Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

The objective of this work was to identify the species of parasitic nematodes that infect the gonads of female “birdfish” Hyporhamphus naos Banford & Collette, 2001 (Hemiramphidae: Beloniformes). This species of fish is considered key in terms of the local artisanal fishery index, it is economically transcendental for fishermen and regional consumers who annually wait for its arrival in the bay to be consumed. The nematode Philometra Costa, 1845 (Nematoda: Philometridae) was identified parasitizing the female gonads of H. naos. Two immature female nematodes were found (prevalence 8%, mean abundance 0.08 and mean intensity 1). New information is recorded on the distribution of parasitic nematodes of this genus in this area of ​​the tropical Pacific and a new host. This is the first record of Philometra parasitic on female gonads in H. naos fish in Mexico. The first world record was Philometra longa Moravec, Barton & Shamsi, 2021 in the fish Hyporhamphus australis (Steindachner, 1866) and P. inconveniens Moravec, Barton & Shamsi, 2021 in the fish Hyporhamphus melanochir (Valenciennes, 1847) in Australia. The present study extends the knowledge of the composition by species of the Philometrids that parasitize marine fish. The results of this work contribute to the knowledge on the biology, biodiversity and host preference of these parasites in this fish with great regionalization in the consumption of fish species that present a broad gastronomic social identity in these coastal areas in the port of Mazatlan.

Parasitic metazoans were determined in Triportheus angulatus (Spix & Agassiz, 1829) acquired from the "Belén" market in Iquitos, Peru. Thirty individuals of T. angulatus were collected, of which the gills, muscles and digestive tract were analyzed to find parasitic metazoans. The groups of identified parasites were Monogenoidea and Nematoda. Permanent slides cleared in Hoyer's medium were prepared for monogenoids for their identification. In nematodes, semi-permanent slides cleared with lactic acid were prepared. Parasitological indices were calculated for prevalence, intensity, mean intensity and mean abundance. One hundred fifty-one metazoan parasites were collected from T. angulatus acquired from the “Belén” market in Iquitos, Peru. The following monogenoids were identified: Anacanthorus acuminatus Kritsky, Boeger & Van Every, 1992; Anacanthorus chaunophallus Kritsky, Boeger & Van Every, 1992; Anacanthorus Chelophorus Kritsky, Boeger & Van Every, 1992; Anacanthorus euryphallus Kritsky, Boeger & Van Every, 1992; Anacanthorus lygophallus Kritsky, Boeger & Van Every, 1992; Anacanthorus pithophallus Kritsky, Boeger & Van Every, 1992; Ancistrohaptor falciferum Agarwal & Kritsky, 1998; Ancistrohaptor falcunculum Agarwal & Kritsky, 1998, three unidentified species belonging to the genus Jainus: Jainus sp1, Jainus sp2, Jainus sp3; and one species of Nematoda, Procamallanus (Spirocamallanus) inopinatus Travassos, Artigas et Pereira, 1928. The species belonging to nematoda presented the highest prevalence with 53.33% and an average abundance of 1.83 larvae on average. The genus Jainus sp3, presented the highest average intensity of 4.50. Keywords: monogenoids – nematodes – sardine – taxonomy

The aim of the study was to determine the speed of displacement-capture of the food (SDCF) and the bioaccumulation of cadmium in the backbone of Gambusia punctata (Poey, 1854). The study was carried out in the San Juan River in Santiago de Cuba, Cuba. After sampling with five adult specimens, each one was placed in glass aquariums (20 x 20 x 30 cm) with a density of 1 g/L, without continuous flow of water, or oxygenation and room temperature ≈ 29 oC. During 48 h, the swimming pattern was observed, before the provision of breadcrumbs as food in 5 portions of 0.5 g every 3 min. The concentration of Cd in the backbone of G. punctata was quantified. Statistically significant differences were observed in the SDCF between individuals of G. punctata, where the shortest time was 4.7±0.06 s, while the longest corresponded with 5.6±0.04 s. There were no statistically significant differences in the accumulated concentration of Cd in the backbone of G. punctata where the average bioaccumulated concentration was: 0.126±0.006 μg·g-1. The SDCF time was accepted before the sustained swim. The concentrations of Cd (0.0126±0.006 μg·g-1) in the vertebral spine show that they can exist in individuals of the species, since they coincided with the results described. It is concluded that the swimming behavior was accepted, but the bioaccumulation of Cd in the vertebral column could compromise the survival of G. punctata.

The ornamental fish trade is one of the most important economic activities for thousands of people in the Amazon region. Among fish that are exported from Peru, Apistogramma sp., Cichlasoma amazonarum (Kullander, 1983) and Pterophyllum scalare (Schultze, 1823) are highly demanded in the ornamental fish trade activities. To date, in Peru, studies concerning to parasites that affect aquaculture activities are scarce, in that way, the present study registers for the first time in the Peruvian Amazonia the occurrence of Clinostomum sp. parasitizing three species of cichlids. Samples of Apistogramma sp., C. amazonarum and P. scalare were collected in a fish farming pond of the “Amazon Research Center for Ornamental Fishes (ARCOF) in Iquitos, Peru. Analyzed samples revealed the presence of Clinostomum sp. parasitizing the fins of the fish. As some species of cichlids are cultivated in the Peruvian Amazon for exportation as ornamental fish, the presence of this trematode could compromise the health of the fish and to cause mortalities, either, due to susceptibility to predation by piscivorous birds or due to injuries caused by the infection of parasites.

Two new species nematodes (Thelastomatidae) are described. Both parasites of the wild cockroach Blaptica dubia Serville, 1839 (Blattodea, Blaberidae), found in the Horticultural Belt of La Plata, Argentina. Thelastoma simplex sp. n. is characterized by small, pear-shaped amphidia, cuticularized stoma, no teeth, nerve ring anterior to the basal bulb, excretory pore is situated between basal bulb and beginning of the intestine, vulva protuberant in half of body, muscular vagina, amphidelphic, with anal wing and a very long, threadlike caudal appendage. Males with spicules on anal promontory accompanied by a thick, strong gubernaculum, genital papillae in three simple preanal papillae, of which the first is very large, adanal pair and a simple postanal at base of caudal appendage. Blattophila incomptus sp. n. has short stoma with plate and two teeth, large amphidia, excretory pore near base of the basal bulb, nerve ring located at anterior end of the corpus, dilated intestine at anterior end, vulva in half of body, vagina directed anteriorly. Males with a rudimentary pointed spicule, gubernaculum present, male genital papillae arranged in an unpaired preanal and two postanal papillae, the caudal appendage long and filiform.

The main objective of this work was to report the presence of the pentastomid Sebekia sp. collected from Astronotus oscellatus (Agassiz, 1831) "Oscar" acquired in the Belén market, in Iquitos, Peru during the month of June 2021. The work was carried out through the observation, search, identification, measurement and calculation of the parasitological indices of Sebekia sp. collected from the musculature and stomach of 30 adult specimens of A. ocellatus. A prevalence of 20 %, mean intensity of 1.5 and a mean abundance of 0.3 of Sebekia sp was reported. The morphometric measurements obtained show specimens of Sebekia sp. with a mean body length of 1560.29 µm and 650.78 µm in width. The presence of this parasite in the musculature of A. ocellatus raises an alert to the possibility of its accidental ingestion due to the consumption of its meat in preparations that use raw or undercooked meat.

Isopods are ectoparasitic crustaceans of marine and freshwater fish with diverse morphology where taxonomic studies involve a series of methods for collection, fixation and techniques for illustrating the species. These methods are applied in a series of studies involving ecology, distribution, biodiversity and morphology. However, approaches from the perspective of scientific illustration are often lacking in the study of parasitic isopods. This study provides a background on the illustration of these organisms by observing published works and presents the application of mixed color technique in the illustration of these invertebrates. This study combined information from the literature and ichthyoparasitological studies involving taxonomy and scientific illustration. The history of isopod illustrations revealed that some older illustrations present greater visual and scientific elaboration compared to some recent ones, despite presenting greater taxonomic and visually less attractive elements, such as the application of pointillism and finishing of the isopod body, demonstrating that it is crucial to combine scientific knowledge and mastery of the illustrative technique. The illustrations of isopods demonstrate the effectiveness of mixed techniques, allowing overlapping of materials, didactics in the rigorous taxonomic view, highlighting the color preserving morphological aspects, in addition to rescuing a similarity to the first descriptions in colors from 1800-1900. This work is the first to describe a history of scientific representations of parasitic isopods over time and to present the mixed technique as a possibility of scientific illustration for this taxonomic group.

The objective of the study was to describe the predation of the larvae of Aedes aegypti (Linnaeus , 1762 ) by the bioregulator Gambusia punctata (Poey, 1854) under nocturnal conditions. The study was carried out in a domestic drinking water tank with a capacity of 20 000 L. Ten adult females of G. punctata were placed without feeding for 48 h. An infrared night vision HD video camera (version: DV-FR480) was attached and then, after 72 h, 10 A. aegypti mosquito larvae (L3 and L4) were deposited at night time, 5 min in three replicates. The larvae were tied with a generic black polyester thread and introduced at the same time until contact with the water surface. Recognition time (s) and predation of G. punctata were measured. The average recognition and predation by G. punctata on A. aegypti larvae showed statistically significant differences. The predatory capacity of mosquito larvae by G. punctata was instantaneous under night time conditions. It is concluded that the predatory capacity of G. punctata is natural and its recognition by A. aegypti larvae takes place in seconds, which is essential to maintain the biocontrol of this vector agent.

Larvae of the genus Contracaecum can be found in several species of fish. This study aims to analyze the prevalence, incidence and average abundance of Contracaecum sp. in fish, and to relate host species richness to parasite abundance. A total of 2888 specimens of host fish were collected, and only 217 specimens showed Contracaecum sp. infections. A total of 64 species of fish were collected, in which the greatest richness of hosts was evidenced during the dry season. During the dry season, the highest prevalence values ​​of Contracaecum sp. were found in Erythrinus erythrinus (P=43.18%) and Acestrorhynchus sp. (P=17.39%).  The values ​​of high abundance (AM= 0.73) and average intensity (IM= 9.77) were evidenced in Sorubim lima. During this period, the relationship between host richness and occurrence of Contracaecum sp. was also significant. In conclusion, the study showed the occurrence and prevalence of Contracaecum sp. in a great richness of host fishes, mainly species of great commercial importance. The decrease of the river level during the dry season increases the richness of infected hosts.

Bibliography indicates that the larvae of the genus Contracaecum are of zoonotic importance. These papers are based on a single clinical case whose conclusions are doubtful and should be confirmed. In the present work, the results of experimental infections in Balb/cAnN mice, with L3 juvenile of the Contracaecum ogmorhini Johnston & Mawson, 1941 complex, are reported. The helminths were obtained in the stripped weakfish, Cynoscion guatucupa (Cuvier, 1830), the second most important commercial fishery resource in Argentina. The parasites were characterized by morphological and molecular criteria. Their population descriptors were established on a sample of 112 hosts. The potential for migration to the skeletal muscle of the fishes was evaluated and the background on experimental infection of Contracaecum spp. in mammalian hosts is discussed. It is concluded that the third-stage juveniles (L3) of the C. ogmorhini complex, can cause injury in humans only if well defined conditions are met, including that the L3 migrate naturally to the host’s musculature (unproven event), that remain viable after gastric digestion by the host and that finds immunological conditions that allow its survival in the digestive tract of the mammal host.