Distributional patterns of the South American species of Parastacidae (Decapoda, Astacidea)

Abstract

The distributional patterns of the species of the South American freshwater crayfishes of the family Parastacidae were analysed using panbiogeographical track analyses to identify targeted regions of crayfish biodiversity for understanding biogeographical patterns. Two generalized tracks were identified using the track analysis approach: (1) Uruguay and Brazil (Parastacus brasiliensis, P. brasiliensis promatensis, P. buckupi, P. caeruleodactylus, P. defossus, P. fluviatilis, P. gomesae, P. guapo, P. macanudo, P. pilimanus, P. pilicarpus, P. saffordi, P. tuerkayi, P. varicosus); and (2) Central-southern Chile (P. nicoleti, P. pugnax, Samastacus spinifrons, Virilastacus araucanius, V. jarai, V. retamali and V. rucapihuelensis). These areas were exclusive, with no overlap between them. The results indicate the presence of South American Parastacidae crayfish in Atlantic coastal sub-tropical and Pacific coastal temperate wet climate regions with biogeographic similarities to other South American inland water decapods.

An update and review of commensals on Chilean inland water Decapoda

“…Only a single species was reported for both Chile and the Atlantic coasts of Brazil and Uruguay. From a biogeographical point of view, the protozoan species reported for Parastacus pugnax and Samastacus spinifrons would coincide with the geographical distribution range of both species at 33-38°S, in spite of the fact that S. spinifrons inhabits lakes and rivers, and P. pugnax mainly occurs in flooded plains (Rudolph, 2002(Rudolph, , 2013aDe los Ríos-Escalante et al, 2022b). Probably, however, the habitats "lakes and rivers" will have shared zones with the habitat characterized as "flooded plains", such as "flooded plains of rivers", and this would mean that parts of these habitats would be shared between these species, which could explain the presence of Operculigera asymmetrica on both species of crayfish.…”

“…In theory, this site is within the geographical distribution of Parastacus pugnax (cf. De los Ríos-Escalante et al, 2022b).…”

“…In the branchial chamber of Parastacus pugnax from Reumén, Valdivia (39°45 S 73°45 W). Note: According to Rudolph (2013b) and De los Ríos-Escalante et al (2022b), on the basis of the geographical distribution of the various Parastacus spp., the host described from Reumén, would more probably be identified as P. nicoletti.…”

“…A different situation would exist between Parastacus nicoletti and P. pugnax, where Lagenophrys anticthos was reported, which species was also reported for crayfishes in Uruguay and Brazil. The literature mentioned that Parastacus nicoletti and P. pugnax do not share a latitudinal distribution, because the southern distribution limit for P. pugnax is 38°S, whereas the northern limit for P. nicoletti is 39°S (Rudolph, 2013b;De los Ríos-Escalante et al, 2022b). Nevertheless, the presence of Lagenophrys anticthos on both Parastacus pugnax and Atlantic species, such as Parastacus defossus and P. varicosus (Brazil), as well as for P. saffordi (Uruguay), would confirm the proposal of Crandall et al (2000), who mentioned the close evolutionary relationship between Parastacus pugnax with Atlantic crayfish species.…”

“…These descriptions were based on specimens from Valparaiso (33°03 S 71°38 W), a location in the geographical range of Aegla laevis, Parastacus pugnax and Samastacus spinifrons (cf. Rudolph, 2013;De los Ríos-Escalante et al, 2022b). Nevertheless, these decapod populations probably are now extinct, because the central Chilean regions have undergone marked alterations as a result of human activities (Jara, 2006).…”