Abstract A total of 340 specimens of hermit crabs belonging to 34 species, included in four families and 10 genera were collected from the northern coast of Halmahera, in North Maluku, Indonesia. Two species are reported for the first time from Indonesia: Coenobita pseudorugosus Nakasone, 1988, and Trichopagurus macrochela Komai and Osawa, 2005. The color in life for Diogenes spinicarpus Rahayu and Forest, 1995, Diogenes foresti Rahayu and Hortle, 2002, and Clibanarius bistriatus Rahayu and Forest, 1993 is also reported for the first time. A list of hermit crabs found in northern Halmahera, including its habitat and distribution is presented here. 3 1 Halmahera Maluku Indonesia Nakasone 1988 Osawa 2005 Forest 1995 Hortle 2002 199 here 198 200 19 20 2

Abstract Five anomuran and one brachyuran species collected from continental shelf and slope off southern Brazil have their geographic ranges considerably extended southward: Neolithodes agassizii (Smith), Paguristes spectabilis McLaughlin and Provenzano, Pagurus heblingi Nucci and Melo, Phimochirus occlusus (Henderson), Mixtopagurus paradoxus A. Milne-Edwards, and the brachyuran Euchirograpsus antillensis Türkay. Pagurus heblingi was previously known only from its type locality (off Cabo Frio, Rio de Janeiro) and from off Espírito Santo. Paguristes spectabilis was known only from the holotype (off Trinidad, Caribbean Sea) and two additional females from off Rio de Janeiro. One female was found of the brachyuran Robertsella meridionalis Tavares and Gouvêa, a species previously known only from two males. Additionally, the occurrence of the hermit crabs Dardanus venosus (H. Milne Edwards) and Oncopagurus gracilis (Henderson), and the brachyuran Hexapanopeus paulensis Rathbun are confirmed for Santa Catarina. The record of the brachyuran Neopilumnoplax americana (Rathbun) from Santa Catarina (27°S) probably actually refers to Neopilumnoplax lipkeholthuisi Tavares and Melo, a species described from Rio Grande do Sul (33°S) and Mar del Plata (37°S). southward Smith, Smith , (Smith) Provenzano Melo Henderson, Henderson (Henderson) A MilneEdwards, MilneEdwards Edwards, Edwards Milne-Edwards Türkay Frio Janeiro Santo Trinidad Sea Gouvêa males Additionally H. H (H (Rathbun 27°S 27S S 27 (27°S 33°S 33S 33 (33°S 37°S. 37S 37°S . 37 (37°S) (Smith (Henderson 2 3 (37°S

Abstract The status of the obscure Pagurus bouvieri (Faxon, 1895), a replacement name proposed for the preoccupied Eupagurus smithii A. Milne-Edwards and Bouvier, 1893, was evaluated. Based on types and numerous unreported museum materials, P. bouvieri is found to be synonymous with Pagurus politus (Smith, 1882) a commonly encountered but infrequently discussed northwestern Atlantic species. The taxonomy and geographic distribution of P. politus is updated with a complete synonymy, redescription, and illustrations. The taxonomy of the northeastern Pacific species Pagurus smithi (Benedict, 1892) is also updated, including a redescription with illustrations. Faxon, Faxon (Faxon 1895, 1895 , 1895) A MilneEdwards Milne Edwards Bouvier 1893 evaluated materials P Smith, Smith (Smith 1882 synonymy illustrations Benedict, Benedict (Benedict 1892 189 188 18 1

Abstract The Parapaguridae comprises hermit crabs that inhabit deep-water environments. In these environments, shell availability can be limited, mostly consisting of small and fragile-shelled gastropods. Thus, different strategies have evolved to mitigate this limited shell supply. Sympagurus dimorphus (Studer, 1883) lives in association with a zoanthid cnidarian that creates a pseudo-shell that grows with the hermit crab. In contrast, Oncopagurus gracilis (Henderson, 1888) inhabits small, calcified gastropod shells. Therefore, we selected these two species as models to test sexual dimorphism and shape patterns of their chelipeds and cephalothoracic shield, due to their different shelter acquisition methods. We photographed the animals and digitized the images to employ comparative geometric morphometric techniques. We tested the differences in shape between the sexes within each species, and also tested sexual size dimorphism based on centroid size. For O. gracilis, we found shape differences for the chelipeds and cephalothoracic shield, however, we only observed sexual size dimorphism for the chelipeds. For S. dimorphus, an inverse pattern was found, in which females presented more robust chelipeds, and sexual size dimorphism was present in which males were larger. These differences can be reasonably explained by their shelter acquisition methods, in which O. gracilis depends on small shells that limit growth, while S. dimorphus grows with its cnidarian pseudo-shell. The robustness found in the shape patterns may also be related to their behaviors, e.g., in addition to competition for shells, they also fight during mating. However, we emphasize that future studies with other populations of these species are needed for comparative purposes. deepwater deep water environments fragileshelled fragile shelled gastropods Thus supply Studer, Studer (Studer 1883 pseudoshell pseudo crab contrast Henderson, Henderson (Henderson 1888 Therefore shield methods techniques O however S larger growth pseudoshell. shell. behaviors eg e g e.g. mating However purposes 188 e.g 18 1

Abstract After a study of the type specimens, as well as supplementary materials of the eastern Pacific hermit crab Pagurus gladius (Benedict, 1892), this taxon is transferred to the genus Spathapagurus Lemaitre and Felder, 2011, and a full redescription and illustrations are presented. Morphological similarities of Benedict’s taxon with three other eastern Pacific species (Pagurus albus (Benedict, 1892), Pagurus perlatus H. Milne Edwards, 1848, and Pagurus pseudoalbus Ayón-Parente and Wehrtmann, 2019) are summarized. While examining museum specimens during this study, one female specimen representing a new species of Pagurus Fabricius, 1775, was discovered. This new species, named Pagurus marysolae sp. nov., is fully described and illustrated, and is assigned to Group II (“exilis”) of Pagurus.

Abstract A new genus and two new species of fossil hermit crabs (Anomura, Paguroidea) are described from the southern Pyrenean basins (Huesca, NE Spain). Parapetrochirus nov. with P. robustus n. gen., n. sp., as type species, comes from the lower Eocene (Ypresian) Roda Formation. It preserves both chelipeds exhibiting a notable heterochely, a larger left cheliped and a concavity without granulation in the inner upper portions. Eocalcinus gerardbretoni n. sp. comes from the highest levels of the Arguis Formation (Priabonian) in Yeste locality. This species is characterized by a hemispherical outline and a sinuous lower margin of the chela, which differs from the type species of the genus. The cheliped morphology of such species allows inclusion in the families Diogenidae and Calcinidae, respectively. Fossil paguroids are relatively rare in the Eocene of Spain, therefore, the description of these two new taxa increases the known diversity of this group. Parapetrochirus robustus n. gen., n. sp. inhabited siliciclastic substrates within a prodelta environment and E. gerardbretoni n. sp. was collected from the last levels of coral rudstones just below the continental influence of Yeste-Arrés Formation.

Resumen En este trabajo se describe un nuevo género y dos nuevas especies de cangrejos ermitaños fósiles (Anomura, Paguroidea) correspondientes a las cuencas del sur de los Pirineos en la Huesca, noreste de España. Parapetrochirus nov., con P. robustus n. gen., n. sp. como especie tipo procede del Eoceno inferior (Ypresiano) de la Formación Roda. Este fósil preserva ambos quelípedos con una notable heteroquelia, un quelípedo izquierdo más grande y una superficie cóncava sin granulaciones en las porciones superiores internas. Eocalcinus gerardbretoni n. sp., procede de los niveles más altos de la Formación Arguis (Priaboniano) en la localidad de Yeste. Éste se caracteriza por su forma hemisférica y un margen inferior sinuoso de la quela, lo cual difiere de la especie tipo del género. La morfología del quelípedo de estas especies permite su inclusión en las familias Diogenidae y Calcinidae, respectivamente. Los paguroideos fósiles son relativamente raros en el Eoceno de España, por tanto, la descripción de estos dos nuevos taxones fósiles incrementa la diversidad conocida del grupo. Parapetrochirus robustus n. gen., n. sp. habitaba en los sustratos siliciclásticos de ambiente prodelta y E. gerardbretoni n. sp. fue recolectado en los últimos niveles de los rudstones coralinos, justo debajo de la influencia continental de la Formación Yeste-Arrés.

Abstract A new behavior related to shell care was recently reported for the intertidal hermit crab Clibanarius erythropus (Latreille, 1818) in the Gulf of Cádiz (southwestern Europe). It also has been observed in other species of the diogenid genera Clibanarius Dana, 1952, and Calcinus Dana, 1951, however, it has not been described as an active behavior. In the present study, intertidal hermit crabs from different species and localities were sampled to assess if air-exposure is a shell cleaning behavior restricted to some species of intertidal hermit crabs or if it is a more generalized behavior among species inhabiting intertidal habitats. The results revealed that air-exposure is an active behavior in species of Clibanarius and Calcinus, since we observed it also in Clibanarius albidigitus Nobili, 1901, and Calcinus obscurus Stimpson, 1859, from the Pacific coast of Costa Rica, although not in other intertidal species studied by us. We found interspecific differences in tolerance to physical stress of emerged hermit crabs. This air-exposure tolerance can be interpreted as a physiological adaptation to desiccation stress and is also related to the shell type they inhabit. Also, we provide additional features and details of the air-exposure behavior, combining observations of the first description in 2015 with our new field observations.

Abstract The present study was conducted to examine the occurrence and distribution of early juvenile land hermit crabs of the genus Coenobita on a small beach on the Boso Peninsula, Japan as a basis for understanding the important habitats that land hermit crabs use during the sea-to-land transition. The survey sites were supratidal zones at six points with heterogeneous topography, and visual surveys for early juveniles were conducted from middle July to late October in 2015 and 2016. The number of empty gastropod shells in four quadrats along the intertidal zone at each point was also counted in the 2016 survey. The occurrence of early juveniles varied among survey points and was spatially stable for two successive years. The first appearance and abundance of early juveniles varied among survey years. Early juveniles were abundant at points with a gravel bottom throughout the intertidal zone, and empty gastropod shells were also abundant at these points. The abundance of early juveniles was highly correlated with the amount of empty gastropod shells. Thus, our surveys suggested the importance of the sediment types and abundance of empty gastropod shells in the intertidal zones for settlement and landing by land hermit crabs.

ABSTRACT Rocky shores are ecosystems susceptible to anthropic impact, and the absence of information in Brazil about their biota hampers characterization and conservation measures. Thus, this study analyzed the abundance, richness, diversity and dominance of anomuran and brachyuran communities in sheltered and exposed rocky shores in Anchieta and Guarapari on the coast of Espírito Santo State. It was also studied the community variation concerning the types of rocky shores during the rainy and dry seasons. The organisms were collected manually in the mediolittoral zone of the rocky shores from October 2014 to September 2015. Additionally, temperature and salinity of the water were measured and the rainfall recorded from a meteorological station. In this study, 3,156 individuals were collected, comprising 14 species. The hermit crabs Clibanarius antillensis and Calcinus tibicen were the most abundant species. The three-way ANOVA analysis revealed that there was no interaction between ecological indices and the study locations, rocky shores and seasons. The abundance of the decapod community was statistically different between locations. The richness and diversity indices were higher on the sheltered rocky shore because of the presence of rock fragments and heterogeneous sediments, they are providing higher availability of microhabitats in these areas. There was no relationship between the decapod community and environmental factors, possibly because of a small variation of these factors registered between rainy and dry seasons. It is concluded that the anomuran and brachyuran communities are probably more influenced by biological interactions and physiographic features of rocky shores than by environmental factors.

Abstract Two species of bopyrid isopods from the subfamily Athelginae are recorded from new localities in northeastern Brazil. Parathelges foliatus Markham, 1972 was recorded for the first time from Brazil, in the state of Ceará, parasitising the hermit crab Clibanarius symmetricus (Randall, 1840). Pseudostegias atlantica Lemos de Castro, 1965 is recorded from the state of Ceará, parasitising Clibanarius antillensis Stimpson, 1859. Illustrations, species diagnosis and an updated distribution map are given for each species. Brazil Markham 197 Ceará Randall, Randall (Randall 1840. 1840 . 1840) Castro 196 Stimpson 1859 Illustrations 19 184 185 1 18

ABSTRACT Hermit crabs are common and abundant members of the intertidal community and in sublittoral bottoms, where they play a fundamental role in the trophic chain. This study aimed to determine the composition of the hermit crab fauna, to quantify the density in the natural environment, and to register shells use by main species from subtidal boulder fields, in an island off the southeastern Brazilian coast. Monthly samples were taken from March 2010 to February 2011 on boulder fields on Couves Island, Ubatuba, Brazil, during scuba diving daytime sessions. Three hundred and eighty-three crabs were collected by hand, in a quadrat of 20 m2 belonging to five species: Calcinus tibicen, Dardanus venosus, Pagurus brevidactylus, Paguristes tortugae, and Petrochirus diogenes. The highest densities were recorded for P. brevidactylus and P. tortugae. Hermit crabs occupied shells of 15 gastropod species. Cerithium atratum, Gemophos auritulus, and Morula nodulosa comprised more than 80% of the occupation. The heterogeneity of boulder fields of Couves Island, composed almost entirely of small refuges and crevices, favors the exploration of hermit crab species recorded here, which are characterized by small size. These results, combined with the findings of further studies, can contribute to the development of effective monitoring programs for decapod crustacean species.

Abstract: This study analyzed the taxa associated as epibionts with mollusc shells inhabited by the hermit crab Isocheles sawayai, in order to understand how they affect host crabs. A total of 575 individuals were collected, including 156 females, 103 ovigerous females, and 316 males, which occupied shells of 10 species of gastropods. The epibionts recorded in the shells of I. sawayai belonged to Cirripedia, Polychaeta, Bivalvia, Anthozoa, Demosponge, and Bryozoa. A larger percentage of infestation occurred inside the shell, which may be harmful to the hermit crab because it reduces the internal volume. Ovigerous females used shells with a smaller percentage of infestation (40%), which may be related to the need for more space for the position and development of fertilized eggs. However, a higher proportion of anemones was found in shells used by ovigerous females. The advantage of this association for the anemones and crabs is discussed. The results suggest that shells occupied by epibionts can be a favorable factor for hermit crab survival, mainly for ovigerous females.

Resumen: Los taxones asociados como epibiontes con conchas de molusco usadas por el cangrejo ermitaño Isocheles sawayai fueron analizados para comprender como afectan al cangrejo hospedero. Se recolectó un total de 575 individuos, 156 hembras, 103 hembras ovígeras y 316 machos que ocuparon conchas de 10 especies de gasterópodos. Los epibiontes registrados en las conchas de I. sawayai pertenecieron a: Cirripedia, Polychaeta, Bivalvia, Antozoa, Demospongia y Bryozoa. Dentro de la concha, el porcentaje de infestación fue mayor, lo que puede ser perjudicial para el ermitaño, ya que reduce el volumen interno. Las hembras ovígeras utilizaron conchas con menor porcentaje de infestación (40%), lo que puede estar relacionado con la necesidad de más espacio disponible para la ovoposición y el desarrollo de los huevos fertilizados. Sin embargo, hubo una mayor proporción de anémonas en conchas ocupadas por hembras ovígeras. Se discute la ventaja de esta asociación para las anémonas y los cangrejos. Los resultados muestran que las conchas ocupadas por epibiontes pueden ser un factor favorable para la supervivencia del ermitaño, especialmente para hembras ovígeras.

Abstract For the hermit crabs, one of the most important resources is the shell of gastropod they carry along their life. This shell gives them different benefits like protection, refuge and prevents desiccation. The semi-terrestrial hermit crabs (Family Coenobitidae) perform a behavioral remodeling process from the inside of the gastropod shell, increasing its internal volume and making them lighter. In this study the advantages provided by remodeling a shell were evaluated with a locomotion approach. For this, terrestrial hermit crabs from Coenobita compressus species were collected in Playa Troncones, Guerrero. Locomotion experiments were performed where the crabs walked on wet sand occupying remodeled and non-remodeled shells with the purpose of measure their performance. Depth measurements and type of imprint were taken; also the walking velocity of each crab was measured. As a result we obtained that the hermit crabs occupying remodeled shells had a lower drag, shallower shell traces and they reached a greater speed. Therefore, the benefits of using a remodeled shell were demonstrated from a locomotive point of view. Besides, this study showed an application of the neo-ichnology as an implement in ecological and biological studies.

Resumen Para los cangrejos ermitaño, uno de los recursos más importantes es la concha de gasterópodos que portan a lo largo de su vida. Esta concha les proporciona diferentes beneficios como protección, refugio y evita la desecación. En los ermitaños semi-terrestres (Familia Coenobitidae) se presenta una conducta a través de la cual remodelan sus conchas desde el interior, incrementando el volumen interno y haciéndolas más ligeras. En este estudio se evaluaron algunas ventajas en términos de locomoción que estos organismos adquieren como resultado de este proceso de remodelación. Para esto se recolectaron cangrejos ermitaño terrestres de la especie Coenobita compressus en Playa Troncones, Guerrero. Se realizaron experimentos de locomoción en los que los cangrejos caminaron en arena húmeda ocupando conchas nuevas sin remodelar (pesadas), y conchas remodeladas (ligeras) con el fin de medir su desempeño. Se tomaron medidas de profundidad y tipo de huellas, además de la velocidad de la caminata de cada cangrejo. El resultado fue que los cangrejos que utilizaban conchas remodeladas presentaban un menor arrastre, huellas de la concha menos profundas y alcanzaron una mayor velocidad. Por lo tanto, se lograron demostrar ventajas obtenidas tras remodelar la concha desde un punto de vista locomotriz. Este estudio además nos muestra una aplicación de neo-icnología como herramienta en estudios del área ecológica y biológica.

Abstract Predatory behavior of the crab Eriphia verrucosa (Forskål, 1775) on the oyster Magallana angulata (Lamarck, 1819), the mussel Mytilus galloprovincialis Lamarck, 1819, the limpet Patella depressa Pennant, 1777, the hermit crab Clibanarius erythropus (Latreille, 1818), the gastropod Phorcus lineatus (da Costa, 1778) and the sea urchin Paracentrotus lividus (Lamarck, 1816) was experimentally studied. Taken into account that the sampled population of E. verrucosa was infected with the parasitic barnacle Sacculina eriphiae Smith, 1906, four predator categories were established regarding crab sex and parasite presence: uninfected and infected males and females, respectively. These four crab categories were fed on the six preys offered, but prey remains suggest that the crab obtains the flesh of each prey using different methods of attack. Irrespective of the prey species, uninfected females consistently presented lower percentages of crab feeding and total consumption. On average, it was found that a significantly higher percentage of crabs feed on M. galloprovincialis, P. depressa and Ph. lineatus than on the other three prey species (chi-squared test, p < 0.05). In terms of mean eaten biomass, the preys most eaten were P. lividus and P. depressa and the least eaten was C. erythropus (ANOVA test, p < 0.05). For crabs feeding on M. galloprovincialis and Ph. lineatus there was a significant positive correlation (p < 0.05) between the predator size and prey size, as well as between the predator size and total prey consumption. According to these results, potential effects of this top predator on intertidal communities are also discussed.

Biodiversity and spatial-temporal distribution of hermit crabs captured as bycatch in the non-selective fishery of shrimp were analyzed in this study from July 2010 through June 2011 off coast Santa Catarina State (southern Brazil). Ecological indexes and redundancy analyses were conducted to understand the hermit community and their relationship with environmental factors. In total, 644 specimens were collected, representing two families, five genera, and six species, demonstrating remarkable species richness in the study area, mainly because Santa Catarina is a subtropical region. Isocheles sawayai showed the highest abundance, followed by Loxopagurus loxochelis. Both species demonstrated correlation with temperature (positive) and sediment grain size (negative). The highest richness and evenness values were estimated at the deeper area (17 m). However, in 5 m deep area showed the lowest evenness because of the high dominance of I. sawayai, resulting in a lower estimated diversity. During a period of lower temperature and higher salinity (July), higher levels of diversity were registered, probably because of the lower dominance of tropical species (I. sawayai) and the presence of some species distributed in offshore regions (Petrochirus diogenes, Dardanus insignis and Pagurus exilis). Thus, we detected that the capture effort designated in the shrimp fishery activities had a strong influence in the diversity of hermit crabs and other associated fauna, especially because of catch specimens in expressive abundance at various stages of development, including juveniles. This profile makes us argue in favor of constant monitoring of bycatch resources in order to preserve the marine fauna.

Se analizó la biodiversidad y distribución espacio-temporal de los cangrejos ermitaños, como descartes en la pesca no selectiva de camarón, entre julio de 2010 y junio de 2011 en la costa del Estado de Santa Catarina. Los índices ecológicos y análisis de redundancia se analizaron para describir el desarrollo de la comunidad de ermitaños y su relación con los factores ambientales. Se encontró una notable riqueza específica en una región subtropical, como fue la de Santa Catarina, donde se obtuvieron 644 individuos pertenecientes a dos familias, cinco géneros y seis especies. Isocheles sawayai presentó la mayor abundancia, seguida de Loxopagurus loxochelis; ambas especies mostraron correlación con la temperatura y tamaño de las partículas del sedimento. Los mayores valores de riqueza y uniformidad se dieron en la zona más profunda estudiada (17 m). Sin embargo, a 5 m de profundidad se encontró la equirepartición más baja debido al predominio de I. sawayai. Durante un período de baja temperatura y mayor salinidad (julio) se registraron altos valores de diversidad, probablemente debido la baja dominancia de especies costeras tropicales (I. sawayai) y presencia de algunas especies de aguas oceánicas (Petrochirus diogenes, Dardanos insignis y Pagurus exilis). Se detectó que el esfuerzo de captura aplicado en las pesca del camarón tuvo una fuerte influencia en la diversidad de los cangrejos ermitaños y fauna asociada, especialmente debido a que en las muestras se observaron diversas etapas de desarrollo de las especies, incluyendo juveniles. Estos resultados son argumentos a favor de una vigilancia constante de los descartes a fin de preservar la fauna marina.