Aggregation and negative interactions in low-diversity and unsaturated monogenean (Platyhelminthes) communities in Astyanax aeneus (Teleostei) populations in a neotropical river of Mexico

Abstract

We studied monogenean communities of 11 populations of Astyanax aeneus (Günther) separated by small geographical distances along 60 km of the Lacantún river in Chiapas, Mexico, in February and August 2012. We found 12 monogenean taxa. Amongst these, five species specialist for Astyanax were widely distributed regionally, constituting 90% of the total collected monogeneans, with one of these species dominating most component communities. The high similarities in terms of composition between the component communities (S Jaccard > 60%) as well as in terms of the abundance and composition between infracommunities (S Bray Curtis > 40%), provide empirical evidence that transmission, both between hosts at the same location and between component communities, is high and effective. No resemblance pattern was detected between locations in terms of their spatial distribution. The composition of these communities was spatially and temporally consistent over the two very different weather periods sampled. These communities were not saturated. Our analysis suggests that the potential richness of the infracommunities is proportional to the number of monogenean species available in the component community. We found aggregation in the populations and between monogenean species. Intraspecific aggregation is density dependent, suggesting that intraspecific competition for space is not a limiting factor for the development of the population. We evaluated the associations for each species pair and detected 77% negative interactions (134/177 associations), suggesting that interspecific competition plays an important role in shaping these communities. The negative correlations of abundance between pairs of species contributes to confirmation of competition. Intraspecific aggregation increased relative to interspecific aggregation with richness in the component community, facilitating coexistence of the species. Our results suggest that these are interactive communities, where monogeneans disperse efficiently from a common source, colonize patches (hosts) together, and compete with other species even at low population densities. Finally, the coexistence of these species is favored by the unpredictable recruitment and aggregated use of fragmented resources.

Competition from sea to mountain: Interactions and aggregation in low‐diversity monogenean and endohelminth communities in twospot livebearerPseudoxiphophorus bimaculatus(Teleostei: Poeciliidae) populations in a neotropical river

“…We assessed the level of aggregation of helminth populations to test their influence on determining the local parasite richness within a host population. Further, we assessed whether intraspecific aggregation exceeded interspecific aggregation (e.g., Salgado-Maldonado et al, 2019). Our goal was to explore the factors that might contribute to the richness and coexistence of helminth parasites of P. bimaculatus across 11 localities in the La Antigua River, a neotropical system in Veracruz, Mexico.…”

“…Additional empirical support by Vidal‐Martínez and Kennedy (2000) showed that even relatively small numbers of acanthocephalans can produce a displacement of phylogenetically unrelated intestinal helminths (trematodes and nematodes) in a tropical cichlid fish, Cichlasoma synspilum . We recently described the potential interactions in low‐diversity monogenean parasitic communities in a tropical freshwater fish, Astyanax aeneus , and showed that interspecific interactions can be an important factor for structuring low‐diversity ectoparasitic helminth communities (Salgado‐Maldonado, Mendoza‐Franco, Caspeta‐Mandujano, & Ramírez‐Martínez, 2019). Thus, the extent to which interspecific interactions are important structuring factors for low‐diversity fish ecto‐ and endoparasite communities remains uncertain.…”

Metazoan parasite communities of three endemic cichlid fish species from the upper Grijalva River, Chiapas, Mexico

“…On the other hand, C. grammodes feeds mainly on aquatic insects (e.g., Trichoptera, Odonata, Megaloptera) and small fish that might produce little variation on their community descriptors (species richness, diversity) and infection parameters (mean abundance) between host species (Violante-González et al, 2008a,b;Gómez-González et al, 2015 Kennedy, 1996;Salgado-Maldonado et al, 2005). Generally, helminth communities in freshwater fish are isolationist in structure and stochastic in composition, thus reflecting their low species richness and diversity (see Vidal-Martínez & Kennedy, 2000;Kennedy, 2006;Salgado-Maldonado et al, 2019). This pattern is probably due to several factors, such as geography and geology (contemporary and past) of regions and drainages, different environmental conditions, historical ecology of both hosts and parasites, feeding behavior and specializations of the host, which contribute to the structuration of the communities of parasites (Choudhury & Dick, 2000).…”

“…Overall component communities in the three cichlids were poor in species and number of metazoans, when comparing with other tropical cichlids: Mayaheros urophthalmus (Günther, 1862) group (= Cichlasoma urophthalmum ) (38 species), Parachromis managuensis (34 species), Thorichthys helleri (32 species), Vieja fenestrata (= Cichlasoma fenestratum ) (37 species) and Petenia splendida (27 species) ( Salgado-Maldonado & Kennedy, 1996 ; Salgado-Maldonado et al, 2005 ). Generally, helminth communities in freshwater fish are isolationist in structure and stochastic in composition, thus reflecting their low species richness and diversity (see Vidal-Martínez & Kennedy, 2000 ; Kennedy, 2006 ; Salgado-Maldonado et al, 2019 ). This pattern is probably due to several factors, such as geography and geology (contemporary and past) of regions and drainages, different environmental conditions, historical ecology of both hosts and parasites, feeding behavior and specializations of the host, which contribute to the structuration of the communities of parasites ( Choudhury & Dick, 2000 ).…”

Data on monogenean (Platyhelminth) parasites in 11 populations of Astyanax aeneus (Pisces: Teleostei) in a neotropical river in Chiapas, south Mexico

“… Data source location MEXICO (south of the country), state of Chiapas. Eleven sample locations situated on the opening of streams tributaries to the main Rio Lacantún in the Biosphere Reserve Montes Azules (RBMA), Chiapas, México: [1] Río Tzendales (16°17′ 10.8″ N; 90°53′12.6″ W), [2] Río Manzanares (16°10′14.6″ N; 90°50′36.2″ W), [3] Arroyo Miranda (16°08′08.1″ N; 90°55′14.9″ W), [4] Río Danta (16°09′08.1″ N; 90°54′06.3″ W), (5) Arroyo Lagarto (16°08′14.0″ N; 90°54′24.4″ W), (6) Embarcadero Estación Chajul (16°06′38.4″ N; 90°56′ 23.6″ W), (7) Arroyo José (16°06′50″ N; 90°56′03.3″ W), (8) Río Chajul (16°05′58.2″ N; 90°57′30.1″ W), (9) Río San Pablo (16°06′ 10.0″ N; 91°00′52.2″ W), (10) Río Puerto Rico (16°05′04.4″ N; 91°01′11.2″ W), (11) Río Ixcan (16°07′17.5″ N; 91°05′11.3″ W). Data accessibility Data provided within this article.…”