Factors linked to temporal and spatial variation in the metazoan parasite communities of green jack Caranx caballus (Günther 1868) (Pisces: Carangidae) from the Pacific coast of Mexico

ABSTRACT

Biotic or abiotic factors responsible for temporal or spatial variation in metazoan parasite communities of the green jack Caranx caballus were studied over a nine-year period using samples collected at locations along the south-central Pacific coast of Mexico. A total of 708 fish were collected from six locations between December 2009 and October 2017. Thirty-two parasite species were identified: three Monogenea, nine Digenea, two Cestoda, five Nematoda, eight Copepoda, and three Isopoda. At the component community level, parasite species richness varied significantly from seven (Zihuatanejo 2016) to 18 (Acapulco Bay 2011). The component communities and infracommunities of C. caballus exhibited a similar pattern: low species numbers, low diversity, and dominance by a single species (mainly the monogenean Pseudomazocraes selene or the digenean Bucephalus varicus). Parasite community structure and species composition varied between locations and/or sampling years. The main factors responsible for these variations were host traits such as feeding behaviour and body size, the occurrence of a set of distinctive parasite species, and possible variations in the availability of infected prey between locations.     

Temporal and seasonal variations in parasites of Metynnis lippincottianus (Characiformes: Characidae), a host from the eastern Amazon (Brazil)

ABSTRACT

This study investigated the influence of temporal and seasonal variation (rainy/dry cycle) on the component community structure and infracommunities of parasites in Metynnis lippincottianus from the eastern Amazon (Brazil). A total of 8,774 parasites representing 9 species and 22,765 parasites representing 12 species was collected in 2011 and 2016 respectively, but only 42.8% of the species were common to both study years. In both years, there was a dominance of Ichthyophthirius multifiliis and the component community was 51% dissimilar. The species richness of parasites and the Berger–Parker dominance were higher in 2016, while the evenness and Brillouin diversity were higher in 2011. The prevalence and abundance of I. multifiliis and P. pillulare, as well as the prevalence of Contracaecum sp. were higher in the rainy season. The abundance of Anacanthorus strongylophalus, Urocleidoides sp., Dadayus pacupeva and Dadaytrema oxycephala was higher in the dry season. Infection with Procamallanus (Spirocamallanus) inopinatus was not influenced by the season, while by Trichodina sp. occurred only in the dry season and Ergasilus xinguensis only in the rainy season. The species richness of parasites, Brillouin diversity index and evenness were higher in the dry season, while the Berger–Parker index was higher in the rainy season. Temporal variation of communities and infracommunities of parasites was influenced by the body size of host populations and increase in anthropogenic impacts. Effect of seasons on environmental quality, host size and availability of infective stages of parasites were the determining factors in structuring the component communities and infracommunities of parasites.     

Gastrointestinal helminth communities of two gekkonid lizard species,Nactus multicarinatus and Nactus pelagicus (Squamata: Gekkonidae), from the Republic of Vanuatu,Oceania

Gastrointestinal helminth communities of two gekkonid species, Nactus multicarinatus and Nactus pelagicus, from the Vanuatu Archipelago were examined. Both helminth communities were depauperate: N. multicarinatus harboured one species of Digenea, Mesocoelium monas, one species of Cestoda, Oochoristica javaensis, four species of Nematoda, Hedruris hanleyae, Parapharyngodon maplestoni, Physocephalus sp. (larvae in cysts), Filarioidea gen. sp. (juvenile); N. pelagicus harboured one species of Cestoda, O. javaensis, four species of Nematoda, H. hanleyae, Falcaustra tannaensis, P. maplestoni, Physocephalus sp. (larvae in cysts). In each helminth community P. maplestoni represented a core species and H. hanleyae was a secondary species. It is postulated that the helminth fauna infecting lizards of the Vanuatu Archipelago originated in Australia and Papua New Guinea and reached the archipelago by rafting; their establishment in Vanuatu was fortuitous.     

Metazoan parasites of Calophysus macropterus (Siluriformes: Pimelodidae) in the Acre and Iaco rivers in the western Amazon region of Brazil: diversity,similarity and seasonal variation

ABSTRACT

The diversity, similarity and seasonal variation of metazoan parasite communities in Calophysus macropterus in the Acre and Iaco rivers, in the western Amazon (Brazil), was investigated. Parasites from 13 taxa were collected from C. macropterus in both rivers: four species of monogeneans, four nematodes, two cestodes, one digenean, one crustacean and one pentastomid. In hosts from the Acre river, Cucullanus pinnai predominated; while in hosts in the Iaco river, Monticellia amazonica predominated. The component communities of the parasites among the hosts in the two rivers presented high similarity (100%). Prevalence of Alinema amazonicum was higher in hosts in the Acre river; while the prevalence of C. pinnai was higher in hosts in the Iaco river and the mean prevalence and abundance of M. amazonica were higher in fish from the Iaco river. Regarding C. macropterus from the Acre river, infection levels by A. amazonicum were higher during the rainy season, while Demidospermus pinirampi only occurred in the dry season and Procamallanus (Spirocamallanus) inopinatus only occurred in the rainy season. In hosts from the Iaco river, infections by larvae of Anisakidae gen. sp. were higher during the dry season, while infection by Rudolphiella piracatinga and Sebekia sp. only occurred in the rainy season. However, P. (S.) inopinatus, Ergasilus callophysus, Ameloblastella unapi, Demidospermus luckyi, Demidospermus macropteri and D. pinirampi only occurred in the dry season. High similarity of the component communities of the parasite was observed between the rainy and dry seasons. These results suggest that factors other than location and seasonality were influencing the communities and infracommunities of the parasites found. Lastly, C. macropterus is a new host for almost 50% of the parasite species found. In addition, the results from the present study have expanded the geographical range of these 13 species of parasites to the western Amazon region.     

Hairworms found in Scottish agricultural land,with descriptions of two new species of Gordionus Muller (Nematomorpha: Gordiidae)

Three species of Nematomorpha were found in a survey of the ground beetles of Scottish agricultural land, Gordionus violaceus (Baird) and two undescribed new species, G. linourgos sp. nov. and G. diligens sp. nov. The morphology of all three species is studied with the aid of SEM, and the characteristics of the cuticle and the male terminal lobes described in detail. All species were found to be parasitic in ground beetles of the family Carabidae, in nine different species (Nebria brevicollis (Fabricius), Harpalus latus (Linnaeus), four species of Pterostichus, and three species of Calathus). Gordionus violaceus is also reported to be a parasite of the spider Arctosa alpigena (Lycosidae). Up to four specimens were found in the same host, typically one adult and several juvenile forms. Parasitized hosts had severe alterations of their reproductive, digestive and secretory systems. The three species of Gordionus were mostly found in grasslands and coniferous forest, most abundantly in June and July.     

Coral reef tanaidacean assemblages along the SW and SE Gulf of Mexico: biodiversity,geographic distribution and community structure

The biodiversity, geographic distribution, and community parameters of the benthic tanaidaceans associated with three coral reefs along the SW and SE Gulf of Mexico were analysed. A total of 15,525 specimens were grouped in 36 species. The highest value of abundance was found in the PNSAV with 6382 tanaidaceans. The PNSAV presented 30 species, the ANPT-L 16 species, and the SABS 17 species. The species with the widest distribution were Pseudonototanais sp., Condrochelia dubia, Leptochelia forresti, Synapseudes sp., Haplopolemius propinquus, Alloleptochelia longimana, and Paradoxapseudes bermudeus. In the Veracruz System Reef, the highest abundance was recorded for Condrochelia dubia and Pseudonototanais sp. The highest value of diversity was obtained in the SABS (3.08 bits/ind in the reef Bajo Diez), and the lowest value was found in the PNSAV (0.07 bits/ind in the reef Isla de Enmedio). The highest value of abundance was found in coral rubble and macroalgae. A significant relationship between depth and specific richness was found in the three reef systems. Using cluster analysis, three groups were found in each system, mainly related to the proximity to the coast and to urban areas. This is one of the first studies to show the specific substrate and attributes of three communities of tanaidaceans along the SE–SW coast of the Gulf of Mexico.     

The influence of habitat features on amphibian distribution in Northeastern Greece

Environmental and isolation variables relating to abundance of breeding amphibians, species richness and community structure at different spatial scales were examined in the Dadia-Lefkimi-Soufli Forest National Park, Evros, Greece. Logistic regression and a generalized linear model were used to relate several habitat characteristics to species occurrence and species richness. The community structure responses to breeding-pond features were examined at four spatial scales using canonical correspondence analysis (CCA). The richest communities live in low-altitude ponds, with stony or clay bottoms, high solar exposure and abundant submerged and floating vegetation. The CCA models were significant (p < 0.005) and revealed the influence of altitude, percentage of field and broadleaf forest coverage, and number of water bodies on amphibian species assemblages at all four spatial scales. There is a specific need for holistic management of amphibians that will consider habitat connectivity, particularly between aquatic and terrestrial habitats, at a larger, more interconnected scale.     

A study on the developmental bionomics of Dineutes indicus Aube (Gyrinidae,Coleoptera)

Australothis volatilis sp. n., the only species of Heliothinae endemic to New Zealand, is described. The larval food plants, Vittadinia spp., are recorded and other biological information is provided. The male and female genitalia, penultimate and final instar larva, pupa, adult, native food plant, and habitat are illustrated.     

Metazoan endoparasites of 18 anuran species from the mesophytic semideciduous Atlantic Forest in southern Brazil

Brazil has the richest anuran biodiversity in the world and many species have not yet been studied for parasites. One hundred and forty frogs belonging to 18 species (Rhinella schneideri, Dendropsophus aff. minutus, Dendropsophus nanus, Hypsiboas albopunctatus, Hypsiboas punctatus, Hypsiboas raniceps, Phyllomedusa tetraploidea, Pseudis platensis, Scinax fuscovarius, Trachycephalus typhonius, Leptodactylus chaquensis, Leptodactylus fuscus, Leptodactylus aff. latrans, Leptodactylus mystacinus, Leptodactylus podicipinus, Physalaemus cuvieri, Physalaemus nattereri and Elachistocleis bicolor) collected in aquatic habitats in forest remnants and surrounding agricultural landscapes in southern Brazil were examined for endoparasites. Twenty-four species of endoparasites were identified among 21 adult and three larval individuals: one species of Monogenea, Polystoma lopezromani; eight species of Digenea, Catadiscus marinholutzi, Catadiscus propinquus, Choledocystus simulans, Gordoderina sp., Neohaematoloechus neivai, Rauschiella lenti, Rauschiella linguatula, Rauschiella repandum; one species of Cestoda, Ophiotaenia sp.; one species of Acanthocephala, Centrorhyncus sp.; 12 species of Nematoda, Aplectana sp., Aplectana travassosi, Cosmocerca podicipinus, Raillietnema sp., Schrankiana formolusa, Falcaustra mascula, Oxyascaris oxyascaris, Ochoterenella digiticauda, Physaloptera sp., Brevimulticecum sp., Rhabdias sp., Parapharyngodon hylidae; and one species of Annelida, Dero (Allodero) lutzi. The endoparasite fauna found is constituted by generalist species. Two new records of occurrence in Brazil and 33 new host records are reported.     

Deep-water amphipods from the Catalan Sea slope (western Mediterranean): Bathymetric distribution,assemblage composition and biological characteristics

Deep-water epibenthic/suprabenthic species of Amphipoda were studied in the Catalan Sea (north-western Mediterranean) at depths from 389 to 1859 m. In four cruises 20 samples were effected during 1991–1992, covering four different seasonal periods (March, April, July and December). A minimum total of 82 species was collected. Ampelisca uncinata and Eusirus leptocarpus were newly recorded as components of the Mediterranean fauna while three other species collected (Bathymedon sp. A, Autonoe sp. and Rhachotropis cf. gracilis) had distinct possibilities to be new species. The Gammaridae Carangoliopsis spinulosa and the Oedicerotidae Synchelidium maculatum were the two main dominant species on the upper slope level (389-506 m). On the middle slope (between 549-601 m), dominance by any few species was not apparent; the Eusiridae Rhachotropis glabra and R. caeca together with Bathymedon acutifrons, Scopelocheirus hopei and Andaniexis mimonectes were the most abundant species. On the lower slope, at depth below 1000 m, R. caeca was the largely dominant species. The highest species richness (S_T) was reported at intermediate depths over the middle slope (63 species), decreasing with depth increase, and being particularly low at 1808–1859 m (19 species). Total amphipod densities were also higher at the upper and middle slope levels (1760.2–2613.9 amphipods/1000 m³) than below 1000 m (376.4–679.2 amphipods/1000 m³). The low swimming coefficients (K_t) of bathyal Gammaridea, ranging between 0 and 0.336, indicate their relationship to the water-sediment interface although interespecific differences in K_t in relation to species size were also reported. Almost all the dominant amphipods had recruits (=smallest juveniles) in two or three of the three seasons sampled (mainly in March and December), and the smallest juveniles were often only abundant in two of these seasons. This indicates that most species had more than one generation per year, probably suggesting bivoltinism, a commonly adopted biological strategy among intertidal, littoral and shallow water amphipods, as the commonest strategy adopted by the mid-bathyal amphipods in our study.     

An investigation into the metazoan parasites of the spiny dogfish (Squalus acanthias L.), off the west coast of Ireland

The present study was undertaken to examine the parasite fauna of spiny dogfish, and to determine seasonal variations in infection rates and faunal composition. A total of 10 metazoan parasite species was recorded, of which four species occurred in the intestine, three species were parasitic on the gills, two species occurred on the skin, and one species parasitized the spiracle. However, a cumulative parasite species richness curve indicated that a larger sample may have yielded additional parasite species. The parasite assemblage consisted of five species of copepods (Eudactylina acanthii Scott, Caligus curtis Müller, Pandarus bicolor Leach, Echthrogaleus coleoptratus (Guerin-Meneville) and Pseudocharopinus bicaudatus (Krøyer)), two species of nematodes (Anisakis simplex Rudolphi and Hysterothylacium aduncum (Rudolphi)), two species of cestodes (Trilocularia gracilis Olssen and Gilguina squali (Fabricius)), and one species of monogenean (Erpocotyle abbreviata (Olssen)). The parasite fauna was found to be similar to that of S. acanthias from the North Sea, and from New Zealand waters. Results obtained during the present study indicate that the infection rates of certain parasite species display seasonal cycles, most species displaying their greatest prevalence in spring and their lowest prevalence in autumn.     

Metazoan parasite fauna of the round goby Neogobius melanostomus Pallas, 1811 (Perciformes: Gobiidae) collected from the Black Sea coast at Sinop,Turkey

Round gobies (Neogobius melanostomus) were collected from a small stream connected to the Black Sea coast of Sinop, Turkey and examined for metazoan parasites. A total of 122 gobies was investigated throughout a 1‐year period. Long‐term investigations can be useful for finding rare parasites and for determining the diversity and seasonality of parasites. Parasite species recovered were a Digenea gen. sp., Pygidiopsis genata, Ascocotyle sp., Gyrodactylus proterorhini, Dichelyne minutus, Hysterothylacium aduncum, Spiroxys sp., Neoechinohynchus rutilii, and Ergasilus sieboldi. Overall infection prevalence (%) and mean intensity values were 97.5% and 78.2±23.1 parasites per infected fish, respectively. Infection prevalence and mean intensity values for each parasite species in relation to season, fish size, and sex were also determined and discussed.     

New species of Baetidae (Ephemeroptera) from the Upper River Sigi,Usambara, Tanzania

Additional species of mayflies are described from the relatively well-studied fauna of the Upper River Sigi in the East Usambara Mountains of Tanzania. They comprise Cheleocloeon sigiense sp. n. and Centroptiloides ornatus sp. n. A species of Afroptiloides, of which only the adult is known, is figured but not named. The composition of the assemblage of genera known as the Bugilliesia complex is critically examined.     

Three new species of Gamasiphis (Acari: Mesostigmata: Ologamasidae) from Brazil,with complementary information about Gamasiphis plenosetosus Karg and a key to the world species of the genus

Gamasiphis Berlese is one of the most diverse genera of Ologamasidae, with 68 described species, corresponding to about 15% of the species of the family. Until now, a single species of this genus was known from Brazil. Gamasiphis salvadori sp. nov., Gamasiphis flechtmanni sp. nov. and Gamasiphis edmilsoni sp. nov. are described based on the morphology of adult females and males collected from litter and soil in Piracicaba, São Paulo State, Brazil. The holotype of Gamasiphis plenosetosus Karg, 1994 was examined, given its close similarity with the latter species, and complementary morphological information about it is provided. A key for the separation of females of the 60 recognizable world species of Gamasiphis is provided.     

A new lycaenid butterfly exclusively associated with the subalpine sclerophyllous oak forests in Taiwan (Lepidoptera,Lycaenidae, Theclinae)

Subalpine sclerophyllous oak forest grows at high elevation in Taiwan, distantly separated from similar forest communities found in western China, Tibet and India. An investigation on bud‐breaking phenology of oaks and associated phytophagous insects in this community revealed an undescribed species of Teratozephyrus lycaenid. This and other oak‐associated insects suggest that the presence of this oak community in Taiwan resulted from a more widely distributed community. The newly discovered Teratozephyrus turned out to be most closely related to T. nuwaii, described from western China, and is described below as T. elatus sp. nov. Two other species of Teratozephyrus also inhabit Taiwan, but both are associated with broad‐leaved oak forests. Of them, T. arisanus is widespread both in China and Taiwan, is morphologically distinct from the other Teratozephyrus species and is exclusively associated with broad‐leaved oaks. The other, T. yugaii, probably gained its broad‐leaved oak association secondarily as no similar species is found in the broad‐leaved oak communities on continental Asia, and it favours cool, higher‐elevation environments even though its host plant ranges into far lower elevations.     

Composition and habitat use of small mammals in old-growth mountain forests

Old-growth mountain forests in the Pyrenees have natural gap dynamics, a well-developed shrub layer and a large amount of dead wood. Small mammal communities in two types of old-growth forests, silver fir and mountain pine, were studied in July and September in 2006 and 2007. Four species were trapped: bank vole (Myodes glareolus), wood mouse (Apodemus sylvaticus), garden dormouse (Eliomys quercinus) and common shrew (Sorex araneus). Bank voles and wood mice were most commonly trapped (78% of all captures). There were no differences in community composition in the two forest types, although the bank vole was more often captured in the silver fir than in the mountain pine forest. Mammals were more frequently captured at trap stations with high shrub cover, high tree regeneration cover and low herbaceous cover. Our results show that forest structure and, to a lesser extent, forest type determine small mammal community structure, and specifically fine-scale occurrence patterns, in these old-growth forests.     

Four new species of Hargicotyle Mamaev, 1972 (Diclidophoridae) parasites on sciaenid fishes from Peru and Chile

Hargicotyle magna sp. nov., Hargicotyle paralonchuri sp. nov., Hargicotyle sciaenae sp. nov., from the gills of the Sciaenids Sciaena fasciata, Paralonchurus peruanus and Sciaena deliciosa, respectively, and Hargicotyle menticirrhi sp. nov. from the gill and mouth of Menticirrhus ophicephalus are described from the northern Chilean and central Peruvian coast. Distinct characteristics of the new species are the distribution of the vitelline follicles; the number and distribution of the testes, the size, shape and number of larval hooks; and the presence of one or two suckers in each clamp.     

Gastrointestinal helminths of seven gekkonid lizard species (Sauria: Gekkonidae) from Oceania

A total of 1240 specimens of seven species of geckos, Gehyra mutilata, Gehyra oceanica, Hemidactylus frenatus, Hemidactylus garnotii, Lepidodactylus lugubris, Lepidodactylus moestus and Lepidodactylus paurolepis, from Oceania were examined for helminths. Two species of Cestoda, Cylindrotaenia allisonae and Oochoristica javaensis, eight species of Nematoda, Hedruris hanleyae, Maxvachonia chabaudi, Parapharyngodon maplestoni, Pharyngodon lepidodactylus, Physalopteroides arnoensis, Skrjabinelazia machidai, Spauligodon gehyrae and Spauligodon hemidactylus and larvae of two nematode species, Ascarops sp. and Physaloptera sp. were found. The mean helminth species richness for infected geckos was 1.1 - 0.3 SD (range=1-3 species). Helminths reported in this study are generalists. Twenty new host records are reported.     

Epibionts and parasites of Macrobrachium rosenbergii and Metapenaeus dobsoni from Gosthani estuary

Juveniles of two species of commercially important prawns, Metapenaeus dobsoni (Miers) and Macrobrachium rosenbergii (De Man) collected from Gosthani estuary, Bheemunipatnam near Visakhapatnam, India during the period August 1995 to August 1996 were subjected to a detailed study with a view to identifying the various species of epibionts and parasites and to monitor the seasonal changes in the occurrence and abundance of common species of ciliates and larval helminths. A wide range of protozoan and metazoan parasite species was encountered in the prawns. The protozoans were represented by epicommensal ciliates belonging to the genera Zoothamnium, Epistylis, Acineta, Vorticella, an unidentified apostome ciliate and two species of gregarines. The metazoan parasites included metacercariae of families Opecoelidae and Microphallidae, a larval cestode, a larval nematode and two species of bopyrid isopods. Altogether eight species were found infecting M. rosenbergii and 11 species infected M. dobsoni. A majority of the parasite species infected both the hosts. The peritrichous and apostome ciliates constituted the dominant members of the parasite fauna, occurring on both species of prawns as epibionts with high prevalence and density. All the other infections were rarely encountered. Infections with gregarines were restricted to M. dobsoni while those of microphallid metacercariae were found only in M. rosenbergii. Zoothamnium infections were more common on M. rosenbergii than on M. dobsoni. Apparent differences in the parasite fauna, attributed to differences in the behaviour of the two species, were noted. Seasonally Zoothamnium infections were at their peak during monsoon and post-monsoon months and these infections appear to be governed directly by salinity of the habitat and indirectly by the rainfall. Apostome ciliate infections were at their peak during the months November and February. Opecoelid metacercarial infections were confined to the period August to February, with peak during summer months.     

The food web of parasitoid wasps and their non-phytophagous fly hosts in birds' nests (Hymenoptera: Chalcidoidea,and Diptera: Cyclorrhapha)

We present a food-web study of the parasitoid wasps and their fly hosts found in the nests of cavity-nesting songbirds. This birds' nest parasitoid web is different from all parasitoid webs studied comprising exclusively non-phytophagous host species. A total of 490 nests were examined for host occurrence, abundance and parasitism rates. Thirty-two species of potential hosts and 10 species of parasitoid wasps were recorded in nests from 25 sites in northern Germany and from two additional sites in south-western Germany. Most of these species were rare and unspecialized. The only very common parasitoid was Nasonia vitripennis (Chalcidoidea: Pteromalidae). The records of 14 regular host species from northern Germany, which are connected to all 10 parasitoid species, were used for further calculation of food-web statistics. The parasitoid communities in birds' nests were compared with other known parasitoid communities. The birds' nests exhibited a lower species richness compared with communities of phytophagous hosts, but showed similarities with communities of necrophagous or coprophagous hosts, or of parasitoid hosts. The parasitism rate was comparable in all host–parasitoid-systems, supporting the idea that the parasitism rate is independent of species richness.