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Article

Polyplacophoran Assemblages in Shallow Waters of the West Antarctic Peninsula: Patterns of Diversity, Composition and Abundance

by
Christian M. Ibáñez
1,*,
Sebastián Rosenfeld
2,3,4,
Ivka Carvajal
5,
Jennifer Catalán
5,6,
Germán Zapata-Hernández
7,
Manuel Gacitúa-Leible
5,
Rocio Vargas
5,
Pamela Morales
5,8,
Angie Díaz
3,9,
Sergio A. Carrasco
10,
Javier Sellanes
11,
Sadie Mills
12 and
María Cecilia Pardo-Gandarillas
5,*
1
One Health Institute, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago 8370251, Chile
2
Centro de Investigación Gaia Antártica, Universidad de Magallanes, Punta Arenas 6210427, Chile
3
Instituto Milenio Biodiversidad de Ecosistemas Antárticos y Subantárticos (MI-BASE), Santiago 7800003, Chile
4
Cape Horn International Center (CHIC), Puerto Williams 6350000, Chile
5
Departamento de Ecología y Biodiversidad, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago 8370251, Chile
6
Programa de Doctorado en Medicina de la Conservación, Universidad Andres Bello, Santiago 8370251, Chile
7
Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, National Institute of Marine Biology, Genoa Marine Center, 16149 Genova, Italy
8
Millennium Institute Center for Genome Regulation, Universidad de Chile, Santiago 8330111, Chile
9
Departamento de Zoología, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción 4070409, Chile
10
Departamento de Oceanografía, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción 4070409, Chile
11
Departamento de Biología Marina, Centro ESMOI, Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo 1781421, Chile
12
National Institute of Water & Atmospheric Research, Wellington 6241, New Zealand
 
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*
Authors to whom correspondence should be addressed.
Ecologies 2025, 6(1), 23; https://doi.org/10.3390/ecologies6010023
Submission received: 6 February 2025 / Revised: 7 March 2025 / Accepted: 8 March 2025 / Published: 10 March 2025
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Abstract

For the first time, field surveys for exploring the diversity and composition of shallow-water polyplacophorans in West Antarctica have been conducted. During the austral summer sampling campaigns of 2022, 2023 and 2024, a total of 1717 specimens of four species were collected from 21 localities. The composition, abundance, and diversity estimate of the assemblages showed that richness decreased southward due to changes in species composition. The ordination analysis showed a high similarity among localities. Thus, of the seven shallow-water chiton species previously recorded in Antarctica, only four were recorded here. Of them, Tonicina zschaui, Leptochiton kerguelensis, and Hemiarthrum setulosum were the most common and abundant, while Callochiton bouveti was the rarest and least abundant species. The diversity of shallow-water polyplacophorans in this area of Antarctica is low compared to the higher number of species reported in other sub-Antarctic regions. It is suggested that the effect of ice cover on shallow-water habitats could affect the abundance and diversity of chitons. In turn, the high similarity of assemblages may be due to the transport of larvae and juveniles by ocean currents and rafting between the studied sites.

1. Introduction

The Antarctic region is home to a diverse array of fauna, with an estimated over 8000 species of animals having been identified [1]. A significant proportion of these species, specifically 88%, are classified as benthic, and more than 50% of these species are endemic [1,2]. In the Southern Ocean, it has been documented that among a total of over 4000 benthic species, the most diverse groups are polychaetes, mollusks, and amphipods [2,3]. These benthic invertebrates, particularly deep-sea species, show a decline in species diversity with increasing latitude [4,5,6,7]. This pattern of diversity is clearly observed in the Antarctic deep sea, where the species richness of mollusks (gastropods and bivalves) increases with depth [8]. The hypothesis explaining this pattern is mainly related to the evolutionary success of some lineages that radiated in Antarctica [4], particularly benthic marine invertebrates that were able to persist in areas less impacted by ice expansion during glacial periods, such as deep-sea environments [9,10,11]. However, published reviews emphasize the need for further studies to fully understand the biogeographic patterns of benthic taxa in the Southern Ocean [4,7]. The question then arises as to whether the shallow taxa will show the same pattern of latitudinal species declines. Among mollusks, gastropods and bivalves are the dominant taxa in Antarctica; therefore, it is important to consider the implications for less diverse groups, such as polyplacophorans.
Among mollusks, the class Polyplacophora is a group of benthic marine invertebrates similar to limpets and commonly known as chitons, characterized by having eight overlapping plates on the dorsal surface to protect the soft parts of the animal [12,13]. Chitons contain approximately 1080 valid living species, and recent molecular phylogenetic analyses have confirmed four major clades: Lepidopleurida, Callochitonida, Acanthochitonina and Chitonina [13]. Most chitons inhabit hard substrates on shallow water habitats, and some species have been documented to live at bathyal, abyssal or even hadal depths, including seamounts and extreme habitats such as hydrothermal vents and methane seeps [13]. The abundance, composition, and species diversity of polyplacophoran species along the East Pacific coast exhibit a marked latitudinal gradient, shifting from tropical to cold ecosystems [14,15,16]. In this temperate ecosystem, the changes in species composition were predominantly influenced by smaller-scale variations in salinity and temperature [15].
In the Southern Ocean, the diversity and distribution of polyplacophorans include both shallow and deep-water species, from the intertidal zone to nearly 2000 m [17]. To date, a total of 10 chiton species have been described for the Southern Ocean, and most of them are eurybaths [1,17]. Nonetheless, there are also deep-water species, such as Leptochiton antarcticus, which range from 87 to 1524 m depth [18]. Interestingly, these Antarctic species are representatives of the four major clades within the class Polyplacophora, including: (i) genera endemic to the Southern Ocean (Leloupia, Hemiarthrum, Nuttallochiton, and Tonicina), and (ii) genera with widely distributed species (Leptochiton, Callochiton, Placiphorella). Indeed, over 60% of chiton species have a broad bathymetric and geographic distribution in the Southern Ocean, surrounding continental Antarctica [17]. It is also important to note that despite the presence of these species in Antarctica, polyplacophorans have been consistently underrepresented in ecological studies of shallow benthic assemblages over the last 30 years [19,20]. As a result, there is limited knowledge about their diversity, abundance, and distribution in Antarctic ecosystems. While they are known to live in association with rocks, boulders, sponges, and holdfasts of algae, and to be primary consumers [17], information on the ecology of chiton assemblages in Antarctica is still lacking. Therefore, an initial understanding of the diversity and spatial distribution of polyplacophorans across the Antarctic Peninsula is crucial to establish a framework for future ecological and biogeographic assessments of this group in polar environments.
The objective of this study is to provide a comprehensive description of the latitudinal changes in taxonomic composition, abundance, diversity, and dominance of shallow-water polyplacophoran assemblages on the western side of the Antarctic Peninsula, and to elucidate their relationships with environmental changes, offering insights into ecosystem dynamics in these rapidly changing polar environments.

2. Materials and Methods

During sampling campaigns conducted in the austral summer (January) of 2022, 2023, and 2024, chitons were collected from 21 localities distributed across the biogeographic province of Maritime Antarctica, over 900 km from north to south. This region encompasses the western side of the Antarctic Peninsula, situated north to 72 °S (see Figure 1). Chitons were collected during low tide (1–2 h), sampling two to four days per locality. The intertidal species were sampled by one to three people, while the subtidal species were sampled by two SCUBA divers (20–30 min) at depths up to 15 m. The collected species were relaxed in a solution of 5% ethanol with seawater, flattened, and then preserved in 96% ethanol for further analysis. The identification of chitons was conducted visually under a stereomicroscope, using the taxonomic monograph series of Kass & Van Belle [21,22].
To ensure consistency in the sampling effort, a relative abundance (RA) index was calculated following the methodology outlined by Ibáñez et al. [15]. This abundance is proportional to the number of chitons collected, corrected for sampling time and number of people (RA = number of chitons/hour/person). The RA data from the 21 localities were pooled into seven sectors, as follows: Wedell Sea (Vega Island, James Ross Island, Duroch Island, and Esperanza Bay); West Peninsula (Barrios Island, Estay Inlet, Kopaitik Island); King George Island (Becerra Inlet, Artigas Base, Ardley Isthmus, and Collins Glacier); Nelson Island (Nelson) and Greenwich Island (Orion Point, Cecilia Island, and Prat Base); Doumer Island (Biscoe Point, Yelcho Base, and George Point); Margarite Bay (Horseshoe Bay, Lagotellerie, and Carvajal Base). Species richness (S), iChao-1, diversity indices (Simpson, 1-D; Shannon, H’), and dominance (Simpson, D) were calculated for each sector using RA data in the statistical software PAST version 5.0.1 [23].
To explore latitudinal gradients in relative abundance (RA), species composition (Jaccard index), species richness (S), diversity indices (Simpson, 1-D; Shannon, H’), and dominance (Simpson, D), and their relationships with environmental changes, multivariate regression was applied. Multicollinearity between environmental variables was explored using the Variance Inflation Factor [24] (VIF). The environmental variables were surface data on temperature (°C), salinity (PSU), oxygen (mmol/m3), chlorophyll-a (mg/m3), ice thickness (m), and ice cover (fraction) obtained from the Bio-Oracle database [25] via QGIS software version 3.40 (http://www.qgis.org).
Ecologies 06 00023 g001
Figure 1. Collection sites in Antarctica. Bahía Herradura (BH), Carvajal Base (BC), Lagotellerie (LT), George Point (GP), Biscoe Point (BP), Yelcho Station (YE), Duroch Island (ID), Vega Island (IV), Esperanza Bay (ES), Artigas Station (AR), Becerra Islet (BE), Barrios Island (IB), Estay Islet (IE), Orion Point (PO), Cecilia Island (IC), Prat Base (PT), Kopaitik (KO), Nelson Island (NE), Ardley Isthmus (IA), Collins Glacier (CO). Marine currents modified from [26]. ACC: Antarctic Circumpolar Current, APCC: Antarctic Peninsula Coastal Current.
Figure 1. Collection sites in Antarctica. Bahía Herradura (BH), Carvajal Base (BC), Lagotellerie (LT), George Point (GP), Biscoe Point (BP), Yelcho Station (YE), Duroch Island (ID), Vega Island (IV), Esperanza Bay (ES), Artigas Station (AR), Becerra Islet (BE), Barrios Island (IB), Estay Islet (IE), Orion Point (PO), Cecilia Island (IC), Prat Base (PT), Kopaitik (KO), Nelson Island (NE), Ardley Isthmus (IA), Collins Glacier (CO). Marine currents modified from [26]. ACC: Antarctic Circumpolar Current, APCC: Antarctic Peninsula Coastal Current.
Ecologies 06 00023 g001
Non-metric multidimensional scaling (nMDS) [27] analysis was performed using the Bray–Curtis index to visualize the similarity of chiton assemblages among sectors. The Bray–Curtis similarity among sectors was assessed using a one-way permutational multivariate analysis of variance (PERMANOVA), using 10,000 permutations [28].
Hierarchical cluster analysis using the UPGMA algorithm was employed to compare species composition among sectors using the Jaccard index [23]. The node support was assessed by a bootstrap procedure with 1000 replicates. The Jaccard composition among sectors was assessed using a one-way PERMANOVA, using 10,000 permutations [28]. All analyses were performed in statistical software PAST version 5.0.1 [23].

3. Results

A total of 1717 chiton specimens belonging to four species previously recorded for the western side of the Antarctic Peninsula were obtained. The most frequently found species were Tonicina zschaui (69.6%) (Figure 2A), followed by Leptochiton kerguelensis (15.5%) (Figure 2D) and Hemiarthrum setulosum (14.8%) (Figure 2B), while the less frequent species was Callochiton bouveti (0.1%) (Figure 2C) (Table 1). Tonicina zschaui was the species with the highest relative abundance index and was found in all sectors, which contrasts with the other species (Table 1).
Nelson and Greenwich Islands showed the lowest relative abundance and diversity indices, with two or three species, and therefore the sectors with the highest dominance (>0.75) (Table 2). Meanwhile, the King George Island and West Peninsula assemblages recorded the highest relative abundance and diversity indices, composed of four and three species, but were the sectors with the lowest dominance (Table 2). Overall, species composition, species richness, diversity indices, and dominance showed a significant trend toward higher latitudes (p < 0.05, Table 3), reducing from four to two species, due to taxonomic turnover and local dominance of some taxa (Table 1 and Table 2). The best fit was species richness with latitude (R2 = 0.39, Table 3). Environmental variables did not show significant correlations with species composition, species richness, diversity indices, and dominance (p > 0.1, Table 3). Multicollinearity between environmental variables was not an issue according to the Variance Inflation Factor (VIF < 2.0).
Non-metric Multidimensional scaling analysis showed an overlap in similarity (Stress = 0.3658) among the Nelson, Greenwich, Weddell, King George Island, West Peninsula, and Doumer Island sectors (Figure 3), while Margarita showed greater similarity with West Peninsula. King George Island showed the bigger convex hull area, since two localities (Collins Glacier (CO) and Ardley Isthmus (IA)) were further apart in the ordination due to the dominance of H. setulosum (Figure 3, Table 1). Doumer Island evidenced a long triangle convex hull shape due to the low abundance and diversity of chitons in Biscoe Point (BP) and Geoge Point (GP) localities due to the dominance of T. zschaui (Figure 3, Table 1). This high similarity between chiton assemblages was further supported by the results of the PERMANOVA analysis, which showed no significant differences between sectors (F(6, 14) = 1.556, p = 0.0988).
Cluster analysis revealed three distinct groups. Two of these groups exhibited a high similarity in species composition: 1. One group comprised Doumer Island and Margarite Bay, with Jaccard similarity index > 0.95; and 2. another group consisted of King George Island, Weddell Sea, West Peninsula, and Greenwich Island (Jaccard index > 0.75, Figure 4). Both groups were supported by high bootstrap values (>50). The third group corresponding to Nelson Island was separated from these two, with a different species composition, which was evidenced by a lower similarity (<0.4) (Figure 4). The most abundant chiton species, T. zschaui and L. kerguelensis, showed a high similarity (Figure 4) compared with the other two species, since both were present in all sectors sampled. Significant differences were observed in the species composition of shallow polyplacophoran assemblages, as was determined by Jaccard (PERMANOVA, F(6, 14) = 2.736, p = 0.0224), partly due to the absence of H. setulosum and C. bouveti in the southernmost sectors of the Antarctic Peninsula (Doumer Island and Margarite Bay, Table 1). Pairwise comparison analyses also indicate significant differences in species composition between King George Island and Doumer Island (p = 0.0291) and between King George Island and Margarite Bay (p = 0.0299).

4. Discussion

Shallow-water polyplacophoran assemblages on the western side of the Antarctic Peninsula showed low diversity compared to the number of species reported for other subantarctic and cold-water regions [14,29,30]. Chiton species composition and richness decreased significantly towards a higher latitude, as has been observed in other molluscan species in Antarctica [4,6,7]. Therefore, this latitudinal pattern of chitons supports that shallow-water species in Antarctica respond to the classical diversity gradient reported in several marine taxa worldwide [31].
The low abundance and diversity of shallow-water chitons on the western Antarctic Peninsula may be a result of habitat reduction by coastal ice formation, which is the most common physical disturbance on the Antarctic coast [32]. These ice sheets along the coast reach a depth of approximately 10 m, which reduces the number of suitable habitats in the intertidal and subtidal zones, effects that are most pronounced during winter, when the ice sheets reach approximately 30 m in depth [33]. For instance, such disturbances are responsible for vertical zonation of the shallow Antarctic benthic fauna [34,35] and the diversity of seaweeds along the Peninsula [36]. In this study, during summer, chitons were not found in intertidal zones where ice sheet persisted, but they were found in the same locality, in subtidal habitats, where the ice does not reach a greater depth (Margarita Bay, Doumer Island). Another factor that would explain the low diversity of chitons is the reduction in the dietary supply, for example, the decrease in the abundance and diversity of seaweed towards the south of the peninsula [36]. This factor, added to the physical loss of habitats, could also be relevant in shaping the diversity of Antarctic polyplacophoran assemblages, as has been evidenced in temperate and tropical ecosystems [37]. In fact, in tropical and temperate rocky ecosystems with high diversity and abundance of marine algae, up to 12 species of chitons have been identified [15,29,37,38,39,40].
The chiton species identified in this study exhibit a wide geographic distribution in the Southern Ocean [17]. Leptochiton kerguelensis, H. setulosum, C. bouveti, and T. zschaui are reported to inhabit the Subantarctic Islands and Magellan region [21,22]. However, the presence of T. zschaui in the Magellan region (Argentina/Chile) is still doubtful because Schwabe et al. [17] cited Castellanos [41] as a record in Magallanes. However, this publication does not record T. zschaui in the Magellan region, but in the Antarctic Peninsula and South Georgia Islands. Furthermore, Sirenko [29] did not record this species in his samplings carried out in the Falkland Islands, Strait of Magellan, Beagle Channel or Isla de los Estados. Finally, during several sampling expeditions in the Beagle Channel and the Strait of Magellan carried out by one of the researchers of this study (S. Rosenfeld, personal communication), this species was not found in that region either, so we suggest that T. zschaui could be an endemic species of the Southern Ocean.
The high similarity found among assemblages of different sectors (Figure 3) may occur since the pelagic larvae of the species T. zchaui and C. bouveti can be dispersed by the marine currents between the peninsula and the South Shetland Islands [42,43]. On the other hand, H. setulosum and L. kerguelensis brood their embryos [44], so the dispersal potential is much more limited. However, adult chitons have been found at distant sites, suggesting that transport may occur on seaweed or other floating objects, as reported for H. setulosum and other chiton species [45,46]. The process of transporting various organisms on algae (rafting) plays a key role in the long-distance dispersal of marine organisms, particularly in the Southern Hemisphere [47]. This mechanism explains the widespread but disjunct distributions of numerous coastal species with limited dispersal capabilities [46]. For example, the phylogeographic pattern of the direct developer Antarctic gastropod Laevilacunaria antarctica shows historical connectivity along the entire Antarctic Peninsula, demonstrating that rafting can be a very important mechanism for maintaining connectivity along the Antarctic Peninsula [48]. These findings could highlight the importance of algal transport in shaping marine biogeography and maintaining genetic connectivity between isolated populations across the Southern Ocean.
Finally, surveys addressing the diversity of intertidal polyplacophorans should be extended to other regions of the Antarctic continent to fully understand the biodiversity patterns and life history strategies of this important group, as well as for other poorly studied marine invertebrates around the Southern Ocean.

Author Contributions

Conceptualization, C.M.I. and M.C.P.-G.; methodology, C.M.I., G.Z.-H., A.D., S.R. and M.C.P.-G.; formal analysis, C.M.I., J.C.; data curation, J.C., I.C., M.G.-L. and R.V.; writing—original draft preparation, C.M.I.; project administration, C.M.I. and M.C.P.-G.; funding acquisition, C.M.I., J.S., P.M., S.A.C., A.D., S.M. and M.C.P.-G. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by Instituto Antártico Chileno (INACH), funding number RT 07-20. Additionally, this research was funded by Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT), funding number FONDECYT 1241863, by Agencia Nacional de Investigación y Desarrollo de Chile (ANID), funding number Anillo ANID ATE 220044, and by ANID Millennium Science Initiative Program, funding number ICN2021_002.

Institutional Review Board Statement

The study was conducted following the Ethics Committee of Universidad Andres Bello.

Informed Consent Statement

Not applicable.

Data Availability Statement

All data from this study are available upon request from authors.

Acknowledgments

We thank the RV Betanzos crew and INACH staff for their logistical support on all Antarctic scientific expeditions (ECA58, ECA59, and ECA60). Special thanks to Rodrigo Bermeo from Hippocampus Diving Center.

Conflicts of Interest

The authors declare no conflicts of interest.

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Figure 2. Pictures of chiton species collected in West Antarctica. (A) Tonicina zschaui, Nelson Island (scale 2 mm); (B) Hemiarthrum setulosum, Ardley Isthmus (scale 2 mm); (C) Callochiton bouveti, Nelson Island (scale 10 mm); (D) Leptochiton kerguelensis, Kopaitik Island (scale 1 mm).
Figure 2. Pictures of chiton species collected in West Antarctica. (A) Tonicina zschaui, Nelson Island (scale 2 mm); (B) Hemiarthrum setulosum, Ardley Isthmus (scale 2 mm); (C) Callochiton bouveti, Nelson Island (scale 10 mm); (D) Leptochiton kerguelensis, Kopaitik Island (scale 1 mm).
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Figure 3. Non-metric multidimensional Scaling (nMDS) analysis based on the relative abundances of Antarctic chitons grouped into seven sectors: Wedell Sea (Wedell), West Peninsula (Peninsula), King George Island (King George), Nelson Island (Nelson), Greenwich Island (Greenwich), Doumer Island (Doumer) and Margarita Bay (Margarita).
Figure 3. Non-metric multidimensional Scaling (nMDS) analysis based on the relative abundances of Antarctic chitons grouped into seven sectors: Wedell Sea (Wedell), West Peninsula (Peninsula), King George Island (King George), Nelson Island (Nelson), Greenwich Island (Greenwich), Doumer Island (Doumer) and Margarita Bay (Margarita).
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Figure 4. Hierarchical cluster analysis based on the species composition of Antarctic chitons among sectors.
Figure 4. Hierarchical cluster analysis based on the species composition of Antarctic chitons among sectors.
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Table 1. Relative abundance index (chitons/hour/person) of polyplacophoran species in West Antarctica.
Table 1. Relative abundance index (chitons/hour/person) of polyplacophoran species in West Antarctica.
LocalitiesTonicina zschauiHemiarthum setulosumLeptochiton kerguelensisCallochiton bouvetiTotal
Weddell Sea46.252.250.500.2549.25
West Peninsula62.2540.5035.50 138.25
King George Island29.7530.3817.630.2578.00
Nelson Island11.75 0.2512.00
Greenwich Island33.752.752.13 38.63
Doumer Island90.25 10.00 100.25
Margarite Bay84.00 14.00 98.00
Total358.0075.8879.750.75514.38
Table 2. Diversity indices of polyplacophoran assemblages in West Antarctica.
Table 2. Diversity indices of polyplacophoran assemblages in West Antarctica.
LocalitiesRichnessiChao1AbundanceDominanceSimpsonShannon
Weddell Sea4449.250.88170.11830.3039
West Peninsula33138.250.34980.65021.075
King George Island4478.000.33970.66031.109
Nelson Island2212.000.95550.04450.1429
Greenwich Island3338.630.76550.23450.4915
Doumer Island22100.250.81860.18140.3295
Margarite Bay2298.000.75260.24740.4152
Table 3. Multivariate regression among diversity indices of polyplacophoran assemblages in West Antarctica and environmental variables.
Table 3. Multivariate regression among diversity indices of polyplacophoran assemblages in West Antarctica and environmental variables.
CompositionCoefficientS.E.t-Valuep-ValueR2VIF
Latitude0.06800.02732.48700.02720.23721.3110
Temperature−0.09950.1955−0.50910.61920.01691.0172
Salinity−0.06720.1517−0.44260.66530.04041.0421
Oxygen0.01230.00901.37100.19360.03421.0354
Chlorophyll-a−0.16350.1899−0.86100.40480.04681.0491
Ice thicknes−1.57791.6731−0.94310.36280.05101.0537
Ice cover0.86762.27190.38190.70870.03421.0354
SPECIES RICHNESS
Latitude−0.40470.1085−3.72930.00250.39941.6649
Temperature0.36750.77620.47340.64380.00811.0082
Salinity−0.02690.6024−0.04470.96500.11461.1294
Oxygen−0.04750.0357−1.33100.20610.01191.0121
Chlorophyll-a0.62200.75380.82520.42420.00121.0012
Ice thicknes3.66896.64270.55230.59010.11831.1341
Ice cover−2.54719.0204−0.28240.78210.09711.1076
ABUNDANCE
Latitude−1.27624.2203−0.30240.76710.05441.0575
Temperature18.132030.19100.60060.55840.05391.0569
Salinity−5.033923.4320−0.21480.83320.00091.0009
Oxygen−0.92391.3870−0.66610.51700.12041.1369
Chlorophyll-a31.797029.31901.08450.29780.16631.1994
Ice thicknes107.9300258.37000.41770.68300.01001.0101
Ice cover−224.6300350.8500−0.64030.53310.00051.0005
DOMINANCE
Latitude0.07090.03262.17870.04840.04311.0451
Temperature−0.12340.2329−0.53000.60510.05731.0608
Salinity0.06650.18080.36790.71890.04391.0459
Oxygen0.00080.01070.07910.93820.02491.0255
Chlorophyll-a−0.28670.2262−1.26750.22720.10791.1210
Ice thicknes−0.18511.9933−0.09280.92750.02151.0220
Ice cover1.07372.70680.39670.69800.04301.0449
SIMPSON INDEX
Latitude−0.07090.0326−2.17860.04840.04311.0451
Temperature0.12340.23290.52990.60510.05731.0608
Salinity−0.06650.1808−0.36790.71890.04391.0459
Oxygen−0.00080.0107−0.07910.93820.02491.0255
Chlorophyll-a0.28670.22621.26750.22720.10791.1210
Ice thicknes0.18511.99330.09280.92740.02151.0220
Ice cover−1.07372.7068−0.39670.69800.04301.0449
SHANNON INDEX
Latitude−0.13490.0488−2.76290.01610.108321.1215
Temperature0.21690.34930.62110.54530.056441.0598
Salinity−0.11650.2711−0.42970.67450.050731.0534
Oxygen−0.00030.0160−0.01620.98730.013651.0138
Chlorophyll-a0.49150.33921.44890.17110.071571.0771
Ice thicknes0.72752.98920.24340.81150.031691.0327
Ice cover−2.35994.0592−0.58140.57090.045161.0473
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Ibáñez, C.M.; Rosenfeld, S.; Carvajal, I.; Catalán, J.; Zapata-Hernández, G.; Gacitúa-Leible, M.; Vargas, R.; Morales, P.; Díaz, A.; Carrasco, S.A.; et al. Polyplacophoran Assemblages in Shallow Waters of the West Antarctic Peninsula: Patterns of Diversity, Composition and Abundance. Ecologies 2025, 6, 23. https://doi.org/10.3390/ecologies6010023

AMA Style

Ibáñez CM, Rosenfeld S, Carvajal I, Catalán J, Zapata-Hernández G, Gacitúa-Leible M, Vargas R, Morales P, Díaz A, Carrasco SA, et al. Polyplacophoran Assemblages in Shallow Waters of the West Antarctic Peninsula: Patterns of Diversity, Composition and Abundance. Ecologies. 2025; 6(1):23. https://doi.org/10.3390/ecologies6010023

Chicago/Turabian Style

Ibáñez, Christian M., Sebastián Rosenfeld, Ivka Carvajal, Jennifer Catalán, Germán Zapata-Hernández, Manuel Gacitúa-Leible, Rocio Vargas, Pamela Morales, Angie Díaz, Sergio A. Carrasco, and et al. 2025. "Polyplacophoran Assemblages in Shallow Waters of the West Antarctic Peninsula: Patterns of Diversity, Composition and Abundance" Ecologies 6, no. 1: 23. https://doi.org/10.3390/ecologies6010023

APA Style

Ibáñez, C. M., Rosenfeld, S., Carvajal, I., Catalán, J., Zapata-Hernández, G., Gacitúa-Leible, M., Vargas, R., Morales, P., Díaz, A., Carrasco, S. A., Sellanes, J., Mills, S., & Pardo-Gandarillas, M. C. (2025). Polyplacophoran Assemblages in Shallow Waters of the West Antarctic Peninsula: Patterns of Diversity, Composition and Abundance. Ecologies, 6(1), 23. https://doi.org/10.3390/ecologies6010023

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