First record of larvae of Hysterothylacium (Nematoda: Anisakidae) with zoonotic potential in the pirarucu Arapaima gigas (Osteichthyes: Arapaimidae) from South America.

Third-stage larvae (L3) of Hysterothylacium sp. were collected by the first time in juveniles of pirarucu Arapaima gigas farmed in the Rio Preto da Eva, Amazonas state. Ninety-eight (98) out of 100 examined fish showed to be parasitized. Five hundred and ninety larvae of Hysterothylacium sp. were collected from the intestines, stomach and pyloric caeca. The mean intensity of parasite indexes was 6.02 (±5.75) ranging from 1 to 40 larvae per host and the mean abundance was 5.9 (±5.76). The A. gigas is the new host record for larvae of Hysterothylacium sp. in Brazil, and this is the first record of larvae of Hysterothylacium (Nematoda: Anisakidae) with zoonotic potential in the pirarucu from South America.

First record of larvae of Hysterothylacium (Nematoda: Anisakidae) with zoonotic potential in the pirarucu Arapaima gigas (Osteichthyes: Arapaimidae) from South America / Primeiro registro de larvas de Hysterothylacium sp.(Nematoda: Anisakidae) com potencial zoonótico em pirarucu Arapaima gigas (Osteichthyes: Arapaimidae) na América do Sul

Abstract Third-stage larvae (L3) of Hysterothylacium sp. were collected by the first time in juveniles of pirarucu Arapaima gigas farmed in the Rio Preto da Eva, Amazonas state. Ninety-eight (98) out of 100 examined fish showed to be parasitized. Five hundred and ninety larvae of Hysterothylacium sp. were collected from the intestines, stomach and pyloric caeca. The mean intensity of parasite indexes was 6.02 (±5.75) ranging from 1 to 40 larvae per host and the mean abundance was 5.9 (±5.76). The A. gigas is the new host record for larvae of Hysterothylacium sp. in Brazil, and this is the first record of larvae of Hysterothylacium (Nematoda: Anisakidae) with zoonotic potential in the pirarucu from South America.

Resumo Larvas de terceiro estágio (L3) de Hysterothylacium sp. foram coletadas pela primeira vez em juvenis de pirarucu Arapaima gigas cultivados no Rio Preto da Eva, Estado do Amazonas. Noventa e oito (98) dos 100 peixes examinados estavam parasitados. Quinhentos e noventa larvas de Hysterothylaciumsp.foram coletados no intestino, estômago e cecos pilóricos. O índice parasitário de intensidade média foi de 6,02 (±5,75) variando de 1 a 40 larvas por hospedeiro e o de abundância média foi de 5,9 (±5,76). A. Gigas é um novo registro de hospedeiro para larvas de Hysterothylacium sp. no Brasil, também sendo, o primeiro registro de larvas de Hysterothylacium sp. com potencial zoonótico em pirarucu da América do Sul.

Parasite fauna monitoring of matrinxã Brycon amazonicus (Spix & Agassiz, 1829) raised in an intensive husbandry system in a stream channel in the state of Amazonas, Brazil

The matrinxã, Brycon amazonicus, is one of the main species being used for aquaculture and fishery activities in the Amazonian region, yet little is known about the parasites that cause its diseases. The present study monitored parasite fauna infesting an intensive husbandry system in a stream channel. The collections were carried out monthly from September, 1997 to January, 1998. Water quality parameters, fish removal procedures, as well as biometry and anaesthetic data were observed in order to monitor the management conditions. Of the 80 sampled fish, 71 (89 percent) were infested with four Monogenoidea species (Anacanthorus spiralocirrus, Jainus amazonensis, Tereancistrum kerri and Trinibaculum brazilensis), 12 (15 percent) one of Nematoda Spirocamallanus inopinatus, and three (3.75 percent) with the Copepoda Ergasilus bryconis. Monogenoidea presented the highest prevalence and intensity of infestation. The Kruskall-Wallis non-parametric variance analysis showed a significant difference (P < 0.05) in the monthly parasite indexes of A. spiralocirrus, J. amazonensis and T. brazilensis, however no significant difference (P > 0.05) was detected for T. kerri. Evaluation of the management conditions pointed out that monthly capture anaesthesia and hauling procedures may have been responsible for some of the clinical signals such as loss of scales, erosion and no pigments on the caudal fin and cornea opacity, which were the most frequently found injuries in husbandry.

O matrinxã Brycon amazonicus, é uma espécie amplamente cultivada na região Amazônica, entretanto, as doenças parasitárias são praticamente desconhecidas. Este estudo teve como objetivo monitorar mensalmente a fauna parasitológica e as condições de manejo em sistema de cultivo intensivo em canal de igarapé. As coletas foram realizadas mensalmente, durante os meses de setembro de 1997 a janeiro de 1998. O monitoramento das condições de manejo foi realizado observando-se os parâmetros de qualidade de água, procedimentos de despesca, biometrias e anestesia. Oitenta (80) peixes foram amostrados, dos quais, 71 (89 por cento) encontravam-se parasitados com quatro espécies de monogenóideos (Anacanthorus spiralocirrus, Jainus amazonensis, Tereancistrum kerri e Trinibaculum brazilensis), 12 (15 por cento) com o nematóide Spirocamallanus inopinatus e três (3,75 por cento) com o ergasilídeo Ergasilus bryconis. Os monogenóideos apresentaram os maiores valores de prevalências e intensidades de infestação. A análise de variância não paramétrica de Kruskall-Wallis revelou uma diferença significativa (P < 0,05) nos índices parasitários mensais de A. spiralocirrus, J. amazonensis e T. brazilensis, porém para T. kerri não foi detectado diferença significativa (P > 0,05). A avaliação das condições de manejo indicaram que os procedimentos mensais de captura, anestesia e transporte podem ter sido responsáveis por alguns dos sinais clínicos observados durante o cultivo. Os mais freqüentes foram: perda de escamas, erosão e despigmentação da nadadeira caudal e opacidade de córnea.

Parasite fauna monitoring of matrinxã Brycon amazonicus (Spix and Agassiz, 1829) raised in aN intensive husbandry system in a stream channel in the state of Amazonas, Brazil.

The matrinxã, Brycon amazonicus, is one of the main species being used for aquaculture and fishery activities in the Amazonian region, yet little is known about the parasites that cause its diseases. The present study monitored parasite fauna infesting an intensive husbandry system in a stream channel. The collections were carried out monthly from September, 1997 to January, 1998. Water quality parameters, fish removal procedures, as well as biometry and anaesthetic data were observed in order to monitor the management conditions. Of the 80 sampled fish, 71 (89%) were infested with four Monogenoidea species (Anacanthorus spiralocirrus, Jainus amazonensis, Tereancistrum kerri and Trinibaculum brazilensis), 12 (15%) one of Nematoda Spirocamallanus inopinatus, and three (3.75%) with the Copepoda Ergasilus bryconis. Monogenoidea presented the highest prevalence and intensity of infestation. The Kruskall-Wallis non-parametric variance analysis showed a significant difference (P < 0.05) in the monthly parasite indexes of A. spiralocirrus, J. amazonensis and T. brazilensis, however no significant difference (P > or = 0.05) was detected for T. kerri. Evaluation of the management conditions pointed out that monthly capture anaesthesia and hauling procedures may have been responsible for some of the clinical signals such as loss of scales, erosion and no pigments on the caudal fin and cornea opacity, which were the most frequently found injuries in husbandry.

Myxobolus insignis sp. n. (Myxozoa, Myxosporea, Myxobolidae), a parasite of the Amazonian teleost fish Semaprochilodus insignis (Osteichthyes, Prochilodontidae).

A new myxosporean species is described from the fish Semaprochilodus insignis captured from the Amazon River, near Manaus. Myxobolus insignis sp. n. was located in the gills of the host forming plasmodia inside the secondary gill lamellae. The spores had a thick wall (1.5-2 microm) all around their body, and the valves were symmetrical and smooth. The spores were a little longer than wide, with rounded extremities, in frontal view, and oval in lateral view. They were 14.5 (14-15) microm long by 11.3 (11-12) microm wide and 7.8 (7-8) microm thick. Some spores showed the presence of a triangular thickening of the internal face of the wall near the posterior end of the polar capsules. This thickening could occur in one of the sides of the spore or in both sides. The polar capsules were large and equal in size surpassing the midlength of the spore. They were oval with the posterior extremity rounded, and converging anteriorly with tapered ends. They were 7.6 (7-8) microm long by 4.2 (3-5) microm wide, and the polar filament formed 6 coils slightly obliquely to the axis of the polar capsule. An intercapsular appendix was present. There was no mucous envelope or distinct iodinophilous vacuole.

Myxobolus insignis sp. n. (Myxozoa, Myxosporea, Myxobolidae), a parasite of the Amazonian teleost fish Semaprochilodus insignis (Osteichthyes, Prochilodontidae)

A new myxosporean species is described from the fish Semaprochilodus insignis captured from the Amazon River, near Manaus. Myxobolus insignis sp. n. was located in the gills of the host forming plasmodia inside the secondary gill lamellae. The spores had a thick wall (1.5-2 µm) all around their body, and the valves were symmetrical and smooth. The spores were a little longer than wide, with rounded extremities, in frontal view, and oval in lateral view. They were 14.5 (14-15) µm long by 11.3 (11-12) µm wide and 7.8 (7-8) µm thick. Some spores showed the presence of a triangular thickening of the internal face of the wall near the posterior end of the polar capsules. This thickening could occur in one of the sides of the spore or in both sides. The polar capsules were large and equal in size surpassing the midlength of the spore. They were oval with the posterior extremity rounded, and converging anteriorly with tapered ends. They were 7.6 (7-8) µm long by 4.2 (3-5) µm wide, and the polar filament formed 6 coils slightly obliquely to the axis of the polar capsule. An intercapsular appendix was present. There was no mucous envelope or distinct iodinophilous vacuole.