Paul Sikkel

Paul Sikkel
University of Miami | UM · Rosenstiel School of Marine and Atmospheric Science

PhD

About

110
Publications
27,889
Reads
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1,607
Citations
Additional affiliations
November 2014 - present
North-West University
Position
  • Professor
May 2014 - present
Silliman University
Position
  • Professor (Associate)
January 2014 - present
University of the Virgin Islands
Position
  • Professor (Associate)

Publications

Publications (110)
Article
Full-text available
Fish-associated microorganisms are known to be affected by the environment and other external factors, such as microbial transfer between interacting partners. One of the most iconic mutualistic interactions on coral reefs is the cleaning interactions between cleaner fishes and their clients, during which direct physical contact occurs. Here, we ch...
Article
Assessing the importance of intrinsic and extrinsic factors that shape the spatial distribution of genetic diversity of symbionts has been a topic of debate for decades. While host-mediated dispersal is an important driver of gene flow in many terrestrial metazoan symbionts, few studies have identified the drivers of symbiont genetic differentiatio...
Article
Full-text available
The distribution and abundance of organisms is typically shaped by multiple biotic and abiotic processes. Micropredators are parasite-like organisms that are smaller than their hosts and/or prey and feed on multiple hosts during a given life stage. Unlike typical parasites, however, they spend much or most of their time free-living, associating onl...
Conference Paper
Full-text available
The nature of parasite-host interactions on coral reefs and how they are affected by environmental change is poorly understood. Among the parasites whose abundance is most likely affected by changing environmental conditions are monogenean flatworms. One monogenean in particular, Neobenedenia melleni (MacCallum 1927) is an abundant and highly damag...
Preprint
Full-text available
Fish associated microorganisms are known to be affected by the environment and other external factors, such as microbial transfer between interacting partners. One of the most iconic mutualistic interactions on coral reefs are the cleaning interactions between cleanerfishes and their clients, during which direct physical contact occurs. Here, we ch...
Article
Full-text available
Parasites are an integral part of coral reef ecosystems due to their influences on population dynamics, biodiversity, community structure, and food web connectivity. The Phylum Apicomplexa contains ubiquitous animal associates including the causative agents of globally important human diseases such as malaria and cryptosporidiosis. Despite their ub...
Article
Full-text available
Gnathiid isopods, common fish ectoparasites, can affect fish physiology, behaviour and survival. Gnathiid juveniles emerge from the benthos to feed on fish blood. In the Caribbean, gnathiids are positively associated with dead coral and negatively associated with live coral, due to coral predation on gnathiids. However, such interactions were unstu...
Article
Full-text available
Due to their unusual life cycle that includes parasitic larval and free living adult stages, gnathiid isopods are typically overlooked in biodiversity surveys, even those that focus on parasites. While the Philippines sits within the region of highest marine biodiversity in the world, the coral triangle, no gnathiid species have been identified or...
Article
By adopting different methods to the inlet of a zooplankton olfactometer, the current study investigates the effect of the energy of chemical flow on the Gnathiid isopod crustaceans predicted behavior. These are mobile external parasites of fishes that have a significant impact on the health of their hosts. They rely at least in part on olfactory c...
Article
Full-text available
Acanthurids (surgeonfishes) are an abundant and diverse group of herbivorous fishes on coral reefs. While their contribution to trophic linkages and dynamics in coral reef systems has received considerable attention, the role of linkages involving their parasites has not. As both consumers of fish tissue and prey to microcarnivores, external parasi...
Article
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Ecosystem degradation due to anthropogenic activities is the primary issue of our times. Theoretical analyses as well as efforts to restore and manage ecosystems depend on comprehensive metrics of ecosystem function. In the case of complex ecosystems such as tropical coral reefs-especially where monitoring , management, and restoration are importan...
Article
Parasites play significant roles in the function of ecosystems and can make up a large proportion of overall biomass. Yet, fundamental aspects of their ecology are often understudied relative to other organisms. Gnathiid isopods are the primary ectoparasites of fishes in coral reef ecosystems. While some studies have investigated their host-detecti...
Article
Full-text available
Extreme warming events that contribute to mass coral bleaching are occurring with increasing regularity, raising questions about their effect on coral reef ecological interactions. However, the effects of such events on parasite-host interactions are largely ignored. Gnathiid isopods are common, highly mobile, external parasites of coral reef fishe...
Article
Parasites can account for a substantial proportion of the biomass in marine communities. As such, parasites play a significant ecological role in ecosystem functioning via host interactions. Unlike macropredators, such as large piscivores, micropredators rarely cause direct mortality. Rather, micropredators impose an energetic tax, thus significant...
Article
Full-text available
Gnathiid isopods are common crustacean parasites that inhabit all oceans from shorelines to depths of over 3000 m and use chemical cues to find their marine fish hosts. While gnathiids are host-generalists, hosts vary in their susceptibility to infestation. However, the mechanisms that mediate differential susceptibility are unknown. Here we used a...
Article
Full-text available
Damselfishes of the genus Stegastes are some of the most abundant fish inhabiting shallow reef habitats. Although Stegastes play an important role in promoting primary production in reef ecosystems, their territories are known to favor the occurrence of bacterial pathogens. However, no studies so far have examined the microbiome composition of Cari...
Article
The reliance of parasites on their hosts makes host-parasite interactions ideal models for exploring ecological and evolutionary processes. By providing a consistent supply of parasites, in vivo monocultures offer the opportunity to conduct experiments on a scale that is generally not otherwise possible. Gnathiid isopods are common ectoparasites of...
Article
Full-text available
Severe disturbances can substantially alter eco-evolutionary processes and dynamics. While the impacts of catastrophic events on the biophysical attributes of communities are sometimes assessed, their effects on the genetic patterns of species remain poorly understood. To characterize how severe disturbances impact species at the molecular level, w...
Article
Full-text available
Gnathiid isopods are marine ectoparasites that feed on the blood of fishes that have been implicated as vectors of blood parasites, with transmission possibly occurring through biting during their parasitic life-stages, or through ingestion by fishes. However, evidence for their role as vectors is limited, reflecting the small number of research gr...
Article
Full-text available
Organisms with a parasitic lifestyle comprise a high proportion of biodiversity in aquatic and terrestrial environments. However, there is considerable variation in the ways in which they acquire nutrients. Hematophagy is a common consumption strategy utilized by some terrestrial, aquatic, and marine organisms whereby the parasite removes and diges...
Article
Full-text available
Predation on parasites is an important ecological process, but few experimental studies have examined the long-term impacts on the prey. Cleaner fish prey upon large numbers and selectively feed on the larger individuals of the ectoparasitic stage of gnathiid isopods. Removal of cleaner fish Labroides dimidiatus for 1.5–12.5 years negatively affect...
Article
Full-text available
Mass coral bleaching events due to rising seawater temperatures are occurring with increasing frequency and are among the most conspicuous consequences of human-induced climate change. While bleaching events have clear impacts on the corals themselves, the impacts on other organisms and on the overall reef community are more difficult to assess. Th...
Chapter
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Despite that aquatic parasite diversity and abundance likely surpasses that of terrestrial parasites, our understanding of aquatic parasites lags far behind our knowledge of terrestrial parasites. This is undoubtedly attributable to our being terrestrial primates and the associated logistical challenges of studying most aquatic environments. Howeve...
Article
Full-text available
Background Juvenile gnathiid isopods are common ectoparasites of marine fishes. Each of the three juvenile stages briefly attach to a host to obtain a blood meal but spend most of their time living in the substrate, thus making it difficult to determine patterns of host exploitation. Sequencing of host blood meals from wild-caught specimens is a pr...
Article
Full-text available
We greatly appreciate the interest in our paper. We were indeed quite surprised by our observations. We also appreciate the discussion on terminology. We have always struggled with how gnathiid isopods appear to straddle the line between “parasite” as traditionally used and “micropredator” as used to describe organisms such as mosquitoes. Indeed, t...
Article
Full-text available
The transition from a planktonic larval stage to a benthic or demersal juvenile stage, “recruitment”, is a crucial event in the life history of coral reef fishes, and has a strong influence on population size. Predation by piscivorous fishes is thought to be the main determinant of recruitment success, and has received the most attention. However,...
Article
Full-text available
Gnathiid isopods are common external parasites/micropredators that feed on the blood of marine fishes. During the course ofprocessing samples of gnathiid isopods collected from light traps in the central Philippines, we observed a gnathiid attached toand apparently feeding from the abdomen of another gnathiid. Because the abdomens of both gnathiids...
Article
Full-text available
The transition from a planktonic larval stage to a benthic or demersal juvenile stage, “recruitment”, is a crucial event in the life history of coral reef fishes, and has a strong influence on population size. Predation by piscivorous fishes is thought to be the main determinant of recruitment success, and has received the most attention. However,...
Article
Full-text available
The spatial patterns of feces deposition have been well studied in many terrestrial organisms, while few studies have examined these behaviors in marine fishes. Territorial animals tend to feed within their respective territories. Thus, individuals are faced with the decision of defecating within their territory, where they live and feed, or outsid...
Article
Full-text available
Parasites account for over half of the biodiversity on coral reefs, yet their ecological impacts are poorly understood. Cymothoid isopods of the genus Anilocra are large, conspicuous ectoparasites of coral reef fishes. French grunt (Haemulon flavolineatum) and brown chromis (Chromis multilineata) are commonly infected by Anilocra spp. in the Caribb...
Article
Full-text available
Despite being one of the most prevalent forms of consumerism in ecological communities, parasitism has largely been excluded from food-web models. Stable isotope analysis of consumers and their diets has been widely used in the study of food webs for decades. However, the amount of information regarding parasite stable isotope ecology is limited, r...
Article
Full-text available
s The importance of the role that parasites play in ecological communities is becoming increasingly apparent. However much about their impact on hosts and thus populations and communities remains poorly understood. A common observation in wild populations is high variation in levels of parasite infestation among hosts. While high variation could be...
Data
Supplement Table 1 – Summary of prevalence of blood parasite infection in different life history stages among Caribbean damselfish species at seven sites. Maximum Infection = Maximum number of infected cells/500 cells among infected fish. Mean Intensity = Mean number of infected cells per 500 cells among infected fish. Mean Intensity was calculated...
Article
Full-text available
Coral reefs harbor the greatest biodiversity per unit area of any ecosystem on earth. While parasites constitute the majority of this biodiversity, they remain poorly studied due to the cryptic nature of many parasites and the lack of appropriate training among coral reef ecologists. Damselfishes (Pomacentridae) are among the most abundant and dive...
Article
Full-text available
Mutualisms are pivotal in shaping ecological communities. Iconic images of cleaner fish entering the mouths of predatory fish clients to remove ectoparasites epitomize their mutual benefit. Experimental manipulations of cleaner wrasse reveal declines in fish size and growth, and population abundance and diversity of client fishes in the absence of...
Article
Full-text available
Juveniles of the Cape white seabream Diplodus capensis were observed cleaning adult conspecifics in a large tidepool off Sodwana Bay, South Africa. Although nine other tropical fish species were present and interacted with a nearby pair of Labroides cleaner wrasses, only adults of D. capensis posed for and were cleaned by the D. capensis juveniles....
Article
Full-text available
On coral reefs, gnathiid isopods are a common blood-feeding ectoparasite of reef fishes that can have significant impacts on reef-fish health and fitness. Cleaner fishes and shrimps are the only major documented predators of gnathiids, removing them from the bodies of host fishes. However, gnathiids spend most of their lifecycle free living and thu...
Article
Full-text available
Gnathiid isopods are one of the most common fish ectoparasites, and are found in both temperate and tropical oceans. On coral reefs, gnathiids are most active at dusk and dawn, and contribute significantly to trophic dynamics, as they are a prey resource for cleaner fish and parasitize numerous fishes. Gnathiids also inhabit temperate intertidal wa...
Article
Full-text available
Apicomplexan parasites are obligate parasites of many species of vertebrates. To date, there is very limited understanding of these parasites in the most diverse group of vertebrates, actinopterygian fishes. While DNA barcoding targeting the eukaryotic 18S small subunit (SSU) rRNA gene sequence has been useful in identifying apicomplexans in tetrap...
Article
Full-text available
Gnathiid isopods are among the most common ectoparasitic organisms infesting marine fishes in benthic marine environments, and are best known in coral reef ecosystems. These micropredators are ecologically important, as they can impact their hosts directly through blood loss and tissue damage, and indirectly by transmitting blood parasites. Their a...
Article
Full-text available
Tropical Atlantic reef fishes in the family Haemulidae (grunts) remain quiescent on reefs during the day and migrate to seagrass beds or sand flats at night. Hypothesized advantages of such nocturnal migrations are increased food availability and/or decreased predation risk. Here, we tested predictions of an alternative hypothesis that nocturnal mi...
Article
Full-text available
A morphological review and molecular characterization of Anilocra haemuli Bunkley Williams & Williams, 1981, were completed using specimens collected from Haemulon flavolineatum Desmarest, 1823 (French grunt) and Epinephelus guttatus Linnaeus, 1758 (red hind). Molecular and morphological data suggest that the isopods parasitizing H. flavolineatum a...
Data
Kimura 2-Parameter (K2P) distance of Anilocra spp.
Article
Full-text available
Successful invasions are largely explained by some combination of enemy release, where the invader escapes its natural enemies from its native range, and low biotic resistance, where native species in the introduced range fail to control the invader. We examined the extent to which parasites may mediate both release and resistance in the introducti...
Article
Full-text available
Successful invasions are largely explained by some combination of enemy release, where the invader escapes its natural enemies from its native range, and low biotic resistance, where native species in the introduced range fail to control the invader. We examined the extent to which parasites may mediate both release and resistance in the introducti...
Article
Full-text available
Characterizing spatio-temporal variation in the density of organisms in a community is a crucial part of ecological study. However, doing so for small, motile, cryptic species presents multiple challenges, especially where multiple life history stages are involved. Gnathiid isopods are ecologically important marine ectoparasite, micropredators that...
Article
Full-text available
The transition from a planktonic larval stage to a benthic or demersal juvenile stage is a crucial event in the life history of coral reef fishes, and recruitment success has a strong influence on reef-fish population size. Post-settlement predation is thought to limit recruitment success. Most studies on post-settlement predation have focused on p...
Article
Full-text available
Parasitic micro-organisms can influence multiple ecological processes, from growth, mortality, and behavior, to community structure and trophic interactions, yet are typically ignored components of marine biodiversity. We collected 1298 blood samples from reef fishes off 6 eastern Caribbean islands, representing 27 families, 57 genera and 103 speci...
Article
Full-text available
Risk of infection by parasites may be an important contributing cause or consequence of animal movement patterns. The diel movement patterns of French grunt, a common Caribbean coral reef fish, are well documented and known to connect reef and seagrass habitat. In the northeastern Caribbean, French grunts are known to be infected by Anilocra haemul...
Article
Full-text available
Risk of infection by parasites may be an important contributing cause or consequence of animal movement patterns. The diel movement patterns of French grunt, a common Caribbean coral reef fish, are well documented and known to connect reef and seagrass habitat. In the northeastern Caribbean, French grunts are known to be infected by Anilocra haemul...