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Zoogeografía de macroinvertebrados bentónicos de la costa de Chile: Contribución para la conservación marina
Abstract
The diversity of marine macroinvertebrates has received increasing attention, although with little emphasis on its biogeographical significance. The present study analyses an updated data base on 1,601 littoral benthic species, belonging to: Demospongiae, Anthozoa, Polychaeta, Mollusca, Crustacea, Echinodermata y Ascideacea, whose records grouped into 10 zones, have been studied from the zoogeographic perspective. The groups best represented along the Chilean coast include the Mollusca (611 species), Polychaeta (403) and the Crustacea (370), with an important influence on its general pattern of biodiversity. This biodiversity showed a mild but progressive increase along the latitudinal gradient from north to south, interrupted by maxima which appear to reflect differences in study effort rather than normal behavior. The degree of relationship between zones showed three faunistic units recently defined by Lancellotti & Vásquez. This arrangement, which was evident in the most diverse groups, became altered in the lesser speciose groups where differences obeyed a pattern of affinity to particular zones within the Transitional Temperate Region. The presence of a zoogeographic break near 41º S, as broadly suggested in the literature, was only seen in data for the Echinodermata and the Demospongiae; other taxa show the existence of a region of transitional character having gradual replacement of species. Within the Regions, the biodiversity showed great homogeneity, contrary to endemism, which reached 52% in the Cold Temperate Region, as a consequence of an important number of single species records (38.2% species recorded in only one zone). This represents the present lack of knowledge of the Chilean fauna, probably overestimating regional endemism, and thus distorting knowledge of local patterns of biodiversity
... Around 60 species of brachyuran decapods can be found along the central coast of Chile (Lancellotti and Vásquez, 2000). Many of them are of commercial value and represent important components of the shore food webs (Morales and Antezana, 1983;Ojeda and Fariña, 1996;Fernández and Castilla, 1997;Palma and Ojeda, 2002;Fariña et al., in press). ...
... Location of the study site and percent cover of the different microhabitats considered in this study. References: (1) Lancellotti and Vásquez (2000); (2) Retamal (1999); (3) Palma et al. (2006); (4) Cerda and Wolf (1993); (5) Leon and Stotz (2004); (6) Wolff and Cerda (1992); (7) Quintana and Saelzer (1986); (8) Fagetti and Campodonico (1973); (9) Fagetti and Campodonico (1971); (10) Manriquez and Cancino (1991); U.D. = unpublished data. CW = carapace width; CL = carapace length. ...
In highly mobile animals post-settlement dispersion of juveniles can strongly influence the observed patterns of abundance and distribution. To explore the relative importance of factors regulating the use of habitat by crabs we performed a multi-species manipulative experiment in a subtidal environment of the central Chilean coast. First, demographic patterns were established by performing a year-round crab survey in three discrete and well-known subtidal crab habitats: (1) algal turf, (2) cobbles and (3) shell hash. Second, habitat preferences were experimentally evaluated using concrete trays that were filled with different substrate types that simulate natural habitats. Settlement and recruitment rates were estimated from experimental trays that were left in the field and surveyed after 2 weeks (complete experiment was repeated 7 times throughout 1 year). Third, mortality, due to predation, was assessed by covering 50% of the trays with a 4-mm mesh-size screen that excluded large predators (i.e., fishes, shrimps). Fourth, habitat colonization rates were evaluated by quantifying the arrival, into open trays, of large juveniles (secondary dispersal). The most abundant species in this system (Paraxhantus barbiger, Cancer setosus, Taliepus dentatus and Pilumnoides perlatus) displayed clear habitat preferences at the time of settlement, evidenced by differences in density of recruits among habitats. Recruitment regulation by predation seemed to explain the observed patterns in only one case. For most species, however, evidence of ontogenetic change in the use of habitat, through active habitat redistribution by large juveniles, was detected. Thus, secondary dispersal among habitats seems to outweigh the influence of megalopae's habitat selection and post-settlement mortality as responsible for the observed demographic patterns.
... In this study, the megalopae of one of the most abundant crab species in the shallow subtidal environment along the coast of Chile, Paraxanthus barbiger (Poeppig 1836) (Palma et al. 2003a(Palma et al. , b, 2006Pardo et al. 2007), is described for the Wrst time. This species is distributed from Callao, Perú to Chonos archipelagos (48°S) (Retamal 1981) sharing his habitats with, at least, eight more xanthoid species across to Chilean coast (Lancellotti and Vásquez 2000). Several of them, such as Gaudichaudia gaudichaudii (H. ...
... In other species of the family Xanthidae, for example in Homalaspis plana, which shares most part of its distribution with P. barbiger (Lancellotti and Vásquez 2000), the presence of these hooks has not been described (Fagetti 1970). Furthermore, the setation patterns in H. plana are signiWcantly reduced on the antennule's peduncle; maxillule's coxal endite; maxila's endopod and scaphognathite; Wrst maxilliped's endopod and epipod; second maxilliped's endopod and protopod; the third maxilliped; plus the absence of setation in the maxillue's protopod, and Wrst maxilliped's coxal and basal endite (Fagetti 1970). ...
... The purple mussel P. purpuratus is a dominant primary space holder at middle and low elevations in rocky intertidal habitats on the southeastern Pacific coast (Lancellotti and Vasquez 2000;Thiel and Ullrich 2002). The carnivorous gastropod A. monodon uses this mussel as one of its main prey (Soto et al. 2004;Averbuj et al. 2021;Büchner-Miranda et al. 2021). ...
Predators affect their prey through consumptive and non-consumptive effects (NCEs). Regarding marine NCEs, predator chemical cues (e.g., exudates) can trigger various anti-predator responses in prey that can vary in magnitude according to the intensity of the perceived cues. Specimens of the mussel Perumytilus purpuratus were exposed to seawater that held different densities of the predatory snail Acanthina monodon as a proxy for predator cue intensity. The response of mussels was quantified in terms of valve gape size (VGS), clearance rate (CR), and oxygen consumption rate (OCR). The results showed that mussels reduced VGS, CR, and OCR as a function of the intensity of the predator exudates to which they were exposed. These results suggest that mussels are not only able to detect predators through their chemical exudates but can also detect the intensity of the predatory signal and thus respond physiologically (CR, OCR) and behaviorally (VGS) in accordance to the potential predation risk. These responses may have cascading effects at the community level, given that mussels are foundation species.
... The main benthic taxa are the classes Polychaeta, Bivalvia and Gastropoda. The composition of benthos is consistent with that observed in other ecosystems with similar characteristics in southern Patagonia (Espoz et al. 2008) and with the zoogeographic biodiversity described in Chile for the Chiloé Archipelago (Lancellotti and Vásquez 2000). The distribution and community structure of benthic organisms depends largely on the type of substrate, the size of the sediment particle, and the distance from the coast (Jaramillo et al. 1998;Cañete et al. 2010). ...
The coastal wetlands of northern Chilean Patagonia are relevant sites for the conservation of migratory waterbirds. The aim of this paper is to compare different marine coastal wetlands to identify which factors influence the structure of bird assemblages. Sediment samples were collected, and the birds were surveyed in four wetlands: Chullec, Curaco de Vélez and Quinchao on Quinchao Island, and Putemún on Chiloé Island in 4 seasonal sampling campaigns. The composition of the sediment did not change during the year, with a predominance of sandy sediments except in Putemún where gravel dominates. The size of the sediment particle decreased from the upper (0 to 30 m) to the lower (100 m) intertidal. The abundances of benthic organisms varied between intertidal levels in all wetlands and seasonally in Chullec and Curaco de Vélez, being lower during warm seasons. Thirty-four species of birds were recorded with Anatidae, Laridae and Scolopacidae showing the highest species richness. A principal component analysis clustered the wetlands of Quinchao Island and the variables that account for 35.8% of the variance are sandy sediments, the presence of Scolopacidae, Laridae, Furnariidae and Haematopodidae among birds and Polychaeta, Malacostraca and Enopla in the benthos. In the wetlands of Quinchao Island there was a relationship between the composition of the sediment, distribution, and type of benthic communities with the presence of some bird taxa. The bird assemblages change seasonally and were similar to each other during warm seasons, probably due to the availability of food for migratory birds and sediment characteristics.
... Separation, identification, and counting of the different species or taxa were carried out with a stereomicroscope (Olympus SZ). Identification of the individuals was carried out using specialized literature (Cerda and Castilla 2001;Fauchald 1977;Forcelli 2000;Lancellotti and Vásquez 2000;Retamal 1981;Rozbaczylo 1980) and verified in the World Register of Marine Species (http:// www. marin espec ies/ org). ...
The climate crisis has accelerated the frequency and intensity of droughts in the Mediterranean areas, impacting the hydrology and the ecology of their basins. Maule River is the largest watershed in the Chilean Mediterranean Zone. The growing anthropic and environmental pressure has led to changes in the structure and function of its terrestrial ecosystem. However, little is known about its influence on aquatic ecosystems. The effect of the recent extreme drought on the streamflow and its influence on water quality and the benthic macroinvertebrate community structure were evaluated in the Maule River’s lower section. Beyond temporal and spatial fluctuations, healthy and permanently well-oxygenated waters prevailed in the study area. However, during the megadrought period, evidenced by a significant decrease in both precipitation and river streamflow, a greater salt wedge influence was observed, at least, in the last 7 km of the river. Although with certain asynchrony, a change in the structure of the benthic macroinvertebrate community was observed in the upstream stations. This marinization reveals an increase in the domain of marine taxa associated with the Polychaeta group and a clear decrease in typical freshwater Oligochaeta individuals. This modification in the structure of the benthic community is expected to affect the function of this estuarine system. The results presented here highlight the importance of considering the variability associated with biological components for the management of water resources and related ecosystem services, considering that one of the main problems associated with changes in land use and the pressures caused by the climate crisis is the decrease in the quality and availability of water in this and other Mediterranean basins globally.
... The vast coastline of Chile (ca. 4200 km long) covers a large part of the Southeastern Paci c Ocean from the 18ºS to ca. 56 ºS (Lancellotti & Vasquez, 2000). From ca. 42ºS to the equator, the region is in uenced by the Humboldt Current System which provides nutrient-rich, and cold waters (Echevin et al., 2012;Montecino et al., 2006). ...
Most biodiversity studies of octocorals have focused on tropical shallow waters, particularly from Mexico to Peru, and more recently in Chile. The first description of a Chilean octocorals dates back to the H.M.S Challenger expedition in 1873–1876. Since then, only few descriptions of new soft coral species from this region have been published. In addition, the taxonomic status of most gorgonians reported from the temperate Pacific coast of South America is dubious due to the loss of the original type material for most taxa. Here, we use morphological characters and nuclear and mitochondrial markers to reevaluate the taxonomy of the Chilean gorgonians Phycogorgia fucata and Leptogorgia chilensis , and describe a new species named Leptogorgia pichicuyensis sp.n. We present the first description of their latitudinal distribution patterns. Our results support the monophyly of the Chilean gorgoniids investigated, and the provisional placement of P. fucata with other species of the genus Leptogorgia in the absence of further specimens of Phycogorgia in GenBank. Our distribution analyses reveal a clear biogeographic break congruent with the Central Chile and Araucanian marine ecoregions. Overall, our study provides the first integrative taxonomic study of Southern Eastern Pacific cold-water gorgonians suggesting a higher number of species than expected for this underexplored region.
... Several species of brachyuran decapods are found along the coast of central Chile (Lancellotti & Vasquez 2000) that play an important ecological role in the intertidal and subtidal communities. In these systems, brachyuran crabs are important consumers (scavengers and predators) and are also part of the diet of other predators, mainly fishes (Castilla 1981, Fariña & Ojeda 1993, Ojeda & Fariña 1996, Palma & Ojeda 2002. ...
Aim
Patterns of benthic biodiversity at the macroecological scale remain poorly characterised throughout the Chilean latitudinal gradient, in part due to the lack of integrated databases, uneven sampling effort, and the use of species richness alone to quantify biodiversity. Different diversity measures, encompassing taxonomic and functional components, may give us extra information on biodiversity relevant to conservation planning and management. Thus, evaluating the spatial complementarity of these measures is essential.
Location
Coast and continental shelf of Chile.
Methods
The latitudinal gradient of Chile was divided into five ecoregions according to the Marine Ecosystems of the World classification. Using a 55 × 55 km equal area grid, we estimated the incidence coverage‐based estimator (ICE), taxonomic distinctness (Δ⁺) and three measures of functional diversity: functional richness (FRic), functional evenness (FEve) and functional divergence (FDiv). For each measure, we described spatial patterns, identified hotspots, evaluated hotspot congruence and evaluated complementarity between measures.
Results
Diversity patterns varied between ecoregions and over the latitudinal gradient. ICE and Δ⁺ peaked in the Chiloense and Channels and Fjords ecoregions. Δ⁺ and FRic present a similar pattern at mid‐latitudes. FEve showed a contrary pattern, principally with FRic. Areas with high numbers of hotspots differed spatially according to each metric, and three latitudinal bands were observed. ICE, Δ⁺ and FRic were positively correlated, but the hotspot overlap at the grid cell level was more limited.
Main Conclusions
The complementarity between taxonomic and functional diversity measures is limited when we observe the overlap between grid cells representing hotspots. However, some regions are consistently identified as highly diverse, with the Magellanic Province (Chiloense and Channels and Fjords ecoregions) being the most important for the richness, taxonomic and functional diversity of benthos. Confirmation of the importance of this region can help prioritise conservation efforts.
La intensificación de los trabajos de Oceanografía Biológica en los últimos 15 años hace indispensable contar ya con listas faunísticas que permitan a los investigadores tener líneas de referencias sobre las especies que habitan nuestro mar. Desgraciadamente no siempre es fácil elaborarlas y estamos conscientes de que cualquier intento que se realice, por mínimo que sea, no podría contener la totalidad de las especies existentes y ni siquiera podríamos en un plazo prudencial dar listas completas que contuvieran la totalidad de las especies descritas.
Rissoiform gastropods from southwestern South America (Peru to Tierra del Fuego) and Juan Fernandez Islands are described and additional records are given. Taxa are also described for South Georgia and the Falkland Islands and new locality records of previously described taxa are listed from those areas. The southwestern South American fauna described consists of 10 species of Eatoniellidae comprising nine species of Eatoniella, seven of these new and one of which is in the subgenus Albosabula, and one new species of Pupatonia, the first record of the latter genus outside New Zealand. There are two species of Cingulopsidae; one, a species of Skenella, is new. The 15 taxa included in the Rissoidae (subfamily Rissoinae only) comprise 1 new species each of Pusillina (Haurakia), Powellisetia, and Manzonia (Alvinia) and 12 species of Onoba, 8 of which are new. A single new species of Barleeia (Barleeidae) and Rissoella (Rissoellidae) is also described and an Amphithalamus (Anabathridae), close to A. inclusus Carpenter, is recorded. Three new taxa are described from Juan Fernandez Islands, one Eatoniella and two rissoids tentatively included in Onoba. New species of Eatoniella and Skenella are described from South Georgia. The biogeography of the fauna is briefly discussed. The South American taxa as far north as latitude 42°S are similar to those encountered on sub-Antarctic islands, whereas north of latitude 42°S the few species present are like those of southern California and Mexico. A replacement name, Eatoniella afronigra, is provided for the South African eatoniellid Rissoa nigra Krauss, 1948, a secondary homonym of Paludestrina nigra Orbigny, 1840, also an Eatoniella.