Zoogeographic Barrier Research Articles

Diversity under a magnifier lens: the case of Typhlotanaidae (Crustacea: Tanaidacea) in the N Atlantic

Research focusing on ‘stout-bodied’ typhlotanaids collected from several sites around Iceland and adjacent N Atlantic region has resulted in the description of 15 species new to science, as well as the creation of eight new genera. Typhlotanais eximius Hansen, 1913 is redescribed and transferred to a new genus, while Typhlotanais crassus and Peraeospinosus adipatus are transferred to the genus Larsenotanais. The morphological and the molecular data were combined to consolidate and confirm the validity of the results obtained from both approaches. The polyphyletic nature of the Typhlotanaidae and its serious of its taxonomic diversity are emphasized, although molecular analysis reveals that the ‘stout-bodied’ Typhlotanaidae form monophyletic clade. Depth and temperature are identified as the main environmental parameters determining the distribution of this group of Typhlotanaidae. Several species are clearly associated with the shelf and upper bathyal of Iceland. The Greenland-Iceland-Faroe Ridge is shown to be a distinct zoogeographical barrier for typhlotanaids inhabiting the deeper slope and abyssal regions around Iceland.

Climate, not Quaternary biogeography, explains skull morphology of the long-tailed macaque on the Sunda Shelf

Sundaland, comprising the low-lying Sunda Shelf, the major islands of Borneo, Sumatra, and Java, as well as many smaller surrounding islands, formed a contiguous landmass through much of the Pliocene and Pleistocene. Subsequent late-Pleistocene rising sea levels have often been invoked as major zoogeographic barriers to gene flow and associated phenotypic and taxonomic divergence of Sundaic mammals. However, previous examinations of mammalian biogeography have painted a complex picture, suggesting that mammalian diversification in the region cannot easily be explained by a single overarching biogeographical phenomenon. Instead, it may be that the significant climatic changes and their concomitant impacts on local environments were the more significant control. In this context, we study adult skull morphology of a widely distributed primate in insular and continental Southeast Asia, the long-tailed macaque (Macaca fascicularis), using a 3D geometric morphometric (GM) approach. We used principal component analysis and linear discriminant function analysis to analyze the associations between morphological divergence and island biogeography, taxonomy, and phylogeny. Reduced rank regressions (RRR) were employed to investigate associations with climate of the present and last interglacials and the last glacial maximum (LGM). There was very poor morphological divergence and discrimination among specimens from different biogeographical zones. There was also large overlap between M. fascicularis subspecies in skull size and shape, with M. f. fascicularis occupying the largest range of size and shape variation, consistent with its wide geographical distribution. Nonetheless, sundaic M. f. fascicularis and M. f. philippinensis, restricted to the Philippines, were successfully discriminated on size and shape, supporting the latter as a valid subspecies. There was moderate morphological differentiation associated with the deepest split in mitochondrial DNA lineages (M. f. aureus versus the rest) in skull size and shape. Contrary to biogeography, we detected strong associations between skull morphology and climate. Skull form (size and shape combined) was better explained by climate closer to present conditions and correlated most strongly with the current interglacial, even though past climatic conditions do show correlations with cranial morphology. We found no strong evidence that cranial and mandibular variation in M. fascicularis consistently tracks insularity caused by Quaternary sea level change. Instead, the morphological overlap evident in our sample indicates connections between subspecies and is consistent with the history of Sundaland as a single landmass for large portions of the Quaternary.

Large-scale connectivity of the sandy beach clam Mesodesma mactroides along the Atlantic coast of South America, and climate change implications

The yellow clam Mesodesma mactroides is a cool-water species that typifies sandy beaches of the Southwestern Atlantic Ocean (SAO), which embraces one of the strongest ocean warming hotspots. The region is influenced by the Rio de la Plata (RdlP), which represents a zoogeographic barrier that restricts its larval exchange. We investigated yellow clam larval connectivity patterns using an individual based model (IBM). The IBM combined outputs from a 3D hydrodynamic model with a clam submodel that considered salinity- and temperature-dependent mortality for the planktonic larvae. Connectivity across the RdlP estuary occurred only for larvae released in spring during a strong La Niña event. Mortality due to freshwater precluded larval transport across the RdlP, whereas larval mortality induced by warmer waters reduced connectivity, leading to self-recruitment in most areas. Warming acceleration in this hotspot could further restrict larval connectivity between populations in the SAO, with conservation implications for this threatened species.

Tityosteus, a marine fish (Arthrodira, Homostiidae) from the Emsian of Aragón, Spain, and its distribution

A right marginal plate (over 11 cm long) of Tityosteus cf. rieversae Gross, 1960, emend., has been found in the late part of the Early Emsian (late Zlichovian) in the Mariposas Fm. of the Eastern Iberian Cordillera in southern Aragón. The palaeoecological conditions correspond to a hemipelagic ensialic basin, with predominant elements of Hercynic biofacies but still with photic bottom. The Emsian genus Tityosteus is now known from the Hunsrück Schiefer of Germany and the closely connected Ibero-Armorican Trough and also from the more distant Minusinsk Basin of southern Siberia. Palaeo-oceans between western Europe and southern Siberia were no zoogeographical barriers for these large, possibly microphagous fishes in open sea. The name of the type species of Tityosteus is emended.

Zoogeographical barriers causing discontinuous osteometrical variations in the northern treeshrew skulls.

Morphological variation of the skull was examined in the northern treeshrew (Tupaia belangeri) from various localities across Southeast Asia. Through a multivariate analysis, the treeshrews from South Vietnam exhibited distinct morphological characteristics compared to other populations from Thailand and Laos, and Malaysia. The plots of the specimens of North Vietnam are not randomly mixed with Thailand plots segregation in the scatteregrams of canonical discriminant analysis. Since the skulls of the population from North Vietnam were morphologically similar to those form central Laos and northern and northeastern Thailand, the zoogeographical barrier effect of Mekong River was not clearly confirmed. The population of the Kanchanaburi in western Thailand is clearly smaller in size compared to the other populations. The southern border of the distribution of this species is determined by the Isthmus of Kra or Kangar-Pattani Line. In the northern treeshrew, which is distributed from southern China to Bangladesh and southern Thailand, we have detected osteometrical geographical variation driven by geography. These results indicate that the skull morphology in the Tupaia glis-belangeri complex distinctively differs in South Vietnam, western Thailand, and southern Thailand. The zoogeographical barrier and factor separating these districts are expected to clarify in the future.

<p class="ZootaxaTitle"><strong>Trichoptera of Saur and Tarbagatay Mountains (Kazakhstan)</strong></p>

A Trichoptera list compiled for the first time for the Saur and Tarbagatai Mountains, northeastern Kazakhstan, comprises 38 species of 24 genera in 13 families. The region is notable as a contact zone for Siberian, Boreal, and Central Asian Trichoptera faunas. The study reveals numerous limits of distribution for species comprising more than half of the local fauna at very low level of local endemism. The fauna is poor and probably resulted from post-glacial colonization through some zoogeographic barriers.

Larval and adult fish assemblages along the Northwest Passage: the shallow Kitikmeot and the ice-covered Parry Channel as potential barriers to dispersal

Climate warming and sea ice decline are expected to increase fish population movements in the circumpolar Arctic, including across the Canadian Arctic Archipelago (CAA). Knowledge gaps on present distribution, habitat uses, barriers to dispersal, and population connectivity along the Northwest Passage (NWP) limit science-based management of fish in the North American Arctic. Pelagic trawl, bottom trawl, and ichthyoplankton net collections from the US Beaufort Sea to Baffin Bay between 2005 and 2017 are used to map fish distribution along the NWP and identify potential zoogeographic barriers. In the Kitikmeot (southern CAA), the combination of shallow depths, sub-zero temperatures and slow water circulation may represent a physical barrier reducing the dispersal of marine fish between western and eastern regions. In contrast, the Parry Channel (northern CAA) may exemplify a disappearing sea ice barrier as climate warming unfolds and allow new genetic exchanges.

On the taxonomic structure and variability of Macropsidius involutus Dlabola, 1963 (Homoptera: Cicadellidae: Macropsinae)-morphology and calling signal pattern.

Variability of genitalia shape and male calling signal pattern in Macropsidius involutus from 10 localities in South-eastern Europe (the Crimea, the Lower Volga Region), Kazakhstan, and Kyrgyzstan was investigated. Variability of pygofer processes, penis shape, and signal pattern clearly has a geographic component, but none of these traits clearly supports subdividing this species into different subspecies unequivocally. M. involutus was found at altitudes from 0 up to ca. 2000 m a. s. l. in steppes and deserts in the plains and in steppe zones of mountains. Apparently, different environmental conditions in different parts of its range led to divergence of local populations, but the absence of zoogeographical barriers between them makes possible gene exchange and thus prevents emergence of clearly delineated subspecific taxa.

Genetic analysis of samples from wild populations opens new perspectives on hybridization between long-tailed (Macaca fascicularis) and rhesus macaques (Macaca mulatta).

In the past decade, many researchers have published papers about hybridization between long-tailed and rhesus macaques. These previous works have proposed unidirectional gene flow with the Isthmus of Kra as the zoogeographical barrier of hybridization. However, these reports analyzed specimens of unknown origin and/or did not include specimens from Thailand, the center of the proposed area of hybridization. Collected specimens of long-tailed and rhesus macaques representing all suspected hybridization areas were examined. Blood samples from four populations each of long-tailed and rhesus macaques inhabiting Thailand, Myanmar, and Laos were collected and analyzed with conspecific references from China (for rhesus macaques) and multiple countries from Sundaic regions (for long-tailed macaques). Ninety-six single nucleotide polymorphism (SNP) markers specifically designed to interrogate admixture and ancestry were used in genotyping. We found genetic admixture maximized at the hybrid zone (15-20°N), as well as admixture signals of varying strength in both directions outside of the hybrid zone. These findings show that the Isthmus of Kra is not a barrier to gene flow from rhesus to long-tailed populations. However, to precisely identify a southernmost barrier, if in fact a boundary rather than simple isolation by distance exists, the samples from peninsular Malaysia must be included in the analysis. Additionally, a long-tailed to rhesus gene flow boundary was found between northern Thailand and Myanmar. Our results suggest that selection of long-tailed and rhesus macaques, the two most commonly used non-human primates for biomedical research, should take into account not only the species identification but also the origin of and genetic admixture within and between the species.

Geographical variation in the skeletal morphology of red jungle fowl

ABSTRACT1. The skulls and postcranial skeletons of the red jungle fowl (Gallus gallus) were compared osteometrically between the populations from North and South Vietnam, North and Central Laos and Southeast Bangladesh. The populations include the three subspecies of G. g. spadiceus, G. g. gallus and G. g. murghi and were sampled to reveal the geographical morphological variations among populations in G. gallus.2. The morphometric characteristics of subspecies murghi could be clearly distinguished from those of the other subspecies using a canonical discriminant analysis. However, the size and shape of the skull of the gallus population from South Vietnam were not statistically different from that of the subspecies spadiceus from North Laos. The canonical discriminant scores also clearly indicated that there were morphological similarities in the skulls of the populations from North Laos and South Vietnam.3. From the results, therefore, it is concluded that red jungle fowls do not exhibit high levels of osteometric variation between geographical localities at least within the Indochinese Peninsula.4. This contrasts with previous studies which have described these subspecies as having various external morphological differences and have argued that zoogeographical barriers exist between the north and south areas of the Indochinese Peninsula.

Population genetic structure in the endemic cyprinid fish Microphysogobio alticorpus in Taiwan: Evidence for a new phylogeographical area

The Formosa Bank is a significant zoogeographical barrier for the freshwater fish in Southern Taiwan. Here, we present population genetic structure analyses on Microphysogobio alticorpus populations in Taiwan, and biogeographic pattern to infer the relationship between historic dispersal geological dynamics. A total of 24 haplotypes were genotyped for mitochondrial CR + cyt b region in 134 specimens collected from 9 populations. Relatively high levels of haplotype diversity (h = 0.896) and low levels of nucleotide diversity (π = 0.005) were detected in M. alticorpus. Two major phylogenetic haplotype groups, Clade N1+N2 and S, were revealed and estimated to diverge about 0.121 myr (million years) ago. Haplotype network and population genetic analyses indicated significant genetic structure (FST = 0.876), largely concordant with the geographical location of the populations. According to SAMOVA analysis, M. alticorpus populations were divided into five units that can be explained by episodes of dispersal and population expansion followed by population fragmentation and restricted gene flow. The results of the topological pattern and network suggested that the Kaoping River was the first habitat colonized by the ancestor of M. alticorpus, before the northward dispersal.

A New Species ofAnillinusCasey from the Oak Ridge Area West of the Appalachian Mountains in Tennessee (Coleoptera: Carabidae: Trechinae: Bembidiini)

ABSTRACT A new species of Anillinus Casey, 1918, is described from the Oak Ridge area, Roane County, Tennessee, in the eastern United States. Based on the presence of two patches with effaced microsculpture on the vertex, Anillinus inexpectatus, new species, belongs to the Anillinus loweae-group of species. Within this group, a patch of long setae on the ventral margin of the median lobe of the aedeagus places the new species close to Anillinus steevesi Barr, 1996. Modifications to a previous key for the A. loweae-group species are provided for identification of the new species, and zoogeographical considerations and biogeographical barriers for the A. loweae-group species are discussed.

Ecological Niche Conservatism in Doucs (Genus Pygathrix)

The impressive diversity and unique distribution of primate taxa in Southeast Asia creates a region of interesting biogeography and evolutionary history that remains poorly understood. The three species in the Asian colobine genus Pygathrix (P. cinerea, P. nemaeus, and P. nigripes) appear to follow the unique distribution pattern, replacing one another along the north–south axis. However, the evolutionary history and taxonomic status within Pygathrix is currently debated. We constructed climate-based ecological niche models (ENMs) for the three species, using six environmental variables, to confirm that the bioclimate envelopes of Pygathrix cinerea, P. nemaeus, and P. nigripes follow the north–south gradient. We also used the ENMs to test whether the three species lack ecological exchangeability, meaning differentiation among factors that define the fundamental niche, and whether they exhibit ecological niche conservatism, or the tendency for related species to differ less ecologically than might be expected by the climate available to each species. Our ENMs for Pygathrix followed a north–south gradient as expected, with P. nemaeus extending from ca. 14°N to 21°N, P. cinerea from 14°N to 16°N, and P. nigripes from 11°N to 13.5°N. This study presents the first use of ENMs for doucs that yield significant predictive ability based only on climatic variables. The models are significantly different for all three species, supporting a lack of ecological exchangeability between them, as well as the recent elevation of Pygathrix cinerea to species status. Importantly, Pygathrix cinerea and P. nemaeus show evidence of ecological niche conservatism, which lends support to the occurrence of an allopatric speciation event. This result also suggests that the current overlapping distribution of Pygathrix cinerea and P. nemaeus is the result of secondary contact. The north–south distribution gradient, which exists in similar form among other groups of sister taxa in the region, may be attributed to a zoogeographic barrier, vicariance, or current or historical climatic shifts.

Population connectivity among geographic variants within the Lutjanidae (Pisces) of the Mexican Pacific coast through fish scale shape recognition

Fish scale shape was used to identify geographic variants among Lutjanidae ( Lutjanus argentiventris, L. guttatus and L. peru ). Specimens were collected from three different geographic areas, north to south of the tropical Pacific coast of Mexico: Puerto Vallarta (PV), Manzanillo (MA) and Caleta de Campos (CC). Configuration of landmark coordinates of fish scales were scaled, translated and rotated using generalized procrustes analysis, followed by principal components analysis of resulting shape coordinates. Principal component scores were submitted to cross-validated discriminant analysis to determine the efficacy of scale landmarks for discrimination by geographic variants. This was done with shape and form (shape plus size). PV and MA were recognized as one population different from the CC sampling area. Using only shape (without size), identification rates predicted geographic variant membership much better than chance (91.3%, 70.6% and 85.4% for L. argentiventris, L. guttatus and L. peru , respectively), and taking size into account, classification is somewhat improved (90.6%, 80.1% and 87.5% for L. argentiventris, L. guttatus and L. peru , respectively). Consistency of the two populations for the three species shows non-fortuitous events. Population discrimination confirmed previous genetic studies that show a zoogeographic barrier between the North Equatorial Current and the California Current. The method is non-destructive, fast and less expensive than genetic analysis, thus allowing screening of many individuals for traceability of fish.

Fish community and bioassessment responses to stream network position

If organisms move beyond the boundaries of local sampling units, regional metacommunity dynamics could undermine the ability of bioassessment studies to characterize local environmental quality. We tested the prediction that fish dispersal influences local fish community structure and bioassessment metrics as a function of site position within stream networks. We evaluated fish community data from the US Environmental Protection Agency’s Regional Environmental Monitoring and Assessment Program in West Virginia, USA, to compare the influences of stream network position, ecoregion, basin, and stream size on local fish community composition. We assigned sites to 1 of 3 stream network positions: 1) main channels (MC, n = 12) encompassed streams with upstream catchment areas >200 km2, 2) mainstem tributaries (MT, n = 43) flowed into MC-sized confluences within 15 fluvial km, 3) headwater tributaries (HT, n = 31) lacked such riverine confluences within 15 fluvial km. MT and HT sites had similar upstream catchment sizes and landuse gradients, but species richness was greater in MT sites than HT sites, whereas MT and MC sites were not different in this regard. Three bioassessment metrics were greater in MT sites than HT sites (intolerant species richness, cyprinid species richness, benthic species richness), but a multimetric index of biotic integrity did not differ among stream network positions. Ordinations revealed that fish community composition was organized primarily by zoogeographic basin (Monongahela River basin, New River basin, Ohio River basin), ecoregion (Central Appalachian Plateau, Western Appalachian Plateau, Ridge and Valley), and stream size. Riverine specialists were more abundant in MT than HT sites and were more abundant in basins connected to the Ohio River than in basins isolated from the Ohio River by a large waterfall (New River). Our results suggest that contemporary dispersal among streams influences fish community composition over small spatial scales (101 km), historical dispersal constrained by zoogeographic barriers influences community structure over larger areas (102 km), and contemporary dispersal by fishes influences certain metrics commonly used in bioassessment programs.

Patterns of zooplankton diversity through the depths of the Arctic’s central basins

Metazoan zooplankton diversity is characterized for the oceanic environments of the Arctic Ocean, specifically the deep Nansen, Amundsen, Makarov and Canada Basins. Our species inventory is based on original records from 134 locations where stratified sampling of the entire water column was conducted from the surface to the bottom (or a maximum of 3,000 m) during seven icebreaker expeditions (RV Polarstern, 1993-2007, USCGC Healy, 2005) and two older expeditions of the Russian drifting ice stations North Pole 22 and 23 (1975-77). Representatives of eight large metazoan taxa, including Cnidaria, Ctenophora, Mollusca, Annelida, Nemertea, Crustacea, Chaetognatha, and Larvacea, all predominately oceanic species, are registered, with a total of 174 species. Crustaceans strongly dominate in terms of the species number (70%), and copepods are the most diverse group amongst them. Comparison with the historical data suggests that the composition of epi- and mesopelagic zooplankton is relatively well characterized to date, while a considerable number of species we encountered in the bathypelagic layers were either unrecorded before, or undescribed. There appears to be no zoogeographical barrier between the Eurasian and Canadian basins throughout the entire depth range. All deep-water and endemic species are found on both sides of the Lomonosov Ridge, suggesting effective exchange of the deep fauna across the ridge. Notable differences in the species composition in the upper and midwater layers are related to the occurrence of Atlantic and Pacific expatriates advected with their respective waters either into the Eastern or Western Arctic. A pronounced increase in Pielou’s evenness (J'), Shannon’s diversity (H'), and Margalef’s species richness (d) indices with depth, with a maximum occurring within the Atlantic layer, followed by a decrease in the deeper layers, was typical for all deep basins. Species-specific depth preferences and ranges result in statistically distinct communities at different depths with high within-depth similarity (60-80%). Differences were detectable between cruises in the epi- and mesopelagic layers (driven by the expatriates), but less so in the bathypelagic zone.

Long-distance island hopping without dispersal stages: transportation across major zoogeographic barriers in a Southern Ocean isopod

Species integrity is maintained only if recurrent allelic exchange between subpopulations occurs by means of migrating specimens. Predictions of this gene flow on the basis of observed or assumed mobility of marine species have proven to be error-prone. Using one mitochondrial gene and seven microsatellite markers, we studied the genetic structure and gene flow in Septemserolis septemcarinata, a strictly benthic species lacking pelagic larvae and the ability to swim. Suitable shallow-water habitats around three remote islands (South Georgia, Bouvet, and Marion Island) are geographically disjunct, isolated by more than 2,000 km of uninhabitable deep sea (east-west) and also separated by the Polar Front (north-south), which serves as a strong demarcation line in many marine taxa. Although we did find genetic differentiation among the three island populations, our results also revealed that a scenario with recent gene flow explains our data best. A model assuming no gene flow after initial colonization of the islands performs significantly worse. The tests also favor an asymmetric gene flow pattern (west to east >> east to west) thus mirroring the directionality of major oceanographic currents in the area. We conclude that rare long-distance dispersal rather than vicariance or human-mediated transport must be responsible for the observed patterns. As a mechanism, we propose passive rafting on floating substrata in the Antarctic Circumpolar Current. The results demonstrate that the effectiveness of a physical barrier is not solely a function of its physical parameters but strongly depends on how organisms interact with their environment.

Alien mollusks within the territory of Ukraine: Sources and directions of invasions

The main directions of expansion of alien mollusks in Ukraine are revealed. Expansions of both exotic species and nearby aliens ones are observed. The Danube, Dnieper, and line of water bodies of the Azov-Black Sea region’s seaside are important invasion corridors to the inland waters. The urbanization and reduction of zoogeographical barriers are the basic driving processes in expansion of alien terrestrial snails. Invasions into marine ecosystems are related to transfer of distant exotic species by sea navigation and homogenization of fauna in the East Mediterranean Basin (“pontization” and “mediterranization”).

Diversity and vertical distribution of mesozooplankton in the Arctic's Canada Basin

Abstract The composition and biomass of the zooplankton community within the Canada Basin down to 3000 m was studied during July 2005 at 12 stations. A total of 111 species including 74 species of crustaceans (55 species of copepods, 2 euphausiids, 11 amphipods, 1 decapod, 5 ostracods), 17 cnidarians (12 hydromedusae, 1 scyphomedusae, 4 siphonophora), 1 foraminifera, 4 ctenophores, 2 pteropods, 4 larvaceans, 4 chaetognaths, and 5 polychaetes were identified. Most of the species observed are typical of the Arctic waters, with the notable exception of several Pacific expatriate copepod species, suggesting no zoogeographical barrier between the Canadian and Eurasian basins. Overall species inventories appear unchanged over the past 50 years, and were similar to the Eurasian Basins. Zooplankton biomass averaged 3.6±0.23 g DW m −2 , with ∼50% of the biomass concentrated within the upper 100 m; nonetheless significant biomass and the majority of species diversity occurred below 100 m. Copepods represented 91% of the community numerically, followed by pteropods (2.6%), larvacean (1.8%) and shelled protists (1.5%), with other groups each contributing 1% or less. While copepods represented 85% of the total biomass, chaetognaths represented 13% on average (ca. 50% of non-copepod biomass), followed by cnidarians plus ctenophores (4.6%), ostracods (3.6%), and other groups (∼2% or less). Species-specific depth preferences and ranges resulted in statistically distinct communities in different depth strata and showed an orderly departure in similarity with increasing distance between strata. In Arctic waters, because temperature varies relatively little over the water column, so should respiratory rates; hence deep-water species are likely to play a greater role in the transfer or recycling of surface production than is typical of other deep ocean communities.

Distribution patterns of Chilean shallow-water sea anemones (Cnidaria: Anthozoa: Actiniaria, Corallimorpharia); with a discussion of the taxonomic and zoogeographic relationships between the actinofauna of the South East Pacific, the South West Atlantic and the Antarctic

The first complete zoogeographical analysis of Chilean shallow water sea anemones (Actiniaria and Corallimorpharia) and their taxonomic relations with neighbouring faunas is provided, based on extensive recent sampling in combination with a literature review. Between 1994 and 2004, we collected more than 1000 specimens of 32 distinct species of Actiniaria and Corallimorpharia at more than 100 sites along the Chilean coast between Arica (18°30’S; 70°19’W) and the Straits of Magellan (53°36’S 70°56’W). Sampling was done in the intertidal during low tides and in the subtidal by means of SCUBA diving down to depths of 40 m. The northern part of the Chilean fjord region showed the highest number of species (23). Our results contradict an abrupt general change in the marine faunal composition at 42°S, instead showing the continuation of species of the exposed coast and the joining of fjord species due to the availability of additional habitats in the richly structured fjord region south of 42°S, and also to eurybathy. The southern distribution limits of the species we found in northern and central Chile show only one significant concentration around the Peninsula Taitao (approx. 48°S). This either indicates a zoogeographic barrier for shallow water species at the Peninsula Taitao, or is a sampling artifact caused by poor data from the region between the Peninsula Taitao and the Straits of Magellan. According to the literature, 18 of the 63 described Chilean sea anemones (Pacific Ocean) can also be found in Argentina (Atlantic Ocean) and 13 in the Antarctic. However, many records and statuses of the common species of the South East Pacific and the South West Atlantic/Antarctic are uncertain or doubtful and need revision or confirmation.