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At least 145 records · Page 8Linked to original sources
PubMed2001

A new species of Acusicola Cressey (Copepoda: Ergasilidae) from northeastern Brazil.

A new species of Acusicola is described based on adults of both sexes taken from plankton samples collected in the upper reaches of the Piauí River estuary, in the northeast of Brazil. Ovigerous females were present in the plankton. The new species, Acusicola minuta n. sp., can be distinguished from its congeners by its small body size, female antennal morphology and leg setation. The male described here as A. minuta n. sp. is the first known male attributed to the genus.

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PubMed2001

Resurrection of Perissopus galeorhini (Yamaguti, 1936), with notes on the genus Perissopus Steenstrup & Lütken, 1861 (Copepoda: Pandaridae) parasitic on sharks.

Recently collected copepod parasites on the narrownose smooth-hound shark Mustelus schmitti Springer revealed enough similarities with Perissopus galeorhini (Yamaguti, 1936) to be considered conspecific. Comparison of these specimens with the types of P. oblongus (Wilson, 1908) showed that P. galeorhini and P. oblongus are distinct species. Therefore, P. galeorhini is considered a valid species rather than a synonym of P. oblongus, as it has been treated since the revision of Cressey (1967). Descriptions of P. galeorhini from M. schmitti and type-material of P. oblongus are provided along with a discussion on their taxonomic status. P. galeorhini differs from P. oblongus in features relating to the anterior margin of cephalothorax, the dorsal plates of the third pedigerous segment and details of the segmentation and armature of the appendages. In addition, an amended diagnosis of Perissopus Steenstrup & and Lütken, 1861 is given, including characters not previously considered by Cressey (1967) such as: the dorsal plate of segment 2 can be small, widely separated, covered by the posterior end of the lateral processes of the cephalothorax and not always extending to the posterior border of the plates of segment 3; and the rami of legs 3 can be 2-segmented.

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PubMed2001

The mesoparasitic genera of the Ergasilidae (Copepoda): with descriptions of new species of Paeonodes Wilson and Therodamas Krøyer.

One species of each of the three mesoparasitic ergasilid genera, Therodamas Krøyer, Mugilicola Tripathi and Paeonodes Wilson, is described in detail. The descriptions of P. subviridis n. sp. and Mugilicola bulbosus Tripathi are based on new material collected from Liza subviridis (Valenciennes) from Guam and India, respectively. The description of Therodamas frontalis n. sp. is based on material from Mugil cephalus L. in Brazil and the redescription of Therodamas serrani Krøyer is based on examination of syntype material. The geographical distributions of all three genera are summarised. Analysis of the phylogenetic relationships between species of these three genera indicates that Paeonodes and Mugilicola form a single clade and that Paeonodes, as currently constituted, is paraphyletic.

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PubMed2002

New species and new records of Ergasilus Nordmann (Copepoda: Ergasilidae) from the gills of grey mullet (Mugilidae).

Four new Ergasilus species are described from five host species of grey mullet, family Mugilidae, held in the fish collections of The Natural History Museum, London. Ergasilus extensus n. sp. was found on Myxus petardi (Castelnau) from Australia, E. sittangenesis n. sp. on Sicamugil hamiltoni (Day) from Burma, E. piriformis n. sp. on Sicamugil cascasia (Hamilton Buchanan) from India, and E. ecuadorensis n. sp. on Mugil curema Valenciennes and M. hospes Jordan & Culver from Ecuador. New records of E. cyanopictus Caravalho, E. magnicornis Yin, E. orientalis Yamaguti and E. rostralis Ho, Jayarajian & Radhakrishnan on grey mullet are also given.

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PubMed2002

Redescription of the fish parasite Lernanthropus polynemi Richiardi, 1881 (Copepoda: Siphonostomatoida) and relegation of two congeners to synonymy.

Lernanthropus polynemi Richiardi, 1881 is described, for the first time since its original discovery, based on the type-material found in the Museum für Naturkunde in Berlin, Germany. Morphological features of this parasite, which infects the commercially-caught fish Eleutheronema tetradactylum (Shaw), are described and illustrated, including those of the male, which is described for the first time. The types of another species from the same host, L. lappaceus Wilson, 1912, and deposited in the National Museum of Natural History in Washington DC, are also examined based on the type-specimens. The types of a third congener, L. trifoliatus Basset-Smith, 1898, also from the same host, are not available, but the original illustrations are studied. It is considered that the three nominal species described from E. tetradactylum represent a single taxon, and that L. lappaceus and L. trifoliatus be relegated to synonymy with L. polynemi.

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PubMedDate not supplied

Study of Caligus minimus (Otto, 1821), (Caligidae Copepoda) infections of the sea Bass Dicentrarchus labrax (L.) in Bardawil lagoon.

Caligus minimus (Otto, 1821) is a common parasite of Dicentrarchus labrax in Bardawil Lagoon and it also occurs sporadically on D. punctatus in this lagoon. It has also been found on D. labrax which were recently established in the Gulf of Suez. The incidence as well as the intensity of infection showed a distinct pattern of seasonal variation with maximum levels during winter and early spring and lowest levels of infection during summer and early autumn. Overall infection levels also showed distinct annual variation. Occurrence of larval stages on the fish followed the seasonal pattern observed in infections by adults copepods. The highest occurrence was observed every year in May. However, at any month of the year ovigerous females, and at least a few copeptides or chalimi may be found. Spatial distribution of infection among the fish was significantly contagious and with some exceptions followed the Poisson log normal distribution. However, the magnitude of overdispersion showed distinct seasonal fluctuations, with more extreme overdispersion in summer and autumn. These fluctuations apparently resulted from the diversity of temperature and salinity conditions in the lagoon which were most extreme during the summer and autumn. Positive correlation between host size and infection was evident only in the winter and spring months with highest levels of infection in the largest fish. Female copepods usually out number male copepods. The dominance of female over males was also evident in the preadult stages.

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PubMed1986

Thersitina gasterostei (Pagenstecher, 1861) (Copepoda: Ergasilidae) infecting the stickleback Pungitius pungitius L. at Chalk Marshes, Gravesend, Kent.

10-spined sticklebacks, Pungitius pungitius, taken from a drainage dyke at Chalk Marshes, Kent, between October 1979 and July 1980 were infested with adult females of the parasitic copepod Thersitina gasterostei. Relative density of the overwintering parasite population fell during the winter months to a minimum in April; however during this winter period the proportion of ovigerous females rose, reaching 100% in April. Young infective adults were first seen in May, and the peak of infection by the first summer generation occurred in June. The parasite was found to be overdispersed within the host population: in 8 of 10 monthly samples the negative binomial distribution was a good model for the observed data. Relative density was related to host length in only 3 of the 10 samples. Evidence is presented to suggest that infected fish are more likely than non-infected fish to recruit young parasite.

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PubMed1982

[Oogenesis in Centropages typicus (Copepoda, Calanoida)].

We carried out a complete study of oogenesis in Centropages typicus using structural, ultrastructural and cytochemical data. The usual stages of oogenesis, i.e. germinative phase, premeiosis, primary and secondary vitellogenesis, were found. The latter two stages were the most typical. Primary vitellogenesis consisted of endogenous yolk accumulations; these substances, probably of lipoprotein or lipoglycoprotein nature, were produced at the granular endoplasmic reticulum level and then stocked in the reticulum cavities. During secondary vitellogenesis, endogenous yolk production continued, but we mainly observed the development of exogenous yolk accumulation (lipid droplets and protein globules) in the ooplasm. These accumulations resulted from the fusion of very numerous pinocytotic vesicles arising from the oolemma and containing substances probably brought to the oocytes by the hemolymph. The effect of various proteases on the vitellus globules caused a more or less marked digestion of their contents, tending to prove their protein nature. The end of vitellogenesis was marked by the appearance of vacuolar formations with dense lamellae which could correspond to cortical granules.

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PubMed1989

Natural control of larval Anopheles albimanus (Diptera: Culicidae) by the predator Mesocyclops (Copepoda: Cyclopoida).

Forty-two ground water sites on the Pacific and Atlantic coasts of Colombia were sampled quantitatively with a plankton net to assess the abundance of mosquito larvae and associated fauna. Many of the sites contained substantial numbers of Anopheles albimanus Wiedemann larvae, but the larvae were virtually absent wherever there were large populations of the copepods Mesocyclops venezolanus, M. longisetus, or M. aspericornis. Mesocyclops were observed to prey readily upon first-instar An. albimanus larvae in the laboratory, but smaller genera of cyclopoid copepods did not kill An. albimanus larvae. We conclude that Mesocyclops may prove useful for biological control of Anopheles.

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PubMed1992

Release of Mesocyclops aspericornis (Copepoda) for control of larval Aedes polynesiensis (Diptera: Culicidae) in land crab burrows on an atoll of French Polynesia.

On Tereia Island, Rangiroa Atoll, 14,321 land crab burrows were treated with the copepod Mesocyclops aspericornis from January to June 1986, to control larvae of Aedes polynesiensis marks. In October 1987, the entire island of Tereia was retreated (17,300 burrows), and the neighboring island, Voisin, was left untreated as a control. From 5 to 15 mo after treatment, burrows with M. aspericornis contained an average of 2 Ae. polynesiensis immatures compared with 97 immatures from untreated burrows. Long-term larval control was successful in low-lying areas where burrows remained wet or were reflooded. Although there may have been other contributing factors, the major reason for lack of persistence of M. aspericornis in burrows over the entire island appeared to be poor resistance to desiccation. From all treated burrows in October 1987, M. aspericornis subsequently was found in 89.5, 39.1, and 24.1% of burrows sampled 5, 8, and 15 mo after treatment, respectively. The broad-scale results for Tereia indicated that there was no reduction of adult biting indices when compared with Voisin. Mark-release experiments on four occasions indicated that Ae. polynesiensis had a limited flight range and that the probability for interisland movement was low.

Aedes↗
PubMed1992

Laboratory evaluation of Brazilian Mesocyclops (Copepoda: Cyclopidae) for mosquito control.

In laboratory tests, four different strains of Mesocyclops aspericornis (Daday) collected in or near Fortaleza, Brazil, showed potential as biological control agents of Aedes aegypti (L.) mosquito larvae but were not as effective against Anopheles or Culex. In contrast, the larger M. longisetus (Thiebaud), collected at Fortaleza, killed 100% of Ae. aegypti and Anopheles farauti (Laveran) (No. 1) at larval densities of 200/liter and Culex quinquefasciatus (Say) at 25/liter. In cage simulations with Ae. aegypti and Mesocyclops, both copepod species eliminated all immatures in earthenware pots by week 3. Owing to the lack of replacement, all Ae. aegypti adults subsequently died by week 8 or 9. Although both M. longisetus and M. aspericornis showed maximum reproductive potential at 25 degrees C, breeding occurred from 20 to 35 degrees C. Based on these laboratory evaluations, M. longisetus has been selected for field trials in rural villages in Ceará to control Ae. aegypti.

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PubMed1992

Laboratory evaluation of Acanthocyclops vernalis and Diacyclops bicuspidatus thomasi (Copepoda: Cyclopidae) as predators of Aedes canadensis and Ae. stimulans (Diptera: Culicidae).

Predatory effectiveness of two vernal-pool copepods, Acanthocyclops vernalis (Fischer) and Diacyclops bicuspidatus thomasi (Forbes), was assessed against cohabiting larvae of Aedes canadensis (Theobold) and Aedes stimulans (Walker) in laboratory bioassays. D. b. thomasi did not exhibit predatory behavior toward first instars, even when both organisms were confined in 35-mm wells for 7 d and alternative food sources were not available. A. vernalis did feed on early instars, but its effectiveness was significantly influenced by the presence of alternate food, the size of the container, and the size and age of the larval prey. Results strongly suggest that in a comparatively unrestricted natural vernal-pool habitat where an abundance of other food sources are available, neither copepod species plays a major role in reducing larval mosquito populations.

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PubMed1998

Field evaluation of Mesocyclops longisetus (Copepoda: Cyclopoidea) for the control of larval Aedes aegypti (Diptera Culicidae) in northeastern Mexico.

Field trials of the predacious copepod Mesocyclops longisetus Thiubaud were conducted in northeastern Mexico to determine the effectiveness of this species to control larval Aedes aegypti (L.) populations and to survive and reproduce in nature. Groups of 200, 50, and 50 ovigerous M. longisetus females were inoculated into 200-liter metal drums, discarded tires, and cemetery flower vases, respectively, which are 3 of the more important Aedes breeding sites in this area. Larvae were sampled at 15-d intervals, and total surviving cyclops were collected at the end of the study, 120 d later. Community participation was solicited through a simple training program on copepod rescue before drum cleaning and facilitated by the addition of a drum marker to remind residents of copepod presence. Results showed good cooperation and after 4 mo all peridomestic drums, still supported variable numbers of cyclopoids. Average of larvae reduction was 37.5% for drums, 67.5% for flower vases, and 40.9% for tires. This study shows difficulties of using cyclopoids for tires and vases in areas where prolonged dry seasons desiccated these habitats and reduced copepod survival.

Aedes↗
PubMedDate not supplied

Life cycle and description of Amblyospora camposi n. sp. (Microsporidia: Amblyosporidae) in the mosquito Culex renatoi (Diptera, Culicidae) and the copepod Paracyclops fimbriatus fimbriatus (Copepoda, Cyclopidae).

The life cycle of Amblyospora camposi n. sp. is described from the mosquito Culex renatoi and the copepod Paracyclops fimbriatus fimbriatus collected in the leaf axils of the plant Eryngium cabrerae in Argentina. Meiospores of A. camposi (5.8 x 4.1 microm) were infectious per os to female adults of the copepod P. f. fimbriatus. All developmental stages in the copepod had unpaired nuclei, with sporulation involving the formation of a sub-persistent, sporontogenic, interfacial envelope and the production of a second type of uninucleate spore. These spores, formed in the ovaries of P. f. fimbriatus, were large, pyriform, and measured 10.70 x 3.85 microm. When ingested they infected C. renatoi larvae to initiate a sequence that involves schizogony and gametogony and ends with plasmogamy and nuclear association to form diplokaryotic meronts. Oblong ovate binucleate spores (7.86 x 2.96 microm) are formed in the adult mosquito and are responsible for vertical transmission to the filial generation. This is the first report of an Amblyospora species from a mosquito that inhabits the small-water bodies held in parts of terresterial plants (phytotelmata).

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PubMedDate not supplied

Life cycle, ultrastructure and molecular phylogeny of Hyalinocysta chapmani (Microsporidia: Thelohaniidae), a parasite of Culiseta melanura (Diptera: Culicidae) and Orthocyclops modestus (Copepoda: Cyclopidae).

The complete life cycle of the microsporidium Hyalinocysta chapmani is described from the primary mosquito host Culiseta melanura and the intermediate copepod host Orthocyclops modestus. Infections are initiated in larval C. melanura following the oral ingestion of uninucleate spores from infected copepods. Spores germinate within the lumen of the midgut and directly invade fat body tissue where all development occurs. Uninucleated schizonts undergo binary division (schizogony) followed by karyokinesis (nuclear division) to form diplokaryotic meronts. Merogony is by synchronous binary division. The onset of sporogony is characterized by the simultaneous secretion of a sporophorous vesicle and meiotic division of the diplokaryon resulting in the formation of eight ovoid meiospores enclosed within a sporophorous vesicle. Most infected larvae die during the fourth stadium and there is no evidence of a developmental sequence leading to vertical transmission. Hyalinocysta chapmani is horizontally transmitted to O. modestus via oral ingestion of meiospores. Infections become established within ovarian tissue of females and all parasite development is haplophasic. Uninucleate schizonts divide by binary division during an initial schizogonic cycle. Newly formed uninucleate cells produce a thin sporophorous vesicle and undergo repeated nuclear division during sporogony to produce a rosette-shaped, multinucleated sporogonial plasmodium with up to 18 nuclei. This is followed by cytoplasmic cleavage, sporogenesis, and disintegration of the sporophorous vesicle to form membrane-free uninucleate spores. Infected females eventually die and there is no egg development. The small subunit rDNA sequence of H. chapmani isolated from meiospores from C. melanura was identical to the small subunit rDNA sequence obtained from spores from O. modestus, corroborating the laboratory transmission studies and confirming the intermediary role of O. modestus in the life cycle. Phylogenetic analysis was conducted with closely related microsporidia from mosquitoes. Hyalinocysta chapmani did not cluster within described Amblyospora species and can be considered a sister group, warranting separate genus status.

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