An environmental assessment of the parasite fauna of the reef-associated grouperEpinephelus areolatusfrom Indonesian waters

Abstract

Sixty Epinephelus areolatus were examined for metazoan fish parasites in Indonesia, off Segara Anakan lagoon, Java and in Balinese waters. The study revealed 21 different parasite species, and 14 new host and locality records. The anisakid nematodes Anisakis typica and, for the first time in Indonesia, Anisakis sp. HC-2005 were identified by using molecular methods. Ecological parameters were calculated for both sites off the anthropogenically influenced Segara Anakan lagoon and the relatively undisturbed reference site at the southern Balinese coast. The fish from Segara Anakan demonstrated a significantly higher enzymatic activity (Hepatosomatic index) and a significantly reduced number of heteroxenous gut helminths (e.g. the digenean Didymodiclinus sp., the nematode Raphidascaris sp. and the acanthocephalan Serrasentis sagittifer). Other regional differences for E. areolatus included ecto-/endoparasite ratio, endoparasite diversity, the parasite species composition and prevalence of infection of the respective parasite species. We applied the stargraph method to visualize observed regional differences using grouper parasites as biological indicators for the sampled coastal ecosystems at both sampling sites.

Parasites of the grouper fishEpinephelus coioides(Serranidae) as potential environmental indicators in Indonesian coastal ecosystems

“…So far, regional differences (Palm & Rü ckert, 2009, Kleinertz et al, 2012; the present study) and long-term annual changes inside a mariculture farm in the Thousand Islands and inside the heavily disturbed 'natural habitat' of Segara Anakan have been found. According to these data, free-living E. coioides had a high parasite load, similar to those of E. fuscoguttatus (Rü ckert et al, 2010) and E. areolatus (Kleinertz et al, 2012). Regular parasitological monitoring of these commercially important fish species will be able to detect environmental conditions and change, possibly serving as an early warning system in Indonesian coastal habitats.…”

“…A comparison with published data from Ringgung, Lampung Bay, Sumatera in 2003 Palm & Rü ckert, 2009) revealed a low endoparasite diversity according to and high ectoparasite/ endoparasite ratio, with 0.85/0.67-1.00 in the lagoon, followed off the coast of Segara Anakan lagoon at Teluk Bay with 1.71; 0.71 and Lampung Bay with 1.84; 0.67. Highest endoparasite diversity according to Shannon-Wiener: 1.86/1.67-2.04 and a low ectoparasite/ endoparasite ratio with 0.73/0.57 -0.88 were recorded for E. coioides off the Balinese coast, a region that was considered of high environmental quality by Kleinertz et al (2012). The cluster analyses and multi-dimensional scaling plots likewise illustrated these differences; however, they are far less sensitive than the applied star graph method (compare fig.…”

“…The diversity of the collected metazoan endoparasite fauna of each fish species was determined by using the Shannon -Wiener diversity index (H 0 ) and, according to Kleinertz et al (2012), the Evenness index (E) of Pielou (Magurran, 1988) and other parameters were tested (see below). Microsporean parasites were not considered because it was not possible to calculate their intensity.…”

“…The Simpson diversity index, Evenness index and hepatosomatic index were added according to Kleinertz et al (2012). In addition, the prevalences of five different parasite species were used to distinguish among the sampling sites: Scolex pleuronectis and Terranova sp.…”

“…By using the star graph method to integrate different fish parasitological parameters into the same figure, Palm & Rü ckert (2009) and Kleinertz et al (2012) visualized regional differences within Indonesian waters, and Palm et al (2011) visualized annual changes. Ten different parameters were chosen to describe the parasite communities of E. coioides at the sampling sites.…”