaller bacterial numbers in the dark spot epidermis compared to healthy epidermis cultures, and the presence of encysting organisms embedded in the epidermis directly below black spots in body and fins of A. tractus. Additional encysting organisms were found deeper in the muscle tissue and did not produce a black spot. These encysting organisms are proposed to be digenean trematodes in the metacercariae life stage.

This student research was retrieved from Physis: Journal of Marine Science XIV (Fall 2013)19: 103-109 from CIEE Bonaire.

Bonaire’s coral reefs remain among the healthiest in the Caribbean. Although the island’s reefs have suffered bleaching disturbances similar to those plaguing reefs throughout the Caribbean, they uniquely show signs of recovery. Here we highlight key findings from our March 2015 biennial coral reef monitoring expedition. We put the findings in the context of both the trends recorded since 2003 when we began our regular monitoring and the most recent research related to the factors controlling the structure and functioning of healthy coral reef ecosystems. 

In the past, diseases and infections have had dramatic impacts on Caribbean coral reef ecosystems (e.g. white band disease in corals (Pantos and Bythell, 2006); mass mortality of the sea urchin Diadema (Lessions, 2005)). Regular monitoring of reef organisms for signs of disease and infections may be important as an “early warning system” to possibly prevent devastating outbreaks. 
In September 2013 an unusual number of reef fish species (e.g. Scaridae (Fig. 1.1 , Acanthuridae and Pomacanthidae) infected with dermal parasites were observed during a dive at Salt Pier (M. de Graaf, pers. obs.). In September 2014 one princess parrotfish infected with dermal parasites was dissected and internal and external samples were send to the Central Veterinairy Institute (CVO) in Lelystad (Netherlands) for further histopathological examination. According to CVO the parrotfish suffered from a microspore parasitic infection of the skin, muscles and digestive tract. The cysts caused fibrotic abscesses and necrosis on the fins.

Similar dermal parasites were observed in a recent survey of coral reef fishes on Curaçao and the observed external blemishes were associated with infections by trematodes (digenean metacercaria), turbellarians and protozoans (Cryptocaryon) (Bernal et al., 2015). Bernal et al. (2015) reported that infection rates of coral reef fish on Curacao were almost ten times higher compared to infection rates of coral reef fish surveyed in Mexico and Belize. To date, only anecdotal observations exist of parasite infections on coral reef fish on Bonaire but no quantitative assessment of the prevalence of dermal parasites is available. 
The objective of the Helpdeskvraag was to:
1) conduct a “quick scan” to determine the current prevalence of dermal parasites among the coral reef fish of Bonaire, and

2) advise EZ on possible consequences and future actions depending on the outcome of the “quick scan”.