Melissa Querido Cárdenas

Parasites of native Cichlidae populations and invasive Oreochromis niloticus (Linnaeus, 1758) in tributary of Amazonas River (Brazil)

This study provides the first investigation on acquisition of parasites in invasive O. niloticus by parasite species of native Cichlidae from the Igarapé Fortaleza basin, Northern Brazil. There were examined 576 specimens of 16 species of native cichlids and invasive O. niloticus collected in the main channel and the floodplain area of this tributary of Amazon River. The invasive O. niloticus was poorly parasitized having only Ichthyophthirius multifiliis, Trichodina centrostrigeata, Paratrichodina africana, Trichodina nobilis (Protozoa) and Cichlidogyrus tilapiae (Monogenoidea), and this host has not acquired any parasite species common to the native ichthyofauna region. In contrast, species of native cichlids showed rich fauna of parasites with predominance of Monogenoidea species, larvae and adults of Nematoda, Digenea, Cestoidea and Acanthocephala, besides four species of Protozoa and four Crustacea. However, only T. nobilis was acquired by native fish, the Aequidens tetramerus, which is a new host for this exotic Trichodinidae. In O. niloticus, well established in the region, the small number of helminth species may be associated with its rusticity, good adaptation in the new environment and also the presence of native parasites with relative specificity, but without ability to complete its life cycle in this invasive host of this ecosystem.

First record of Philometra katsuwoni (Nematoda, Philometridae), a parasite of skipjack tuna Katsuwonus pelamis (Perciformes, Scombridae), off South American Atlantic Coast

The nematode Philometra katsuwoni Petter & Baudin-Laurencin, 1986, a gonad-infecting parasite of Katsuwonus pelamis (Linneaus 1758), originally described from the Gulf of Guinea, is reported for the first time from the coastal zone of Rio de Janeiro State, Brazil. As compared with the original description, the males of the Brazilian material are generally somewhat larger and their right spicule and the gubernaculum are longer. The subgravid female is described for the first time. It is characterized by the anterior inflation of the esophagus and by the presence of two distinct caudal lobes.

A new species of Philometra Costa, 1845 (Nematoda: Philometridae) from the freshwater fish (red piranha) Pygocentrus nattereri Kner (Characidae) in Amazonia, Brazil

A new nematode species, Philometra nattereri n. sp. (Philometridae), is described from female specimens found in the oculo-orbits and nasal cavity of the red piranha Pygocentrus nattereri Kner (Characiformes: Characidae) from five lakes in Central Amazonia, Brazil, collected in 2008 and 2009 (overall prevalence 12%, intensity 1–3 nematodes per fish). Based on light and scanning electron microscopical examination, the new species differs from most other congeners parasitising freshwater fishes in that its oesophageal gland extends anteriorly far anterior to the level of the nerve-ring, in the presence of 14 small cephalic papillae arranged in two circles and in having two minute caudal projections. This is the first species of Philometra Costa, 1845 reported from fishes of the family Characidae and the second valid species of this genus parasitic in freshwater fishes of Brazil and South America.

A new species of diplectanid (Monogenoidea) from Paranthias colonus (Perciformes, Serranidae) off Peru

Pseudorhabdosynochus jeanloui n. sp. (Monogenoidea, Diplectanidae) is described from specimens collected from the gills of the Pacific creolefish, Paranthias colonus (Perciformes, Serranidae) from a fish market in Chorrillos, Lima, Peru. The new species is differentiated from other members of the genus by the structure of its sclerotized vagina, which has two spherical chambers of similar diameter. This is the first Pseudorhabdosynochus species described from the Pacific coast of America, the third species of the genus reported from South America and the first described from a member of Paranthias.

Occurrence of Aelurostrongylus abstrusus (Railliet, 1898) larvae (Nematoda: Metastrongylidae) infecting Achatina (Lissachatina) fulica Bowdich, 1822 (Mollusca: Gastropoda) in the Amazon region

Achatina fulica or “giant African snail” is an exotic species, considered to be one of the world’s hundred most invasive species, causing serious environmental damages. In the present study we report, for the first time, the occurrence of Aelurostrongylus abstrusus infecting A. fulica in the Amazon region. This nematode is described parasitizing mainly the pulmonary system of felines, which causes “aelurostrongilose”, also known as feline cardio-pulmonary strongyloidosis. New morphometric data of third stage larvae are presented herein. The present study demonstrated that 40% of all the snails were infected by A. abstrusus. Achatina fulica specimens were collected from three different areas in Manaus namely: rural; east and west areas. The east area presents the highest prevalence of 80%. The large number of A. fulica found in inhabited areas increases the chances of emergent zoonoses, which highlights the need of further studies so as to better control this disease.

A New Species of Choricotyle (Monogenoidea: Diclidophoridae) from Ctenosciaena gracilicirrhus (Teleostei: Sciaenidae), a Marine Fish Occurring in the Littoral Zone from the State of Rio de Janeiro, Brazil

Abstract A new species of Choricotyle parasitizing the marine fish Ctenosciaena gracilicirrhus (Teleostei: Sciaenidae) from Angra dos Reis, Rio de Janeiro, Brazil (23°00′24″S; 44°19′05″W) is proposed. Choricotyle rohdei n.sp. differs from all other species of the genus mainly by the number of genital spines, which varies from 28 to 30, whereas others present 7 to 12 spines.

Seasonality of parasitic helminths of Leporinus macrocephalus and their parasitism rates in farming systems in the Amazon

The objective of the present study was to analyze the seasonality of parasitic helminths of Leporinus macrocephalus from fish farms in the municipality of Cruzeiro do Sul, Acre, Brazil, and their parasitism rates. Between June 2014 and March 2015, 200 specimens were sampled from two fish farms: one with a semi-intensive system and the other with an extensive system (100 fish from each farm: 50 during the dry season and 50 during the rainy season). Fifteen species of parasites were found, with seasonal variations of some according to the farming system. In the semi-intensive fish farm, there was greater prevalence of infection during the dry season. Also, Urocleidoides paradoxus, Procamallanus (Spirocamallanus) inopinatus, Goezia leporini and Rhabdochona (Rhabdochona) acuminata presented differences in their parasitism rates between the seasons. In the extensive fish farm, no variation in the prevalence of infection was observed between the seasons and two species Tereancistrum parvus and G. leporini demonstrated differences only regarding the mean intensity of infection. The data presented here may help fish farmers to understand the parasite dynamics of L. macrocephalus in farming systems during the dry and rainy seasons in the state of Acre.

Metazoan parasite communities of Leporinus macrocephalus (Characiformes: Anostomidae) in cultivation systems in the western Amazon, Brazil

In the Amazon, the growing demand for fish has been boosting the expansion of fish farms. However, the intensification of cultivation can generate disequilibrium in the parasite-host environment, predisposing fish to parasitic infections. The objective of this study was to evaluate the community structure of metazoan parasites in cultivation systems of piaucu, Leporinus macrocephalus, in the state of Acre, Brazil. We examined 100 specimens from a semi-intensive cultivation system (earth tanks) and 100 from an extensive system (dams). Overall 66.5% of the hosts were parasitized. We collected 1,240 parasite specimens, classified in 15 metazoan taxa (10 monogenoidean, one digenean and four nematodes). The parasite prevalence was higher by Monogenoidea in the dams, and by Nematoda in the earth tanks. The parasitic indexes were, in general, low and varied among species. Monogeneoidea had higher values for quantitative and ecological descriptors of parasitism in the dams, while Nematoda had higher values in the earth tanks. A single species of Digenea was found in the dams, with low prevalence. No taxon was classified as central. In the dams, parasite abundance was correlated only with total fish length, while in the earth tanks, it was positively correlated with total length, weight and condition factor of fish. The endoparasite and ectoparasite infracommunities presented higher richness, dominance, diversity and evenness, respectively, in the earth tanks and in the dams. This is the first study of ecological descriptors of parasites of L. macrocephalus in the Amazon.

Helminth parasites of Ctenosciaena gracilicirrhus (Perciformes: Sciaenidae) from the coast of Angra dos Reis, Rio de Janeiro State, Brazil

During a survey of the helminth parasites of Ctenosciaena gracilicirrhus from the Atlantic Ocean, off Angra dos Reis, Rio de Janeiro State, Brazil, 10 species of metazoan parasites were collected: 1 species of Monogenea (Choricotyle rohdei); 3 species of Nematoda (Hysterothylacium sp. third stage larvae, Raphidascaris sp. third stage larvae, and Procamallanus (Spirocamallanus) pereirai third and fourth stages larvae and adults); 6 species of Digenea (Opecoeloides pedicathedrae, Opecoeloides melanopteri, Diplomonorchis leiostomi, Aponurus laguncula, Parahemiurus merus and Manteriella sp.). Choricotyle rohdei and Hysterothylacium sp. had the highest prevalence, mean intensity and abundance and an aggregated pattern of distribution was observed in both species. A positive correlation between the standard length of hosts and the parasitic abundance of Hysterothylacium sp. and C. rohdei was observed. The prevalence of C. rohdei was positively correlated with standard length of the host, while in Hysterothylacium sp. there was no correlation. Ctenosciaena gracilicirrhus represents a new host record to all species of Nematoda and Digenea presented herein. The genus Manteriella is reported for the first time in South America.

Cytochemical Analysis of the Body Wall of the Flounder Parasite Procamallanus (Spirocamallanus) halitrophus (Nematoda: Camallanidae)

Abstract Procamallanus (Spirocamallanus) halitrophus (Fusco and Overstreet, 1978) is an intestinal parasite of the flounders Syacium papillosum and Citharichthys macrops, both of which are native to waters off the coast of the state of Rio de Janeiro, Brazil. With transmission electron microscopy, we observed the body wall which is composed of the cuticle, hypodermis, and somatic musculature. The cuticle of P. (S.) halitrophus is composed of 5 layers: the epicuticle, cortical, median, fibrous, and basal layers. Underlying the cuticle is the hypodermis, a syncytium that contains mitochondria, glycogen granules, vesicles, inclusion bodies, and an endoplasmic reticulum. The region of hypodermal chords contains a nucleus in addition to the other organelles and there is a basal lamina surrounding each muscle cell. The use of imidazole-buffered osmium tetroxide solution revealed the presence of lipids in the epicuticle, the membrane that surrounds each muscle cell, the inclusion bodies, and the endoplasmic reticulum. The phosphotungstic-acid technique revealed basic proteins in the epicuticle and dense bodies. The use of periodic acid-thiosemicarbazide-silver proteinate for carbohydrate detection did not show any reaction products in the cuticle. However, glycogen particles were evident in the hypodermis and muscle cells.