Three new Dactylogyrus species (Monogenea: Dactylogyridae) and redescription of one other, gill parasites of five Labeo spp. (Cypriniformes: Cyprinidae) from the Sanaga basin (Cameroon, Central Africa)

ABSTRACT Three new and one already known species of Dactylogyrus Diesing, 1850 are described from five species of Labeo (Cyprinidae) sampled in the middle section of the Sanaga hydrosystem (Centre Region-Cameroon): Dactylogyrus sanagaensis sp. nov. from Labeo sanagaensis Tshibwabwa, 1997, L. nunensis Pellegrin, 1929, L. camerunensis Trewavas, 1974 and L. annectens Boulenger, 1903; Dactylogyrus nachtigalensis sp. nov. and D. yassensis Musilová, ehulková & Gelnar, 2009 from Labeo batesii Boulenger, 1911; and Dactylogyrus djimensis sp. nov. from Labeo camerunensis. Dactylogyrus sanagaensis sp. nov. is close to D. longiphalloides, D. longiphallus, D. leonis, D. marocanus, and D. dembae, however it can be easily distinguished from these species by the size of MCO. Dactylogyrus nachtigalensis sp. nov. is similar to D. dembae and D. sanagaensis sp. nov. but this new species can be mainly differentiated by the length of penis. Dactylogyrus djimensis sp. nov. mostly similar to D. omega can be differentiated from it by the penis diameter. Dactylogyrus yassensis collected from Cameroon doesnt significantly differ morphometrically from the original description, thus extends the distribution of this species to Sanaga basin. Monogenean species collected from Labeo spp. in the middle section of the Sanaga hydrosystem were classified into two morphological groups: the pseudanchoratus-like group and the cyclocirrus-like group newly defined herein. Phylogenetic relationships are suggested among Dactylogyrus species.

Three new Dactylogyrus species (Monogenea: Dactylogyridae) and redescription of one other, gill parasites of five Labeo spp. (Cypriniformes: Cyprinidae) from the Sanaga basin (Cameroon, Central Africa)

Three new and one already known species of Dactylogyrus Diesing, 1850 are described from five species of Labeo (Cyprinidae) sampled in the middle section of the Sanaga hydrosystem (Centre Region-Cameroon): Dactylogyrus sanagaensis sp. nov. from Labeo sanagaensis Tshibwabwa, 1997, L. nunensis Pellegrin, 1929, L. camerunensis Trewavas, 1974 and L. annectens Boulenger, 1903; Dactylogyrus nachtigalensis sp. nov. and D. yassensis Musilová, Rehulková & Gelnar, 2009 from Labeo batesii Boulenger, 1911; and Dactylogyrus djimensis sp. nov. from Labeo camerunensis. Dactylogyrus sanagaensis sp. nov. is close to D. longiphalloides, D. longiphallus, D. leonis, D. marocanus, and D. dembae, however it can be easily distinguished from these species by the size of MCO. Dactylogyrus nachtigalensis sp. nov. is similar to D. dembae and D. sanagaensis sp. nov. but this new species can be mainly differentiated by the length of penis. Dactylogyrus djimensis sp. nov. mostly similar to D. omega can be differentiated from it by the penis diameter. Dactylogyrus yassensis collected from Cameroon doesn't significantly differ morphometrically from the original description, thus extends the distribution of this species to Sanaga basin. Monogenean species collected from Labeo spp. in the middle section of the Sanaga hydrosystem were classified into two morphological groups: the 'pseudanchoratus-like group' and the 'cyclocirrus-like group' newly defined herein. Phylogenetic relationships are suggested among Dactylogyrus species.

Doenças parasitárias de peixes ornamentais cultivados em Santa Catarina: patógenos e patogenia

O cultivo de organismos aquáticos para fins ornamentais é apreciado e representa um mercado consolidado no mundo. No entanto, situações de confinamento animal constituem sempre um fator que favorece o surgimento de doenças. O presente estudo teve como objetivo relatar a fauna parasitária de peixes ornamentais cultivados em três propriedades no estado de Santa Catarina, bem como observar as possíveis patogenias ocasionadas pelos parasitos. Entre maio de 2015 e fevereiro de 2016 foram coletados ao acaso um total de 781 peixes ornamentais e utilizados para análise parasitológica e histopatológica. Em cada propriedade, a qualidade de água foi medida nos viveiros. Observou-se a presença do protozoário ciliado Ichthyophthirius multifiliis; Trichodina sp.; dos monogenoides Dactylogyrus extensus, D. minutus e Diaphorocleidus kabatai; metacercárias de digenéticos; cestoide Bothriocephalus acheilognathi; nematoide Rhabdochona sp. e o branquiúro Argulus japonicus nos animais examinados. A maior taxa de prevalência (45%) e intensidade média (3,7±2,0) foi observada nas brânquias de Gymnocorymbus ternetzi parasitados por Diaphorocleidus kabatai, seguida pelo protozoário Ichthyophthirius multifiliis parasitando a superfície corporal de Xiphophorus maculatus com prevalência de 40% e intensidade média de 1,0±0,0. A análise histopatológica mostrou hiperplasia epitelial interlamelar e das lamelas secundárias, fusão parcial das lamelas secundárias, telangiectasia, edema justalamelar e infiltrado inflamatório eosinofílico. No intestino observou-se necrose na submucosa intestinal, obstrução intestinal e infiltrado inflamatório linfoeosinofílico. É importante o conhecimento da fauna parasitária de peixes cultivados bem como a patogênese causada pelos parasitos nos hospedeiros para garantir a produção de peixes e a saúde dos hospedeiros

The ornamental fish farming is appreciated and represents a consolidate market over the world. However, situation of confinement constitutes a factor that favors the disease occurrence. This study aimed to report the parasitic fauna of ornamental fish from three facilitiesin the state of Santa Catarina, as well as to observe the possible pathogenesis caused by the parasites. Between May 2015 and February 2016, a total of 781 ornamental fishes were used for parasitological and histopathological analysis. From each facility, the water quality was measured in fish ponds. Ciliated protozoan Ichthyophthirius multifiliis; Trichodina sp.; the monogeneans Dactylogyrus extensus, D. minutus and Diaphorocleidus kabatai; metacercariae of digeneans; cestode Bothriocephalus acheilognathi; nematode Rhabdochona sp. and the branchiuran Argulus japonicus, were found in the examined specimens. The greatest prevalence rate (45%) and mean intensity (3.7±2.0) was observed in the gills of Gymnocorymbus ternetzi parasitized by Diaphorocleidus kabatai, followed by the protozoan parasite Ichthyophthirius multifiliis on the body surface of Xiphophorus maculatus with 40% prevalence and mean intensity 1.0±0.0. Histopathological analysis showed epithelial interlamellar hyperplasia of the secondary lamellae, partial fusion of the secondary lamellae, telangiectasia, justalamelar edema and eosinophilic infiltrate inflammatory. The intestine showed necrosis in the submucosa, intestinal obstruction and lymphoeosinophilic inflammatory infiltrate. It is important to know the parasitic fauna of farmed fish and the pathogenesis caused by the parasites in order to ensure the fish production and health of the hosts

Monogenoidea (Dactylogyridae) em tilápias-do-nilo cultivadas sob diferentes densidades de estocagem em tanques-rede / Monogenoidea (Dactylogyridae) in Nile tilapia cultured under different stocking densities in cages

Avaliaram-se a prevalência e a intensidade de infecção por Monogenoidea em tilápias-do-nilo (Oreochromis niloticus) cultivadas sob diferentes densidades de estocagem em tanques-rede de 4m³. O delineamento experimental foi inteiramente ao acaso, com quatro tratamentos - densidades (D) de D1=250, D2=300, D3=350 e D4=400 peixes/m³, três repetições por tratamento, utilizando-se 360 peixes capturados e analisados no período de fevereiro a junho de 2003. Os parâmetros físico-químicos da água foram mensalmente monitorados. Observaram-se prevalências de 52,8; 62,5; 69,4; 83,3; 58,3 por cento e intensidade média parasitária de 112,8; 65,7; 274,0; 97,8; 100,2 de Dactylogyrus sp. (Monogenoidea: Dactylogyridae). Não houve relação da prevalência e intensidade de infecção com a densidade de cultivo, porém foi verificado efeito quadrático (P<0,05) da intensidade parasitária em função do mês. Verificaram-se maior intensidade média de infecção (274) e elevada prevalência (83,3 por cento) nos meses em que a temperatura e a transparência da água oscilaram abaixo dos limites recomendados para o conforto térmico e bem-estar das tilápias.(AU)

The prevalence and infection intensity of Monogenoidea in Nile tilapia (Oreochromis niloticus) cultivated under different stocking densities in 4m³ cages were evaluated. The experiment was designed in sample random sampling with four treatments - densities (D) of D1=250, D2=300, D3=350, and D4=400 fish/m³- and three repetitions, using 360 fish captured and analyzed during the period from February to June 2003. Physiochemical parameters of the water were monthly monitored. Prevalences of 52.8; 62.5; 69.4; 83.3; and 58.3 percent and parasitic mean intensities of 112.8; 65.7; 274.0; 97.8; and 100.2 Dactylogyrus sp. (Monogenoidea: Dactylogyridae) were observed. No relationship between the prevalence and infection intensity with the cultivation density was found. However, quadratic effect was verified (P<0.05) related to the parasitic intensity in function of the month. High mean intensity of infection (274) and high prevalence (83.3 percent) were verified in the months in that the temperature and the transparency of the water oscillated below the recommended limits for the thermal comfort and well-being of tilapia.(AU)