Parasites of Urophycis brasiliensis (Gadiformes: Phycidae) as indicators of marine ecoregions in coastal areas of the South American Atlantic

Abstract

The potential value of parasites as ecosystem markers was tested by analyzing the metazoan assemblages of Urophycis brasiliensis caught in four locations distributed in three ecoregions of the Warm Temperate Southwestern Atlantic. A total of 5,001 metazoan parasites belonging to 33 species were found. The identified parasites varied across locations in terms of presence, prevalence, and abundance, and their multivariate analyses resulted in clear similarity patterns. No differences were observed between two locations of the same ecoregion, whereas an evident separation of samples was observed across ecoregions in support of the existing hypotheses regarding the ecoregional division of the southwestern Atlantic. We proposed that parasite assemblages, which are composed of several metazoan phyla, are potentially useful as ecosystem indicators. This suggestion is derived from the combined evidence of the evolutionary history and biogeography of multiple lineages, which is expected to be more efficient in capturing recurrent patterns in overall biodiversity than individual lineages. Furthermore, as many parasites have complex life cycles, their distribution patterns are dependent not only on environmental conditions but also on the distribution and population density of all hosts involved in their life cycles, adding further sources of distributional variability that act synergistically to define robust geographical patterns. The selection of long-lived parasites and their comparative analysis provided evidence supporting the existence of three different stocks in the four sampled areas. The best parasite tags were those with low specificity in fish hosts, constituting promising biological tags for the stock discrimination of other fish species in the region.

Parasitological evidence of stocks of Paralichthys isosceles (Pleuronectiformes: Paralichthyidae) at small and large geographical scales in South American Atlantic coasts

“…in the same hosts, except for U. brasiliensis possibly due to the smaller size of Brazilian specimens. These recurrent patterns of suitable parasite tags across host species in the southwestern Atlantic reinforce previous studies in this region showing that parasite assemblages can be used as ecosystem indicators to characterize hosts living if different zoogeographical provinces (Cantatore and Timi, 2015) and, as suggested by Pereira et al (2014) for studies at larger spatial scales, as indicators of ecoregions within zoogeographical provinces.…”

“…They also displayed latitudinal patterns of prevalence and abundance similar to those observed in previously studied host species. Indeed, parasite loads of G. carvajalregorum and C. australe were higher in Argentina than in Brazil in Cynoscion guatucupa (Timi et al, 2005), Pinguipes brasilianus (Timi et al, 2010), Trachurus lathami (Braicovich et al, 2012) and U. brasiliensis (Pereira et al, 2014), whereas the opposite pattern was observed for Hysterothylacium sp. in the same hosts, except for U. brasiliensis possibly due to the smaller size of Brazilian specimens.…”

“…Nevertheless, the use of parasite tags remains unexplored in most regions of the Brazilian sea, despite the need to focus future actions on enhancing fisheries management to improve the regional ocean health (Elfes et al, 2014). In fact, at present only two studies have been carried out between Brazilian localities for the discrimination of stocks of Micropogonias furnieri and Urophycis brasiliensis (Pereira et al, 2014), both comparing fish samples between distant regions with successful results derived from sampling designs covering different biogeographical provinces and ecoregions (Pereira et al, 2014). Similarly, some previous comparisons of parasite communities between fish samples from the regions of Rio de Janeiro, Brazil and northern Argentine waters are also based on large-scale spatial studies (Timi et al, 2005(Timi et al, , 2010Braicovich et al, 2012).…”

Homogeneity of parasite assemblages of Dules auriga (Serranidae) in hydrographically heterogeneous sites

“…The parasite assemblages of D. auriga were, however, similar to those found on other host species in the region in terms of their composition, sharing the same set of dominant species with other sympatric fishes, namely G. carvajalregorum , C. australe and Hysterothylacium sp. These species have been identified as both typical and as indicators of this ecoregion (Pereira et al ., ). The presence of H. aduncum at high loads in the sampled fish is notable.…”

Influence of confluent marine currents in an ecotonal region of the South-West Atlantic on the distribution of larval anisakids (Nematoda: Anisakidae)

“…Lanfranchi et al [ 29 ] included data on other host species recognized as harbouring parasite assemblages representative of neighbouring zoogeographical regions, characterized by these masses of water [ 9 , 33 , 34 ]. These waters, with subtropical and sub-Antarctic origins, affected the structure of parasite communities in the ecotone by acting as sources of infective stages of helminth species (acanthocephalans, nematodes, cestodes) typical of adjacent zoogeographical units, which were considered as reliable indicators to define such transitional regions.…”