Land Crab Research Articles

Mitogenome selection shaped the terrestrial adaptation of Grapsidae (Decapoda: Brachyura)

The colonization of aquatic to terrestrial habitats by brachyuran crabs requires genetic innovations as well as morphological adaptations to adapt to terrestrial environments. The genetic basis of such adaptive evolution, however, is largely unknown. This study focuses on terrestrialization in Geograpsus (Grapsidae) the only highly terrestrial genus in this family, which represents a notable example of terrestrial adaptive radiation. Here, we sequenced the mitogenomes of two Geograpsus species and used the mitogenomes of 215 representative crabs to construct phylogenetic and time frameworks that we used to infer terrestrial origins and evolution. Using mitochondrial genomic data, we demonstrated that marine crab ancestors began to settle on land during the early Eocene. Ocean acidification, the Paleocene-Eocene Thermal Maximum (PETM), and mangrove expansion at that time may have driven the diversification and ecological expansion of these terrestrial crabs. Evolutionary analyses reveal strong positive selection signals on monophyletic lineages of Grapsidae, especially the terrestrial species of Geograpsus. Positively selected sites in functionally important regions of ND5 and ND4 may imply enhanced energy metabolism in Grapsidae compared to other crabs, and may have played an important role in their terrestrial adaptation. Overall, our work provides valuable resources and opportunities to reveal the adaptation of crabs to complex terrestrial environments.

Effects of molting on the expression of ecdysteroid responsive genes in the crustacean molting gland (Y-organ)

Ecdysteroid molting hormones coordinate arthropod growth and development. Binding of 20-hydroxyecdysone (20E) to ecdysteroid receptor EcR/RXR activates a cascade of nuclear receptor transcription factors that mediate tissue responses to hormone. Insect ecdysteroid responsive and Forkhead box class O (FOXO) transcription factor gene sequences were used to extract orthologs from blackback land crab (Gecarcinus lateralis) Y-organ (YO) transcriptome: Gl-Ecdysone Receptor (EcR), Gl-Broad Complex (Br-C), Gl-E74, Gl-Hormone Receptor 3 (HR3), Gl-Hormone Receptor 4 (HR4), Gl-FOXO, and Gl-Fushi tarazu factor-1 (Ftz-f1). Quantitative polymerase chain reaction quantified mRNA levels in tissues from intermolt animals and in YO of animals induced to molt by multiple limb autotomy (MLA) or eyestalk ablation (ESA). Gl-EcR, Gl-Retinoid X Receptor (RXR), Gl-Br-C, Gl-HR3, Gl-HR4, Gl-E74, Gl-E75, Gl-Ftz-f1, and Gl-FOXO were expressed in all 10 tissues, with Gl-Br-C, Gl-E74, Gl-E75, and Gl-HR4 mRNA levels in the YO lower than those in most of the other tissues. In MLA animals, molting had no effect on Gl-Br-C, Gl-E74, and Gl-Ftz-f1 mRNA levels and little effect on Gl-EcR, Gl-E75, and Gl-HR4 mRNA levels. Gl-HR3 and Gl-FOXO mRNA levels were increased during premolt stages, while Gl-RXR mRNA level was highest during intermolt and premolt stages and lowest at postmolt stage. In ESA animals, YO mRNA levels were not correlated with hemolymph ecdysteroid titers. ESA had no effect on Gl-EcR, Gl-E74, Gl-HR3, Gl-HR4, Gl-Ftz-f1, and Gl-FOXO mRNA levels, while Gl-RXR, Gl-Br-C, and Gl-E75 mRNA levels were decreased at 3 days post-ESA. These data suggest that transcriptional up-regulation of Gl-FOXO and Gl-HR3 contributes to increased YO ecdysteroidogenesis during premolt. By contrast, transcriptional regulation of ecdysteroid responsive genes and ecdysteroidogenesis were uncoupled in the YO of ESA animals.

Is the threatened land crab Cardisoma guanhumi conquering human-dominated systems?

Land use changes are heralded as a major driver of biodiversity loss. However, recent findings show that cities, perhaps the most radical habitat transformation, sustain increasing numbers of threatened species. This emerging trend has been mostly chronicled for vertebrates from landlocked cities, although loss of biodiversity and rates or urbanization are higher in coastal marine systems. To advance our understanding on how threatened species may conquer human-dominated systems, we studied the threatened edible crab Cardisoma guanhumi and assessed how it is proliferating in croplands and urban systems at different spatial scales and whether populations show consequences of long-term exploitation. We gathered the data on crab populations covering the whole distribution range, including three countries reporting this as a threatened species. The abundance, distribution, and size structure of crab populations among different land uses at local scales were compared and published data for populations thriving in different habitats throughout their distribution range were compiled. We found that at local scale this species is able to thrive in natural and human-disturbed habitats, where food sources are heavily altered. At larger scales, the species showed no differences in abundance and size structure among natural and anthropogenic habitats. In areas near the southern distribution edge, crab populations were more abundant and composed of larger animals in urban areas and croplands than those in natural habitats, suggesting that human-disturbed systems are stepping stones to extend the geographic range. However, we found a long-term reduction in maximum body size, exacerbated by land use changes, that likely reflects exploitation regimes consistently targeting larger crabs. Despite its status as a threatened species, the long history of human exploitation combined with livestock farming practices may explain the proliferation of this crab in human-dominated systems, which emphasize the need to consider conservation in human-dominated systems.

In silico analysis of crustacean hyperglycemic hormone family G protein-coupled receptor candidates.

Ecdysteroid molting hormone synthesis is directed by a pair of molting glands or Y-organs (YOs), and this synthesis is inhibited by molt-inhibiting hormone (MIH). MIH is a member of the crustacean hyperglycemic hormone (CHH) neuropeptide superfamily, which includes CHH and insect ion transport peptide (ITP). It is hypothesized that the MIH receptor is a Class A (Rhodopsin-like) G protein-coupled receptor (GPCR). The YO of the blackback land crab, Gecarcinus lateralis, expresses 49 Class A GPCRs, three of which (Gl-CHHR-A9, -A10, and -A12) were provisionally assigned as CHH-like receptors. CrusTome, a transcriptome database assembled from 189 crustaceans and 12 ecdysozoan outgroups, was used to deorphanize candidate MIH/CHH GPCRs, relying on sequence homology to three functionally characterized ITP receptors (BNGR-A2, BNGR-A24, and BNGR-A34) in the silk moth, Bombyx mori. Phylogenetic analysis and multiple sequence alignments across major taxonomic groups revealed extensive expansion and diversification of crustacean A2, A24, and A34 receptors, designated CHH Family Receptor Candidates (CFRCs). The A2 clade was divided into three subclades; A24 clade was divided into five subclades; and A34 was divided into six subclades. The subclades were distinguished by conserved motifs in extracellular loop (ECL) 2 and ECL3 in the ligand-binding region. Eleven of the 14 subclades occurred in decapod crustaceans. In G. lateralis, seven CFRC sequences, designated Gl-CFRC-A2α1, -A24α, -A24β1, -A24β2, -A34α2, -A34β1, and -A34β2, were identified; the three A34 sequences corresponded to Gl-GPCR-A12, -A9, and A10, respectively. ECL2 in all the CFRC sequences had a two-stranded β-sheet structure similar to human Class A GPCRs, whereas the ECL2 of decapod CFRC-A34β1/β2 had an additional two-stranded β-sheet. We hypothesize that this second β-sheet on ECL2 plays a role in MIH/CHH binding and activation, which will be investigated further with functional assays.

Ionic regulatory strategies of crabs: the transition from water to land.

Terrestrial crabs (brachyurans and anomurans) have invaded land following a variety of pathways from marine and/or via freshwater environments. This transition from water to land requires physiological, ecological, and behavioral adaptations to allow the exploitation of these new environmental conditions. Arguably, the management of salt and water balance (e.g., osmoregulation) is integral for their survival and success in an environment where predominantly low-salinity aquatic (e.g., freshwater) water sources are found, sometimes in only minimal amounts. This requires a suite of morphological and biochemical modifications, especially at the branchial chamber of semi-terrestrial and terrestrial crabs to allow reprocessing of urine to maximize ion uptake. Using knowledge gained from electrophysiology, biochemistry, and more recent molecular biology techniques, we present summarized updated models for ion transport for all major taxonomic groups of terrestrial crabs. This is an exciting and fast-moving field of research, and we hope that this review will stimulate further study. Terrestrial crabs retain their crown as the ideal model group for studying the evolutionary pathways that facilitated terrestrial invasion.

Beneath the surface: co-habitation of recruits of the land crab Johngarthia lagostoma and its relevance for conservation on oceanic islands

Abstract Gecarcinid crabs have their life cycles in antagonistic scenarios, with their larvae developing in the sea and the juvenile/adult phases occurring on land. Adults migrate from land to sea to release their larvae, which return to land upon reaching the megalopa stage. Recruitment and early instar traits in gecarcinids crabs remain unknown, leading to some species lacking age-specific information. Despite massive recruitment observed in some insular gecarcinid species (e.g. Gecarcoidea natalis), recruits are generally expected to be few and exhibit cryptic behaviour, potentially occupying the burrows of conspecifics. We evaluated whether recruits of Johngarthia lagostoma on Trindade Island, Brazil, co-inhabit larger conspecific burrows, analysing this occurrence and examining their growth patterns, density, and body size across different lunar phases. Johngarthia lagostoma recruits inhabit conspecific burrows, either abandoned or occupied by adult crabs, but always with leaves stored in the inner chamber. Recruits in co-inhabiting behaviour reach a maximum carapace width of 7.3 mm, and after that, they are likely detected by the adults and possibly cannibalized or leave burrows naturally. During the full moon, the higher density and smaller size of recruits were recorded, indicating a recruitment lunar phase. It is crucial to ascertain the prevalence of co-inhabitation behaviours in other land crab species to expand the knowledge about recruitment patterns in these key community species.

Holocene Crab Consumption at Watinglo, Papua New Guinea

Malacostraca are commonly found in coastal archaeological sites in the Indo-Pacific; both swimming and terrestrial crabs. This archaeological evidence as well as ethnographic studies indicate that they formed an important component of the human diet in the past as they still do in many regions today. However, they often go unidentified and largely unanalysed in archaeological research due to the highly fragmentary state of the remains and the associated difficulties posed for identification and quantification. Here we discuss these issues and provide an example of crab remains recovered from a coastal archaeological site in Papua New Guinea, Watinglo shelter, with an occupation record spanning from the Terminal Pleistocene to historic times. We also briefly compare these finding to crab remains from archaeological sites of similar antiquity in Indonesia and the Philippines.

Histopatological Impact of Malathion on the Reproductive Organs of Freshwater Crabs Barytelhusa Cunicularis (Westwood, 1836)

Crabs are particularly useful in aquatic environment and play a very important role in the ecosystem processes and good indicator for polluted condition. The terrestrial crab plays a significant modal in the study of population and also beneficial for human activities. The present study deals with the histochemical changes of organophosphate, malathion in the freshwater crab Barytelphusa cunicularis. Live specimens of Barytelphusa cunicularis were collected from local wet areas of Marodasector, Bhilai, (C.G). The crabs were sexed on the basis of the shape of the abdomen. Average weight of crabs varies from (45-50 gms), the carapace length and carapace width varies from 3.20-4.50mm and 4.25-5.80mm respectively. The crabs were acclimatized in the laboratory condition, and kept in two groups the control group set free from Malathion and the experimental group was exposed to malathion for LC50 at different concentration 0.45ppm, 0.30ppm, 0.26ppm and 0.25ppm for 24hrs, 48hrs, 72hrs and 96hrs respectively. The sections of 5µm were taken for the histopathological examination of testis and ovary; affected due to the impact of Malathion, the testicular follicular cells interstitials cells and nutritive cells were decreased and distracted number of sperm cells it exhibited irregular arrangement of nucleus, in the ovary epithelial layer destruction, degeneration of oocytes, Shrinkage in ooplasm, vacuolization and reduction in cytoplasmic material. The result suggests that rapid utilization to meet the energy demands under the impact of malathion.

Species-specific gill’s microbiome of eight crab species with different breathing adaptations

Transitions to physically different environments, such as the water-to-land transition, proved to be the main drivers of relevant evolutionary events. Brachyuran crabs evolved remarkable morphological, behavioral, and physiological adaptations to terrestrial life. Terrestrial species evolved new respiratory structures devoted to replace or support the gills, a multifunctional organ devoted to gas exchanges, ion-regulation and nitrogen excretion. It was hypothesized that microorganisms associated with respiratory apparatus could have facilitated the processes of osmoregulation, respiration, and elimination of metabolites along this evolutionary transition. To test if crab species with different breathing adaptations may host similar microbial communities on their gills, we performed a comparative targeted-metagenomic analysis, selecting two marine and six terrestrial crabs belonging to different families and characterised by different breathing adaptations. We analysed anterior and posterior gills separately according to their different and specific roles. Regardless of their terrestrial or marine adaptations, microbial assemblages were strongly species-specific indicating a non-random association between the host and its microbiome. Significant differences were found in only two terrestrial species when considering posterior vs. anterior gills, without any association with species-specific respiratory adaptations. Our results suggest that all the selected species are strongly adapted to the ecological niche and specific micro-habitat they colonise.

Using Public Sightings to Document the Widespread Distribution of the Non-Endemic Blue Land Crab, Cardisoma guanhumi, in South Carolina

Using Public Sightings to Document the Widespread Distribution of the Non-Endemic Blue Land Crab, Cardisoma guanhumi, in South Carolina

Description of a Highly Modified Endemic Ground Beetle (Coleoptera, Carabidae) from the Oceanic Island of Malpelo, Colombia

The oceanic island of Malpelo, 380 km west of the Colombian mainland, stands out from other islands of the Tropical Eastern Pacific by its harsh environment and depauperate flora and fauna, thus imposing strong selective pressure on the small number of invertebrates that inhabit it. The endemic taxon described here, Dyscolus (Cacothrix) malpelensis, n. subgen., n. sp. (Carabidae, Platynini), is a remarkable example of adaptation to this unique ecosystem. The modifications of its body shape, including a tight coaptation of elytra and pronotum, might be a response to strong environmental constraints, from predation by lizards and land crabs to the absence of deep soil that forces the beetle to seek shelter in caves and rock crevices.

The diversity and distribution of Gecarcinidae MacLeay, 1838 (Crustacea: Decapoda: Brachyura), a potential land crab as a valuable food resource, in Indonesia

Gecarcinidae is one of the land crabs that is commonly found in intertidal and coastal areas comprises of 28 species worldwide. On some regions, this crab has been known as one of food resources. However, Indonesians have no interest yet in consuming this potentially high-value species. The present study aims to reveal the diversity and distribution of Gecarcinidae in Indonesia and discuss its potencies. Specimens of Gecarcinidae deposited in Museum Zoologicum Bogoriense (MZB) were used for observation and their morphological differences were recorded. Their recorded localities were used to define the hypothetical distribution. Their economic potential assessments were based on some literatures. In total, there are five species recorded in Indonesia, i.e., Cardisoma carnifex, Gecarcoidea humei, Gecarcoidea lalandii Tuerkayana hirtipes, and Tuerkayana magnum. The widest-distributed species are Cardisoma carnifex and Tuerkayana hirtipes. Among these species, the two largest species are Cardisoma carnifex and Tuerkayana magnum. In Pacific regions, Gecarcoidea is harvested as one of food resources. Therefore, these five species have high potency to support food sustainability and revealing the potencies and chance for captivity could serve as a catalyst to elevate community welfare, especially in coastal areas. Conservation on the natural habitat is necessary to maintain the sustainable utilization.

Intraspecific color diversity and camouflage associated with ontogeny in an insular land crab

Intraspecific color diversity and camouflage associated with ontogeny in an insular land crab

The Pathogenic Yeast Metschnikowia bicuspidata var. bicuspidata in the Aquacultured Ecosystem and Its Biocontrol.

M. bicuspidata var. bicuspidata is a pathogenic yeast which can affect aquacultured and marine-cultured animals such as brine shrimp, ridgetail white prawn, chinook salmon, giant freshwater prawn, the Chinese mitten crab, marine crab, the mud crab, the mangrove land crab, the Chinese grass shrimp, sea urchins, sea urchins, Daphnia dentifera and even snails, causing a milky disease, and it has caused big economic losses in aquacultural and marine-cultural industries in the past. However, the detailed mechanisms and the reasons for the milky disease in the diseased aquatic animals are still completely unknown. So far, only some antimycotics, killer toxins and Massoia lactone haven been found to be able to actively control and kill its growth. The ecofriendly, green and renewable killer toxins and Massoia lactone have high potential for application in controlling the milky disease.

“Capture with a camera!” A non-contact method for obtaining the body size data from ovigerous female land crabs during breeding migration

Abstract Body size is a crucial metric that is often obtained during the breeding migration of female land crabs. Most commonly, these measurements are obtained by hand but hand-measuring them carries risks for both crabs and researchers. In this study, we developed a novel “photo-image approach” to measure the maximum carapace width of Cardisoma carnifex (Herbst, 1796) in the field, and compared the results with hand measurements. We found a significant relationship in the maximum carapace width measured between the two approaches (Linear regression, , ). The difference (0.54 ± 0.18 mm) and relative error (0.61 ± 0.19%) in the maximum carapace width measured between the two approaches were minimal. We suggest that the photo-image approach is feasible for determining crab size in the field. The approach holds promise for its application in citizen science projects, facilitating advancements in crab research.

Variation and taphonomic implications of composition in modern and fossil malacostracan cuticles (Decapoda: Malacostraca)

Abstract The crustacean fossil record is dominated by mineralized forms. These fossils, in turn, are mainly decapod chelae or parts of chelae. Studies of the composition of modern crustacean cuticles have likewise been dominated by decapods. We summarize major element chemical analyses (Ca, Mg, Na, P) using SEM-EDS of modern crustacean exoskeletons from Bermuda, Georgia (USA), and Lake Tanganyika (Burundi). Although most specimens were brachyuran and anomuran crabs, material also included examples of stomatopods, isopods, caridean shrimps, and achelatans. Transects were made of sections of the carapace, palm of the propodus, and tips of either the dactyl or propodus. Multiple transects were made of the Bermudan land crab Gecarcinus lateralis. Additional studies were made of brachyuran fossil crabs from Texas and South Dakota and of brachyuran crabs having undergone ten months of burial in marine sediments. Overall, the tips of the chela were the thickest and most heavily mineralized regions and had the lowest phosphorus content. In nearly all cases, they also had the lowest ratios of Mg to Ca. One notable exception was Gecarcinus, where the denticles had elevated Mg:Ca values. Anomura and Brachyura had markedly different composition from Stomatopoda and possibly Isopoda, suggestive of independent evolutionary origins of biomineralization within the Crustacea. There were also significant differences in composition between brachyuran crabs from Georgia and Bermuda, perhaps due to differences in water temperature. The fossil crustaceans had much more phosphate in their cuticles, likely as a result of diagenetic processes. Composition should be a first order control on the fossil record of crustaceans. Future studies need to expand the taxonomic and geographic ranges of material examined, determine whether there are environmental controls on composition, and explore the relevant diagenetic processes.

Conserved organ-specific microbial assemblages in different populations of a terrestrial crab.

Microorganisms are ubiquitous in the environment and provide genetic and physiological functions to multicellular organisms. Knowledge on the associated microbiota is becoming highly relevant to understand the host's ecology and biology. Among invertebrates, many examples of endosymbiosis have been described, such as those in corals, ants, and termites. At present, however, little is known on the presence, diversity, and putative roles of the microbiota associated to brachyuran crabs in relation to their environment. In this work we investigated the associated microbiota of three populations of the terrestrial brachyuran crab Chiromantes haematocheir to find evidence of a conserved organ-specific microbiome unrelated to the population of origin and dissimilar from environmental microbial assemblages. Bacterial 16S rRNA gene and fungal ITS sequences were obtained from selected crab organs and environmental matrices to profile microbial communities. Despite the presence of truly marine larval stages and the absence of a gregarious behaviour, favouring microbiota exchanges, we found common, organ-specific microbiota, associated with the gut and the gills of crabs from the different populations (with more than 15% of the genera detected specifically enriched only in one organ). These findings suggest the presence of possible functional roles of the organ-specific microbiota.

Effects of molting on the expression of ecdysteroid biosynthesis genes in the Y-organ of the blackback land crab, Gecarcinus lateralis

A pair of Y-organs (YOs) synthesize ecdysteroids that initiate and coordinate molting processes in decapod crustaceans. The YO converts cholesterol to secreted products through a biosynthetic pathway involving a Rieske oxygenase encoded by Neverland (Nvd) and cytochrome P450 monooxygenases encoded by Halloween genes Spook (Spo; Cyp307a1), Phantom (Phm; Cyp306a1), Disembodied (Dib; Cyp302a1), and Shadow (Sad; Cyp315a1). NAD kinase (NADK) and 5-aminolevulinic acid synthase (ALAS) support ecdysteroid synthesis in insects. A 20-hydroxylase, encoded by Shed in decapods and Shade in insects, converts ecdysone to the active hormone 20-hydroxyecdysone (20E). 20E is inactivated by cytochrome P450 26-hydroxylase (Cyp18a1). Contigs encoding these eight proteins were extracted from a Gecarcinus lateralis YO transcriptome and their expression was quantified by quantitative polymerase chain reaction. mRNA levels of Gl-Spo and Gl-Phm were four orders of magnitude higher in YO than those in nine other tissues, while mRNA levels of Gl-NADK and Gl-ALAS were similar in all ten tissues. In G. lateralis induced to molt by multiple leg autotomy, YO mRNA levels of Gl-Nvd, Gl-Spo, Gl-Phm, Gl-NADK, and Gl-ALAS were highest in intermolt and premolt stages and lower in postmolt. Gl-Dib mRNA level was not affected by molt stage. mRNA level of Gl-Sad, which converts 2-deoxyecdysone to ecdysone, was higher in mid- and late premolt stages, when YO ecdysteroidogenic capacity is greatest. Gl-Cyp18a1 mRNA level was highest in intermolt, decreased in premolt stages, and was lowest in postmolt. In animals induced to molt by eyestalk ablation, YO mRNA levels of all eight genes were not correlated with increased hemolymph 20E titers. These results suggest that YO ecdysteroidogenic genes are differentially regulated at transcriptional and translational levels.

Coastal Forest Structure Survey and Associated Land Crab Population in Suao Dakenggu Community, Yilan, Taiwan

Coastal forests can increase the resilience of seaside communities against natural disasters. These forests also provide other benefits, including food and an avenue for economic growth. The Dakenggu community in Suao, Yilan (Taiwan), is adjacent to a coastal forest with an area of nearly 114,000 m2. Artificial plantation has been performed locally in this area since 1977 to prevent the loss of beaches. The coastal forest area was estimated through drone aerial photography combined with a geographic information system. We found that Pandanus tectorius (11.5%), Casuarina equisetifolia (30.8%), Cerbera manghas (4.07%), Hibiscus tiliaceus (5.2%), and grass (23.52%) are the dominant species in the plant community of Dakenngu coastal forest, which together accounted for 75.1% of the total land area. The area covered by different species in the coastal forest was examined and estimated as well. The height and diameter at breast height (DBH) of the main tree species in five transects were surveyed, and we also found some significant differences among transects that correspond to cohorts planted at different times by the Forestry Bureau. We also performed a survey of land crabs in the same transects over five months to infer any differences in land crab species among the transects. We found that the transect dominated by H. tiliaceus had a larger population of land crabs than others. We revealed that the mudflat crab Chiromantes haematocheir prefers to live under H. tiliaceus. Finally, we propose recommendations for improving the biodiversity of the Dakenggu coastal forest so that it can become a sustainable resource for its residents.

Habitat use, non-breeding groupings and chromatic pattern in Johngarthia lagostoma (H. Milne Edwards, 1837) (Decapoda, Gecarcinidae) in Trindade Island, South Atlantic Ocean

The land crab Johngarthia lagostoma is endemic to Trindade Island, Atol das Rocas, Fernando de Noronha and Ascension Islands. The natural history of the species in non-breeding periods is little known. Therefore, here we reported the formation of non-breeding groups and evaluated the chromatic populational pattern of J. lagostoma in Trindade Island. Records were obtained between April and June 2015. The groups were characterized according to their location, terrain elevation, environmental characteristics and specimens’ behavior. The chromatic pattern was defined by the classification of individuals between yellow and purple, and the proportion of each color was compared between populational units (previously defined based on genetic differences). Non-breeding groups were recorded in four locations in Trindade Island, at altitudes < 40 m, and all of them were in locations with food resources and sediment suitable for the construction of shelters. Isolated individuals or the absence of the species were observed in the most inhospitable places, indicating that the maintenance of the species depends on portions of suitable habitat amid the currently arid matrix. Yellow individuals (96.4%) were predominant on Trindade Island and the chromatic pattern differed from the other populations. Color patterns seem to follow genetic differences between populations, and the founder effect may account for current patterns. From the data obtained, we emphasize that the maintenance of the species may depend on food, sediment suitable for shelters construction, humidity and shade. Due to the significant population decline in other regions, the need to define guidelines for the conservation of the species on Trindade Island is highlighted. In this context, the regeneration of insular vegetation and prohibiting the known anthropic consumption of individuals may represent important strategies for the maintenance of the species.