A new species ofContracaecum(Nematoda: Anisakidae) found parasitizingNannopterum brasilianus(Suliformes: Phalacrocoracidae) andHoplias argentinensis(Characiformes: Erythrinidae) in South America: morphological and molecular characterization of larval and adult stages

Abstract

Nematode species of the genus Contracaecum Railliet & Henry, 1912 have been reported around the world in many species of fish-eating birds and seals. Here, Contracaecum jorgei n. sp. is morphologically described using light and scanning electron microscopy for adults and fourth-stage larvae (L4) found in the bird Nannopterum brasilianus and third-stage larvae (L3) found in the freshwater fish Hoplias argentinensis, both from the province of Córdoba, Argentina. Additionally, sequences of cytochrome c oxidase subunit II were obtained from these specimens and molecular phylogenetic analysis was used to determine its relationships within the genus. The present species is distinguished from other species by the number and disposition of cephalic papillae; shape and size of the interlabia; length of the spicules; and number and arrangement of papillae in the posterior end of the male. Furthermore, in the molecular analyses, sequences obtained from adult L4 and L3 specimens of C. jorgei n. sp. were similar and grouped, forming an independent lineage, thus confirming it as a distinct species. Thus, morphological characteristics associated with molecular data support the proposal of a new species.

Contracaecum nematode parasites in hillstream loaches of the Western Ghats, India

“…Although similar mechanisms are not known in Contracaecum, muscle damage may still reduce the swimming abilities of a fish which From their secondary intermediate fish hosts, Contracaecum has been isolated from a number of species originating from marine (Berland, 1961;Chaturvedi & Kansal, 1977;Guardone et al, 2020;James & Srivastava, 1967;Sood, 2017), brackishwater (Chaturvedi & Kansal, 1977;Motamedi et al, 2019;Sood, 2017), and freshwater (Aydogdu et al, 2011;Chaturvedi & Kansal, 1977;Gholami et al, 2014;Motamedi et al, 2019;Sardella et al, 2020;Sood, 2017) sources. In India, Contracaecum has been isolated from several commercial marine and freshwater fishes, including freshwater catfishes Mystus sp.…”

“…Genus Contracaecum is considered the most diverse group within the family Anisakidae, having a wide geographical distribution, and a host range spanning from invertebrates to vertebrates (Shamsi, 2019). Piscivorous birds and mammals associated with freshwater, brackishwater and marine environments (such as cormorants, pelicans, penguins, and seals) are infected after consuming infested fish, and become definitive hosts of Contracaecum (Borges et al, 2014; D'amelio et al, 2012; Nascetti et al, 1993; Sardella et al, 2020). Definitive hosts shed the parasite eggs through their excrements which are ingested by invertebrates, such as gastropods, cephalopods, polychaetes, copepods, amphipods, and decapods, and serve as the first intermediate hosts for nematodes (Huizinga, 1967; Køie & Fagerholm, 1995; Shamsi, 2019).…”

Genetic diversity of Contracaecum rudolphii sp. A (Nematoda: Anisakidae) parasitizing the European Shag Phalacrocorax aristotelis desmarestii from the Spanish Mediterranean coast

“…The genus Contracaecum Raillet and Henry, 1912 includes species maturing in pinnipeds and waterbirds worldwide, representing the most diverse group of the family Anisakidae ( 1 , 2 ). Considering only the species of the genus maturing in fish-eating birds, 19 species have been so far described as infecting cormorants and pelicans ( 1 , 3 – 10 ). Moreover, several morphospecies of the genus have been demonstrated to include sibling species ( 1 , 2 , 8 , 11 – 13 ).…”

“…atriceps from the north Patagonian coast ( 5 ); C. australe discovered in Ph. brasilianus from Chile and Argentina ( 18 ); and C. jorgei observed in Nannopterum brasilianus from Argentina ( 10 ).…”

Phylogenetic relationship between Contracaecum spp. (Nematoda, Anisakidae) parasitizing cormorants (Aves, Phalacrocoracidae) from Argentina

“…have been reported parasitizing Phalacrocoracidae species in South America so far (Garbin et al 2023). Among them, ve species were reported from shags in Argentina: Contracaecum pelagicum Johnston and Mawson 1942, Contracecum travassosi Guitiérrez 1943, and Contracecum chubutensis Garbin, Diaz, Cremonte, and Navone 2008, parasitizing the Imperial shag Phalacrocorax atriceps (King 1828) from the north Patagonian marine coasts (Gutiérrez 1943; Garbin et al 2008Garbin et al , 2013, Contracaecum australe Garbin, Mattiucci, Paoletti, González-Acuña, and Nascetti 2011, and Contracaecum jorgei Sardella, Mancini, Salinas, Simões and Luque 2020, parasitizing the Neotropic cormorant Phalacrocorax brasilianus (Gmelin 1789) in inland wetlands from Córdoba, Argentina (Garbin et al 2011;Biolé et al 2012;Sardella et al 2020). In addition, specimens described as C. australe was reported parasitizing the Red-legged cormorant Phalacrocorax gaimardi (Lesson and Gamot 1828) from the Ría Deseado, Santa Cruz province, Argentina (Garbin et al 2014).…”