Naidispora caidianensis n. gen. n. sp. infecting coelomocytes of oligochaete Branchiura sowerbyi (Oligochaeta: Naididae) in China.

A new microsporidian parasite, Naidispora caidianensis n. gen. n. sp. was found in coelomocytes of oligochaete Branchiura sowerbyi Beddard, 1892 from Wuhan city, Hubei Province, China. Opaque, hypertrophied coelomocytes (0.17-0.24 mm in diameter) depicted clinical signs of infection. Electron microscopy revealed a microsporidian with monokaryotic life stages. Rounded uninucleate meronts subsequently transformed into multinucleate merogonial plasmodia with masses of electron-dense projections on their plasma membrane. Electron-dense sporogonial plasmodia separated into uninucleate sporonts through rosette-like budding, and further developed into sporoblasts, enclosed by a sporophorous vesicle. Uninucleate mature spores were pyriform, measured 4.1 ± 0.1 (3.9-4.3) µm × 2.1 ± 0.07 (1.9-2.2) µm (average ± SE, range, n = 50), and contained a mushroom-like anchoring disk, bipartite polaroplast, electron-lucent posterior vacuole, trilaminar spore wall and 12-14 turns of an isofilar polar filament arranged in 2-3 ranks. The 1542 bp sequence from B. soweryi showed the highest similarity (below 80 %) with Nematocenator marisprofundi (accession number: JX463178). SSU rRNA gene-based phylogenetic analysis demonstrated that the novel taxon formed an independent clade from known microsporidian parasites. Based on the ultrastructural features and SSU rRNA gene sequence, we propose the establishment of a novel genus (Naidispora n. gen.) and species (Naidispora caidianensis n. sp.) to contain this parasite.

Two new species of Bacillidium (Microsporidia) from coelomocytes of Branchiura sowerbyi (Oligochaeta: Naididae) in China.

Bacillidium spp. exclusively infect oligochaetes and these microsporidian pathogens are typically characterized by their rod-shaped spores. Seven Bacillidium spp. are presently reported from different organs of oligochaetes. Here, we describe two new Bacillidium species, Bacillidium sinensis n. sp. and Bacillidium branchilis n. sp., from coelomocytes of Branchiura sowerbyi. This is the first report of Bacillidium spp. in oligochaetes from China. Both species of Bacillidium elicit the formations of opaque xenoma-like lesions in coelomocytes of the host. A diplokaryotic nucleus occurs in all life stages of these two new Bacillidium species. Mature spores of B. sinensis are 15.9 ± 0.6 (14.7-17.1) µm long (average ± standard error, range, n = 50) and 2.5 ± 0.1 (2.3-2.7) µm wide in fresh preparations. A new type of exospore (sixteen-layered exospore) is discovered from B. sinensis n. sp. which is distinctly different from B. branchilis n. sp., and other Bacillidium spp. (double-layered exospore) reported previously. These two Bacillidium species are morphologically distinguished from each other and all Bacillidium spp. described previously in terms of hosts, infection sites, spore size, spore wall or polar filament thickness. BLASTn searches indicated that these two new microsporidian parasites are surprisingly most similar to Janacekia tainanus (94.76% for B. sinensis and 90. 2% for B. branchilis) isolated from the fat body of midge larva (Kiefferulus tainanus). Phylogenetic analysis demonstrates that the two novel taxons cluster with J. debaisieuxi, J. tainanus, and Bacillidium sp. within the Jirovecia-Bacillidium-Janacekia clade. Other available 18S rRNA gene sequences for microsporidia that infect oligochaetes include J. sinensis, B. vesiculoformis, Neoflabelliforma aurantiae, and Bacillidium sp., but these do not form a single cluster with B. sinensis and B. branchilis, but are instead dispersed through the clade. Based on the ultrastructural features and molecular characteristics, two new species within the genus Bacillidium, B. sinensis n. sp. and B. branchilis n. sp., are designated.

Transcriptomic analysis of oligochaete immune responses to myxosporeans infection: Branchiura sowerbyi infected with Myxobolus cultus.

The Myxozoa are endoparasites characterized by a two-host life cycle that typically involves invertebrates and vertebrates as definitive and intermediate hosts, respectively. However, little is known about invertebrate-myxosporean interactions, particularly about patterns of host immune defense. We used RNA-sequencing to identify genes that are possibly involved in the immune responses of the oligochaete Branchiura sowerbyi naturally infected with Myxobolus cultus. De novo assembly of the B. sowerbyi transcriptome yielded 119,031 unigenes, with an average length of 896 bp and an N50 length of 1754 bp. Comparative transcriptome analysis revealed 4059 differentially expressed genes (DEGs) between M. cultus-infected and uninfected B. sowerbyi groups, including 3802 upregulated genes and 257 downregulated genes. Among the B. sowerbyi immune factors implicated in the responses to M. cultus infection, DEGs related to lectins, ubiquitin-mediated proteolysis, phagocytosis, oxidative-antioxidative responses, proteases, and protease inhibitors were upregulated. The expression of some immune-related molecules such as calmodulin, heat shock proteins, antimicrobial peptides, lysenin, and serum amyoid A protein were also significantly upregulated. The expression patterns of 14 immune-related DEGs identified by RNA-seq were validated by quantitative real-time polymerase chain reaction. This study is the first attempt to characterize the B. sowerbyi transcriptome and identify immune-related molecules possibly associated with M. cultus infection. It is also the first report of invertebrate host-myxosporean interactions at the transcriptomic level. Our results will facilitate the elucidation of adaptive evolution mechanisms of myxosporean parasites in the definitive host and the genetic basis for differences in resistance of invertebrate hosts of different genotypes to a myxosporean species.

Involvement of aurantiactinomyxon in the life cycle of Thelohanellus testudineus (Cnidaria: Myxosporea) from allogynogenetic gibel carp Carassius auratus gibelio, with morphological, ultrastructural, and molecular analysis.

During the investigation of actinosporean fauna diversity from commercial fish ponds in Hubei Province, China, a novel aurantiactinomyxon type was found from Branchiura sowerbyi. Spore body of the aurantiactinomyxon was ellipsoidal in side view and triangular in apical view, 15.5 ± 0.5 (14.5-16.4) µm in diameter; three leaf-like caudal processes were approximately equal, measuring 13.2 ± 0.9 (11.5-16.2) µm long and 7.4 ± 0.4 (6.7-8.0) µm wide at the base; three polar capsules were located at the apex of spore body, globular in apical view, 2.2 ± 0.1 (2.0-2.3) µm in diameter, and pyriform in side view, 2.5 ± 0.2 (2.3-2.9) µm in length and 2.0 ± 0.2 (1.8-2.4) µm in width; a total of 32 germ cells were observed within the sporoplasm. Ultrastructural analysis showed that the development was asynchronous between pansporocysts but synchronous within a pansporocyst. The formation of sporoblast and the development of sporogonic stage were also described and discussed. The 18S ribosomal DNA sequences of the current aurantiactinomyxon type corresponded to that of a previously reported Thelohanellus testudineus, suggesting that the newly identified aurantiactinomyxon type is the actinosporean stage in the life cycle of T. testudineus.

Mutualistic association of rotifer Philodina roseola with the branchiuran fish ectoparasite Argulus bengalensis at its embryonic stage.

Several rotifers including Philodina spp. are well known to make commensal and parasitic associations with different animals. The present investigation was carried out to decipher the relationship of Philodina roseola with a piscine ectoparasite Argulus bengalensis in its embryonic stage. Mechanical removal of the symbiont P. roseola from the argulid egg strips resulted in the complete (100%) failure in hatching. Several P. roseola individuals were found to feed on the solidified jelly coat of the eggs enabling the larvae to emerge under both laboratory and field conditions. Under the laboratory condition, the experimental removal of P. roseola did not affect the embryonic development, but it rendered the jelly coat intact; therefore, the larvae were unable to make hatching furrow and subsequently died. The results of our experiments thus prove this service-resource relationship to be a mutualism. Although the association is facultative for P. roseola, it is obligatory for Argulus spp. An act of intervention in this relationship thus offers a promising control of argulosis.

The life cycle of Thelohanellus kitauei (Myxozoa: Myxosporea) infecting common carp (Cyprinus carpio) involves aurantiactinomyxon in Branchiura sowerbyi.

Thelohanellus kitauei is a freshwater myxosporean parasite causing intestinal giant cystic disease of common carp. To clarify the life cycle of T. kitauei, we investigated the oligochaete populations in China and Hungary. This study confirms two distinct aurantiactinomyxon morphotypes (Aurantiactinomyxon type 1 and Aurantiactinomyxon type 2) from Branchiura sowerbyi as developmental stages of the life cycle of T. kitauei. The morphological characteristics and DNA sequences of these two types are described here. Based on 18S rDNA sequence analysis, Aurantiactinomyxon type 1 (2048 bp) and Aurantiactinomyxon type 2 (2031 bp) share 99.2-99.4 %, 99.8-100 % similarity to the published sequences of T. kitauei, respectively. The 18S rDNA sequences of these two aurantiactinomyxon morphotypes share 99.4 % similarity, suggesting intraspecific variation within the taxon, possibly due to geographic origin. Phylogenetic analyses demonstrate the two aurantiactinomyxon types clustered with T. kitauei. Regardless, based on 18S rDNA synonymy, it is likely that Aurantiactinomyxon type 1 and 2 are conspecific with T. kitauei. This is the fourth elucidated two-host life cycle of Thelohanellus species and the first record of T. kitauei in Europe.

Ornamental fish mortality reveals an old parasite introduction: A case study of Koi carp and fish louse.

Koi carp are globally known for their colors and cultural significance. The introduction of these fish to new environments poses a threat to local biodiversity, in addition to releasing parasites, such as argulid ectoparasites. This study presents a record of Argulus japonicus infecting carp in an artificial lake in Southern Brazil using morphological and molecular methods, with a 100% prevalence (n = 3) and a mean intensity of 21.6 parasites per host, distributed over the body surface. The invasion history of hosts in the study locality indicates that the introduction of A. japonicus occurred decades before its first formal record in Brazil.

Jirovecia branchilis n. sp. (Microsporidia) from glands of Branchiura sowerbyi (Oligochaeta: Tubificidae) in China.

Jirovecia species primarily infect oligochaetes and are typically characterized by large rod-shaped spores with a tail-like posterior prolongation. Presently, seven Jirovecia spp. are reported worldwide with only one described in China. Here, a new species, Jirovecia branchilis n. sp. was discovered in glands of oligochaetes Branchiura sowerybi Beddard, 1892 in China. Jirovecia branchilis n. sp. elicited the formation of numerous opaque xenomas of 0.12 to 0.20 mm (n = 30) in diameter. Electron microscopic observations demonstrated that the earliest developmental stages observed were uninucleate meronts residing directly with the host cytoplasm. Mature spores were rod-shaped with blunt ends and possessed a collar-like anchoring disk, a manubrium-type polar filament, a bipartite polarplast, and a three-layered spore wall. A tail-like prolongation was distinctly observed in the posterior of spores and measured 13.2-28.6 µm long (n = 30). Jirovecia branchilis n. sp. showed 98.54% sequence similarity with Janacekia tainunus isolated from the fat body of chironomidae larvae Kiefferulus tainanus based on obtained partial SSU rDNA gene sequence, but was significantly different in morphology, host, and infection sites. SSU rDNA-based phylogenetic analysis indicated Jirovecia branchilis n. sp. clustered with Janacekia tainanus within the Jirovecia-Bacillidium-Janacekia clade. In conclusion, a new species within Jirovecia, Jirovecia branchilis n. sp. is erected herein based mainly on its morphological, ecological, and to a lesser degree on its molecular characteristics. The whole relationship between Jirovecia spp., Janacekia spp., and Bacillidium spp. is in need of revision and could potentially be elucidated by using additional makers and sequencing a broader diversity of the already described species.

Behavioral and physiological toxicity thresholds of a freshwater vertebrate (Heteropneustes fossilis) and invertebrate (Branchiura sowerbyi), exposed to zinc oxide nanoparticles (nZnO): A General Unified Threshold model of Survival (GUTS).

The toxic effects of Zinc oxide nanoparticles (nZnO) on Branchiura sowerbyi and Heteropneustes fossilis, was assessed in a 96-hour acute exposure regime using behavioral (including loss-of balance and clumping tendencies) and physiological (mucus secretion and oxygen consumption) endpoints. While the relationship between behavioral, physiological biomarkers, and exposure concentrations was assessed using correlation analysis, nZnO toxicity was further predicted using the General Unified Threshold model for Survival (GUTS). The time-dependent lethal limits for acute nZnO toxicity (LC50) on B. sowerbyi were estimated to be 0.668, 0.588, 0.448, and 0.400 mg/l, respectively, at 24, 48, 72, and 96 h whereas for H. fossilis the LC50 values are 0.954, 0.905, 0.874 and 0.838 mg/l. Threshold effect values i.e., LOEC (Lowest Observed Effect Concentration), NOEC (No Observed Effect Concentration), and MATC (Maximum Acceptable Toxicant Concentration) threshold effect values at 96 h were higher for fish compared to the oligochaete. For B. sowerbyi, the GUTS-SD (stochastic death) model is a better predictor of nanoparticle exposure effects compared to the GUTS-IT (individual tolerance) model, however in the case of H. fossilis, the reverse pattern was observed. Oxygen consumption rate was negatively correlated to mortality under acute exposure duration. The strong negative correlation between mortality and oxygen consumption strongly suggests a metabolic-toxicity pathway for nZnO exposure effects. The higher toxicity threshold values i.e., LOEC, NOEC, and MATC for fish compared to the oligochaete invertebrate indicates greater risks for invertebrates compared to vertebrates, with resultant implications for local habitat trophic relationships.

Description of life stages, molecular characterisation as well as a new host and locality record of Chonopeltis lisikili Van As and Van As (1996) from Phongolo River, South Africa.

Chonopeltis lisikili Van As and Van As, 1996 was original described from the Eastern Caprivi (Namibia) and the Okavango System (Botswana), collected from five Synodontis Cuvier, 1816 (Mochokidae) species. This fish genus is endemic to Africa, with 130 valid species, making it one of the most species-rich and widely distributed mochokid catfish family. During parasitological surveys conducted in the Phongolo River (South Africa), a Chonopeltis Thiele, 1900 species was collected from Synodontis zambezensis Peters, 1852. In total, 21 adult females, four adult males, as well as representatives of the larval developmental stages were found. After morphological comparison, this branchiuran was identified as C. lisikili. This paper provides additional information on body measurements and morphological information of all the life stages of the Phongolo material. Information on Chonopeltis material collected from the Okavango River, Botswana, not yet published is also included as well as the first molecular characterisation of a Chonopeltis species using COI and 18 S rRNA partial sequencing. The endemicity of the host and fish lice necessitates a discussion on the host origin and distribution in more than one river system, particularly referring to host specificity for Chonopeltis species.

Identification of proteins from the secretory/excretory products (SEPs) of the branchiuran ectoparasite Argulus foliaceus (Linnaeus, 1758) reveals unique secreted proteins amongst haematophagous ecdysozoa.

BACKGROUND: It is hypothesised that being a blood-feeding ectoparasite, Argulus foliaceus (Linnaeus, 1758), uses similar mechanisms for digestion and host immune evasion to those used by other haematophagous ecdysozoa, including caligid copepods (e.g. sea louse). We recently described and characterised glands associated with the feeding appendages of A. foliaceus using histological techniques. The work described in the present study is the first undertaken with the objective of identifying and partially characterising the components secreted from these glands using a proteomic approach. METHODS: Argulus foliaceus parasites were sampled from the skin of rainbow trout (Oncorhynchus mykiss), from Loch Fad on the Isle of Bute, Scotland, UK. The proteins from A. foliaceus secretory/excretory products (SEPs) were collected from the supernatant of artificial freshwater conditioned with active adult parasites (n = 5-9 per ml; n = 560 total). Proteins within the SEPs were identified and characterised using LC-ESI-MS/MS analysis. Data are available via ProteomeXchange with identifier PXD016226. RESULTS: Data mining of a protein database translated from an A. foliaceus dataset using ProteinScape allowed identification of 27 predicted protein sequences from the A. foliaceus SEPs, each protein matching the criteria of 2 peptides with at least 4 contiguous amino acids. Nine proteins had no matching sequence through OmicsBox (Blast2GO) analysis searches suggesting that Argulus spp. may additionally have unique proteins present in their SEPs. SignalP 5.0 software, identified 13 proteins with a signal sequence suggestive of signal peptides and supportive of secreted proteins being identified. Notably, the functional characteristics of identified A. foliaceus proteins/domains have also been described from the salivary glands and saliva of other blood-feeding arthropods such as ticks. Identified proteins included: transporters, peroxidases, metalloproteases, proteases and serine protease inhibitors which are known to play roles in parasite immune evasion/induction (e.g. astacin), immunomodulation (e.g. serpin) and digestion (e.g. trypsin). CONCLUSIONS: To our knowledge, the present study represents the first proteomic analysis undertaken for SEPs from any branchiuran fish louse. Here we reveal possible functional roles of A. foliaceus SEPs in digestion and immunomodulation, with a number of protein families shared with other haematophagous ectoparasites. A number of apparently unique secreted proteins were identified compared to other haematophagous ecdysozoa.

Records of new localities and hosts for crustacean parasites in fish from the eastern Amazon in northern Brazil.

The aim of this study was to investigate parasites crustacean fauna in Arapaima gigas, Cichla monoculus, Cichla ocellaris, Cichla jariina, Satanoperca jurupari, Leporinus friderici, Leporinus fasciatus, Hoplias malabaricus, Phractocephalus hemioliopterus, Serrasalmus altispinis, Pseudoplatystoma tigrinum and Potamotrygon motoro of the State Amapá and Pará, in northern Brazil. A total of 242 parasites, including Argulus elongatus, Argulus multicolor,Argulus juparanaensis, Argulus nattereri, Dolops discoidalis, Dolops longicauda, Braga patagonica, Braga fluviatilis, Livoneca guianensis and undetermined Lernaeidae, were collected from these hosts. The Argulus species had the greatest richness among the community of parasitic crustaceans. There was a low abundance of parasites among the hosts, other than D. discoidalis, was most abundant in the integument of A. gigas and P. tigrinum. Finally, the present study reported nine new hosts for the crustacean parasite species and expanded knowledge of the occurrence of some parasite species in the Jari River basin, in eastern Amazon.

Identification and characterisation of hemocyanin of the fish louse Argulus (Crustacea: Branchiura).

Hemocyanin transports oxygen in the hemolymph of many arthropod species. Within the crustaceans, this copper-containing protein was thought to be restricted to Malacostraca, while other crustacean classes were assumed to employ hemoglobin or lack any respiratory protein. Only recently it has become evident that hemocyanins also occur in Remipedia and Ostracoda. Here we report for the first time the identification and characterisation of hemocyanin in the fish louse Argulus, which belongs to the class of Branchiura. This finding indicates that hemocyanin was the principal oxygen carrier in the stem lineage of the pancrustaceans, but has been lost independently multiple times in crustacean taxa. We obtained the full-length cDNA sequences of two hemocyanin subunits of Argulus foliaceus by a combination of RT-PCR, RACE and Illumina sequencing of the transcriptome. In addition, one full-length and one partial cDNA sequence were derived from the transcriptome data of Argulus siamensis. Western blot analysis confirmed the presence of at least two hemocyanin subunits in A. foliaceus, which are expressed at the mRNA level at a 1:3.5 ratio. The addition to the branchiuran hemocyanin subunits to a multiple sequence alignment of arthropod, hemocyanins improved the phylogenetic resolution within the pancrustacean hemocyanins. Malacostracan, ostracod and branchiuran hemocyanins are distinct from the hexapod and remipede hemocyanins, reinforcing the hypothesis of a close relationship of Remipedia and Hexapoda. Notably, the ostracod hemocyanins are paraphyletic with respect to the branchiuran hemocyanins, indicating ancient divergence and differential loss of distinct subunit types.

Flooding modifies the genotoxic effects of pollution on a worm, a mussel and two fish species from the Sava River.

Extreme hydrological events, such as water scarcity and flooding, can modify the effect of other stressors present in aquatic environment, which could result in the significant changes in the ecosystem functioning. Presence and interaction of various stressors (genotoxic pollutants) in the environment can influence the integrity of DNA molecules in aquatic organisms which can be negatively reflected on the individual, population and community levels. Therefore, in this study we have investigated the impact of flooding, in terms of genotoxicity, on organisms belonging to different trophic levels. The study was carried out on the site situated in the lower stretch of the Sava River which faced devastating effects of severe flooding in May 2014. The flooding occurred during our field experiment and this event provided a unique opportunity to assess its influence to the environment. The in situ effects of this specific situation were monitored by measuring physical, chemical and microbiological parameters of water, and by comparing the level of DNA damage in coelomocytes and haemocytes of freshwater worms Branchiura sowerbyi, haemocytes of freshwater mussels Unio tumidus and blood cells of freshwater fish Abramis bjoerkna/Abramis sapa, by means of the comet assay. Our study indicated that the flooding had a significant impact on water quality by decreasing the amount and discharge rate of urban wastewaters but simultaneously introducing contaminants from the nearby fly ash disposal field into river by runoff, which had diverse effects on the level of DNA damage in the studied organisms. This indicates that the assessment of genotoxic pollution in situ is strongly affected by the choice of the bioindicator organism.

Morphological characterization of testicular cells, spermatogenesis and formation of spermatophores in a fish ectoparasite Argulus bengalensis Ramakrishna, 1951 (Crustacea: Branchiura).

The present study has been carried out to describe the cell morphology of the developing male gametes in a fish ectoparasite, Argulus bengalensis Ramakrishna, 1951. With respect to cell volume and nucleoplasmic index, spermatogonia are the smallest and primary spermatocytes are the largest in this lineage. The spermatogonia and the differentiating spermatogenic cells are in separate niches and confined to different enclaves within each testicular lobe. Spermiogenesis occurs within the inner enclave of each testicular lobe. During this process the nucleus becomes streamlined; an acrosome is formed, axoneme is originated, and residual cytoplasm is discarded through the flagellum. The sperm cell morphology displays a general pattern comprising head, mid-piece, and a full length flagellum. In the axoneme 9+2 arrangement of the microtubule is conserved. In addition to the axoneme, some more singlet microtubules are found surrounding a fiber sheath and around one of the mitochondria adjacent to the axoneme. This arrangement indicates a close phylogenetic relationship with pentastomida. In the present study, structure and formation of spermatophore are described in this branchiuran parasite.

Changes in hematological and biochemical parameters of tambaqui (Colossoma macropomum ) parasitized by metazoan species / Alterações nos parâmetros hematológicos e bioquímicos de tambaqui (Colossoma macropomum) parasitado por espécies de metazoários

Abstract The aim of this study was to evaluate the impacts of metazoan parasites on hematological and biochemical parameters and relative condition factor of tambaqui (Colossoma macropomum ) farmed in northern Brazil. A total of 32 juvenile fish were captured from a commercial fish farm located in the municipality of Rio Preto da Eva, Amazonas state, Brazil. Parasite prevalence was 100% for Anacanthorus spathulatus, Mymarothecium boegeri and Notozothecium janauachensis, 100% for Neoechinorhynchus buttnerae and 53.13% for Dolops geayi. The greatest mean parasite intensity was found in acantocephalans followed by monogeneans and branchiuran crustaceans. A negative correlation was observed between abundance of N. buttnerae and hematocrit percentage, hemoglobin concentration, total thrombocyte count and glucose and between abundance of the monogenean and glucose concentration. Parasitic infections caused damage in tambaqui in terms of the observed hematological parameters that were characterized by hypochromic anemia and thrombocytopenia, which are important parameters to be used in parasitic diagnosis. This study is the first record of the occurrence of Dolops geayi in farmed tambaqui in the Amazon.

Resumo O objetivo deste estudo foi avaliar o impacto do parasitismo por metazoários sobre os parâmetros hematológicos, bioquímicos e fator de condição relativo de tambaquis (Colossoma macropomum) cultivados na região Norte do Brasil. Foram coletados 32 tambaquis em fase de engorda numa piscicultura comercial no município de Rio Preto da Eva, estado do Amazonas, Brasil. A prevalência de parasitos foi de 100% para Anacanthorus spathulatus, Mymarothecium boegeri e Notozothecium janauachensis, 100% para Neoechinorhynchus buttnerae e 53,13% para Dolops geayi. A maior intensidade média foi de acantocéfalos, seguida por monogenéticos e branquiúros. Correlação negativa significativa foi observada entre abundância de N. buttnerae e os parâmetros de hematócrito, concentração de hemoglobina, trombócitos totais e glicose, bem como entre a abundância de monogenéticos e glicose. A infecção por parasitos metazoários foi capaz de debilitar os tambaquis como observado por meio das alterações hematológicas; sendo este quadro de anemia hipocrômica e trombocitopenia importante para ser utilizado no diagnóstico destas parasitoses. Este estudo foi o primeiro registro da ocorrência de Dolops geayi em tambaquis cultivados na Amazônia.

Distribution pattern of crustacean ectoparasites of freshwater fish from Brazil / Padrão de distribuição de crustáceos ectoparasitos de peixes de água doce do Brasil

The purpose of this study was to use the informations relating to parasite crustaceans species that was published over the course of one century (1913 to 2013), in order to search for infestation and distribution patterns among these ectoparasites in Brazilian freshwater fish species. This search was carried out on 445 samples of 119 host fish of 27 families within the orders Characiformes, Perciformes, Clupeiformes, Mugiliformes, Osteoglossiformes, Symbranchiformes, Tetraodontiformes and Siluriformes from various regions of Brazil. We organized different host-parasite systems into matrices grouping species at different taxonomic and infestation levels and according to host parameters. Five families of parasites (Ergasilidae, Argulidae, Lernaeidae, Lernaeopodidae and Cymothoidae) distributed into 76 species of 27 genera were analyzed in the host samples, which presented dominance of Ergasilidae species, mainly from the genus Ergasilus. Some crustaceans are host and site-specific, especially in relation to fish in particular habitats and lifestyles (e.g. Perulernaea gamitanae, Anphira branchialis and Riggia paranensis), while other parasites frequently have no preference (e.g. Lernaea cyprinacea and Braga patagonica). We found broadly similar distribution patterns for some crustacean species among the different localities, whereas other species showed well-defined geographical patterns, and these findings were discussed.

O objetivo deste estudo foi utilizar as informações relacionadas com espécies de crustáceos parasitas, que foram publicados durante um século (1913 a 2013), para procurar padrões de infestação e distribuição desses ectoparasitos em espécies de peixes de água doce do Brasil. Esta pesquisa foi realizada em 445 amostras de 119 peixes hospedeiros de 27 famílias de Characiformes, Perciformes, Clupeiformes, Mugiliformes, Osteoglossiiformes, Symbranchiformes, Tetraodontiformes e Siluriformes das diversas regiões do Brasil. Foram organizados em matrizes de agrupamento diferentes sistemas parasito-hospedeiros em diferentes níveis taxonômicos, níveis de infestação e parâmetros dos hospedeiros. Cinco famílias (Ergasilidae, Argulidae, Lernaeidae, Lernaeopodidae e Cymothoidae) de parasitos, distribuídos em 76 espécies de 27 gêneros, foram analisados em amostras dos hospedeiros, que apresentaram dominância de espécies Ergasilidae principalmente do gênero Ergasilus. Alguns crustáceos são hospedeiros e sítios-específicos no hospedeiro, especialmente peixes de determinados hábitat e estilo de vida (por exemplo, Perulernaea gamitanae, Anphira branchialis e Riggia paranensis), enquanto outros parasitos não têm qualquer preferência (por exemplo, Lernaea cyprinacea e Braga patagonica). Foram encontrados padrões muito semelhantes na distribuição de algumas espécies de crustáceos entre as diferentes localidades, enquanto outras espécies mostraram um padrão geográfico bem definido, o que foi discutido aqui.

Argulus chicomendesi sp. n. (Crustacea: Argulidae) parasita de peixes da Amazônia brasileira

A new species of Branchiura is described from Brazil. The specimens were collected from the fishes of the Brazil Amazon. The new species is characterised by: coloration; form and design of dorsal surface carapace, thorax and abdomen; spines in all external margin and ventral surface of abdomen (pleon); ornamentations of the antennae, antennules, legs, ventral surface of the body; form and pigmentation of accessory copulatory structures from the male.

Uma nova espécie de Branchiura é descrita para o Brasil. Os espécimens foram coletados parasitando peixes da Amazônia brasileira. A nova espécie é caracterizada pela: coloração e desenhos da superfície dorsal da carapaça, tórax e abdômen; presença de espinhos em toda a margem externa da superfície ventral do abdômen (pléon); ornamentações das antenas, antênulas, maxilas, pernas, superfície ventral do corpo; forma e pigmentação das estruturas copulatórias acessórias do macho.