RESUMO
Metazoan parasite communities can experience temporal structural changes related to seasonal and/or local variations in several biotic and abiotic environmental factors. However, few studies have addressed this issue in tropical regions, where changes in water temperature are less extreme than in temperate regions, so the factors or processes that can generate variations in these parasite communities are as yet unclear. We quantified and analysed the parasite communities of 421 Lutjanus peru (Nichols & Murphy, 1922) collected from Acapulco Bay in Guerrero, Mexico, over a four-year period (August 2018 to April 2021), to identify any interannual variation due to local biotic and abiotic factors influenced by natural oceanographic phenomena, such as El Niño-Southern Oscillation, or La Niña. Twenty-five metazoan parasite taxa were recovered and identified: seven Digenea species; two Monogenea; one Cestoda; one Acanthocephala; four Nematoda; and ten of Crustacea (seven Copepoda and three Isopoda). The digeneans and copepods were the best represented parasite groups. The parasite communities were characterized by a high numerical dominance of helminth larvae. Species richness at the component community level (13 to 19 species) was similar to reported richness in other Lutjanus spp. The parasite communities of L. peru had a high variability in species composition, but low aggregate variability (e.g. species diversity), suggesting that structure of these communities may be quite stable over time. A clear interannual variation pattern was not observed, suggesting that parasite species of this host may respond differently to variations in environmental factors. Interannual variations were possibly caused by a combination of biotic (i.e. host feeding behaviour and body size) and local abiotic factors (influenced by climatic anomalies) which generated notable changes in the infection levels of several component species.
Assuntos
Copépodes , Doenças dos Peixes , Parasitos , Perciformes , Trematódeos , Animais , Doenças dos Peixes/parasitologia , Peixes , Perciformes/parasitologia , PeruRESUMO
A new species of Theletrum is described from the intestine of two palenose morays, Echidna nocturna, collected in Cuajiniquil, Guanacaste Province, Costa Rica. The new species differs from the type species, T. fustiforme Linton, 1910 by having a subspherical pars prostatica, a subspherical seminal vesicle extending anteriorly to the anterior border of the acetabulum, by the presence of a poorly developed hermaphroditic sac, and by having a larger body size. We also report eight additional species of digeneans parasitizing marine fishes in several localities along the Atlantic and Pacific coast of Costa Rica: Bianium simonei, Didymozoinae (metacercariae), Ectenurus virgulus, Hypocreadium myohelicatum, Lecithochirium microstomum, Pseudolecithaster sp., Stephanostomum casum, and Tergestia laticollis. In addition, we present an updated list of helminth parasites of marine fish from Costa Rica and discuss the importance of including parasites as an integral part of biodiversity inventories.
Assuntos
Peixes/parasitologia , Tachyglossidae/parasitologia , Trematódeos/isolamento & purificação , Animais , Costa Rica , EcossistemaRESUMO
A new species and genus of Acanthocephala is described based on specimens found in the intestine of Anisotremus interruptus (Gill, 1862), Haemulon sexfasciatum Gill, 1863, Haemulon scudderi Gill, 1863, Pomadasys leuciscus (Günther, 1864), and Eugerres sp. Jordan and Evermann, 1927, from the marine waters of Chamela Bay, Jalisco, México. Koronacantha mexicana n. sp. is characterized by having an elongate proboscis with a heavy cuticle, cuticular body spines, and 8 cement glands, indicating that it should be assigned to the Illiosentidae Golvan, 1960. The genus Koronacantha n. gen. can be distinguished from other members of the family by the possession of (1) a row of heavy, strongly recurved proboscis hooks in the shape of an inverted apostrophe with roots that are simple but exaggerated in size and a small hook blade, occurring just anterior to a posteriormost comblike group of 4 or 5 small, close-set hooks, (2) cerebral ganglion near middle of proboscis receptacle, and (3) paired sensory papillae at mid-neck.
Assuntos
Acantocéfalos/anatomia & histologia , Acantocéfalos/classificação , Doenças dos Peixes/parasitologia , Helmintíase Animal , Enteropatias Parasitárias/veterinária , Animais , Feminino , Peixes , Helmintíase/parasitologia , Enteropatias Parasitárias/parasitologia , Intestinos/parasitologia , Masculino , México , Água do Mar , Caracteres SexuaisRESUMO
A new species of Acanthobothrium in Dasyatis longus from Chamela Bay, Jalisco, Mexico, is a member of a presumed clade of species diagnosed by being anapolytic or nearly so, having more than 100 testes per proglottis, with immature and mature proglottides wider than long to square, aspinose scolex, muscular bothridia fused to the scolex at their posterior ends, H- to V -shaped ovaries, relatively short symmetrical to asymmetrical ovarian arms that extend anteriorly to, or nearly to, the cirrus sac, and vitellaria arranged in fields rather than a single row of follicles. The new species most closely resembles Acanthobothrium terezae from the freshwater stingray Potamotrygon motoro in the following characters: bothridial hooks longer than 200 microns with inner hooks having bent asymmetrical prongs, an average of 130-140 testes per proglottis, and shallow genital atria located posterior to midline of proglottis. The new species differs from A. terezae by having outer hooks approximately the same size and shape as the inner hooks, inner hooks averaging 230 microns rather than 313 microns in total length, and cirrus sacs averaging 255 microns rather than 450 microns in length. The new species is unique among all described species of Acanthobothrium by having a cleft in the posterior margin of each apical bothridial pad. The apparent close relationship of the new species to one inhabiting a Neotropical freshwater stingray provides support for the hypothesized Pacific marine ancestry of Neotropical freshwater stingrays and raises the possibility that the Neotropical freshwater stingrays may not be monophyletic.
Assuntos
Cestoides/classificação , Infecções por Cestoides/veterinária , Doenças dos Peixes/parasitologia , Rajidae/parasitologia , Animais , Cestoides/ultraestrutura , Infecções por Cestoides/parasitologia , México , Microscopia Eletrônica de VarreduraRESUMO
Five new species of Acanthobothrium are described in stingrays from the Gulf of Nicoya, Costa Rica. Acanthobothrium costarricense n. sp. in Dasyatis longus, most similar to Acanthobothrium lilium, Acanthobothrium lineatum, and Acanthobothrium himanturi, has bothridial hooks averaging 125 microns (lateral) and 145 microns (medial) long, an average of 47 testes per proglottis, cirrus sacs averaging 187 microns long, and asymmetrical ovarian lobes with poral lobes reaching the posterior margin of the cirrus sac, and aporal lobes reaching the middle of the cirrus sac. Acanthobothrium cimari n. sp. in D. longus, most similar to A. lilium, A. lineatum, A. himanturi, A. costarricense, and Acanthobothrium semnovesiculum, has bothridial hooks averaging 117 microns (lateral) and 121 microns (medial) long, an average of 50 testes per proglottis, cirrus sacs averaging 164 microns long, and asymmetrical ovarian lobes with poral lobes reaching the posterior margin of the cirrus sac, and aporal lobes reaching the level of the vagina. Acanthobothrium puntarenasense n. sp. in D. longus, distinctive in having a very small scolex relative to the width of the cephalic peduncle similar to Acanthobothrium microcephalum, has bothridial hooks averaging 111 microns (lateral) and 117 microns (medial) long, an average of 50 testes per proglottis, cirrus sacs averaging 170 microns long, and asymmetrical ovarian lobes with poral lobes reaching the posterior margin of the cirrus sac, and aporal lobes reaching the middle of the cirrus sac. Acanthobothrium vargosi in D. longus, most similar to Acanthobothrium brevissime, Acanthobothrium tasajerasi, Acanthobothrium urotrygoni, and Acanthobothrium campbelli, has bothridial hooks averaging 130 microns (lateral) and 133 microns (medial) long, an average of 25 testes per proglottis arranged in 2 single rows, cirrus sacs averaging 91 microns long, and asymmetrical ovarian lobes with poral lobes reaching the posterior margin of the cirrus sac, and aporal lobes reaching the middle of the cirrus sac. Acanthobothrium campbelli n. sp. in Urotrygon chilensis, most similar to a A. brevissime, A. Vargasi, A. lineatum, A. himanturi, and A. urotrygoni, has bothridial hooks averaging 108 microns (lateral) and 111 microns (medial) long, an average of 19 tester per proglottis arranged in 2 nearly linear rows, cirrus sacs averaging 74 microns long, and asymmetrical ovarian lobes with the poral lobe reaching the posterior margin of the cirrus sac, and the aporal lobes reaching the middle of the cirrus sac.