Current data on reproductive biology and population dynamics of the acanthocephalans are scarce mainly in regions from the tropical Pacific. An analysis was done to identify possible factors that influence variation in infection levels of the acanthocephalan Pseudoleptorhynchoides lamothei Salgado-Maldonado, 1976 in its final host, the blue sea catfish Ariopsis guatemalensis (Günther, 1864), and describe its main reproductive traits. A total of 1,094 A. guatemalensis were collected from Tres Palos Lagoon from August 2014 to December 2015. Prevalence of P. lamothei varied from 1.47% to 38.33%, and mean abundance from 0.03 to 4.44 helminths per examined host. In female P. lamothei relative fecundity increased with total length. Temporal variations in P. lamothei infection levels were attributed mainly to changes in host feeding and reproductive behaviour in response to local environmental factors as climatic season, and variations in water temperature., Dolores I. Carpio-Hernández, Juan Violante-González, Scott Monks, Agustín A. Rojas-Herrera, Sergio García-Ibáñez, Jeiri Toribio-Jiménez and Himmer Castro-Mondragón., and Obsahuje bibliografii
The development of the nematode Procamalianus (Spirocamallanus) neocaballeroi (Caballero-Deloya, 1977), an intestinal parasite of the characid fish, Astyanax fasciatus (Cuvier) in Mexico, was studied in the experimental copepod intermediate host, Mesocyclops sp. After the copepod’s ingestion of free first-stage larvae of the nematode, these penetrate into the haemocoel of the intermediate host; they moult twice (on the 3rd and 4-5th day p.i. at 21-22”C) before they attain the third, infective stage. The third-stage larva already possesses the large buccal capsule subdivided into an anterior broad portion with eight spiral thickenings (as observed in lateral view) and a narrow posterior portion, and its tail tip bears three conical processes. The definitive host acquires infection by feeding on infected copepods; in the intestine of this fish, the nematode larvae undergo two more moults (on the 10th and 14-15th day p.i. at 25-32°C) before attaining their maturity. The prepatent period is approximately two months.
Two new nematodes, Paraseuratoides ophisterni gen. et sp. n. (Seuratoidea: Quimperiidae) and Philometra ophisterni sp. n. (Dracunculoidea: Philometridae) are described based on specimens recovered from the intestine and mesentery, respectively, of the swamp-eel Ophisternon aenigmaticum Rosen et Greenwood (Synbranchiformes: Synbranchidae) from a canal of the Papaloapan River in Tlacotalpan, State of Veracruz, Mexico. The genus Paraseuratoides is most similar to Paraseuratum Johnston et Mawson, 1940, differing from it mainly in the absence of a bulbous inflation on the anterior end of the oesophagus and in the structure of the mouth (presence of 6 spines in addition to 6 oesophageal teeth). Neoquimperia Wang, Zhao, Wang et Zhang, 1979 and Wuinema Yu et Wang, 1992 are synonymised with Ezonema Boyce, 1971 and Paragendria Baylis, 1939, respectively, and Haplonema hamulatum Moulton, 1931 is considered a junior synonym of Ichthyobronema conoura Gnedina et Savina, 1930. Philometra ophisterni (only females) is mainly characterised by minute cephalic papillae, a greatly developed anterior oesophageal bulb separated from the cylindrical part of the oesophagus, anterior extension of the oesophageal gland anterior to the nerve ring, and by the character of large caudal projections. This is the first Philometra species recorded from inland fishes in Mexico.