Multi-gene phylogeny of the primary freshwater crab genus Ptychophallus Smalley, 1964 (Pseudothelphusidae: Ptychophallinae) from the Neotropical region.

The diversity of primary freshwater crabs of Central America is underestimated and poorly known, specially when considering both Atlantic and Pacific drainages distribution. Among the family Pseudothelphusidae Ortmann, 1893, the genus Ptychophallus Smalley, 1964 was recently revised using morphological data and encompassing 14 valid species, which are distributed exclusively in Costa Rica and Panama. Despite the informative scenario constructed with this previous study, some uncertainties remained such as those related to the populations distributed along different drainages and the lack of complete information regarding the phylogenetic relationships among the species that belong to this genus. Our phylogenetic reconstruction based on multigenes revealed four lineages. Ptychophallus costaricensis, P. colombianus, P. lavallensis, P. montanus, and P. tumimanus are well-established species, while P. paraxanthusi, P. exilipes and P. tristani were recovered as non-monophyletic in some relationships. Ptychophallus tristani and P. paraxanthusi were determined to be close relatives one with other, but with some representatives showing no clear correspondence and positioning in the molecular phylogeny, which raised doubts about the validity as separate species and/or the accuracy of identifications for some GenBank sequences. Ptychophallus tumimanus and P. montanus are morphologically very similar, but they are positioned in distinct clades. The genetic results confirmed a previous proposal that P. barbillaensis is a junior synonym of P. uncinatus, and P. bilobatus is closely related to P. uncinatus. The findings revealed the presence of one peculiar lineage with one species from Costa Rica compound by the resurrected P. campylus and another species from Costa Rica, originally identified as "P. cf. exilipes"; its morphology, however, did not match with any other analyzed species, which requires further analysis. Finally, possible misidentification in some sequences deposited in the GenBank were detected and should be reviewed. The reconstructed molecular phylogeny for the genus that inhabits both Atlantic and Pacific drainages of Central America provides a better understanding of the knowledge on the evolution of freshwater crabs and represents key information that will serve as baseline for further taxonomic studies on the cryptic biodiversity of this group.

Active Dual Line-Laser Scanning for Depth Imaging of Piled Agricultural Commodities for Itemized Processing Lines.

The accurate depth imaging of piled products provides essential perception for the automated selection of individual objects that require itemized food processing, such as fish, crabs, or fruit. Traditional depth imaging techniques, such as Time-of-Flight and stereoscopy, lack the necessary depth resolution for imaging small items, such as food commodities. Although structured light methods such as laser triangulation have high depth resolution, they depend on conveyor motion for depth scanning. This manuscript introduces an active dual line-laser scanning system for depth imaging static piled items, such as a pile of crabs on a table, eliminating the need for conveyor motion to generate high-resolution 3D images. This advancement benefits robotic perception for loading individual items from a pile for itemized food processing. Leveraging a unique geometrical configuration and laser redundancy, the dual-laser strategy overcomes occlusions while reconstructing a large field of view (FOV) from a long working distance. We achieved a depth reconstruction MSE of 0.3 mm and an STD of 0.5 mm on a symmetrical pyramid stage. The proposed system demonstrates that laser scanners can produce depth maps of complex items, such as piled Chesapeake Blue Crab and White Button mushrooms. This technology enables 3D perception for automated processing lines and offers broad applicability for quality inspection, sorting, and handling of piled products.

Morphological diversity in true and false crabs reveals the plesiomorphy of the megalopa phase.

Brachyura and Anomala (or Anomura), also referred to as true and false crabs, form the species-rich and globally abundant group of Meiura, an ingroup of Decapoda. The evolutionary success of both groups is sometimes attributed to the process of carcinization (evolving a crab-like body), but might also be connected to the megalopa, a specific transitional larval phase. We investigate these questions, using outline analysis of the shields (carapaces) of more than 1500 meiuran crabs. We compare the morphological diversity of different developmental phases of major ingroups of true and false crabs. We find that morphological diversity of adults is larger in false crabs than in true crabs, indicating that taxonomic diversity and morphological diversity are not necessarily linked. The increasing morphological disparity of adults of true and false crabs with increasing phylogenetic distance furthermore indicates diverging evolution of the shield morphology of adult representatives of Meiura. Larvae of true crabs also show larger diversity than their adult counterparts, highlighting the importance of larvae for biodiversity studies. The megalopa phase of Meiura appears to be plesiomorphic, as it overlaps between true and false crabs and shows little diversity. Causes may be common evolutionary constraints on a developmental phase specialized for transitioning.

On population structure and breeding biology of burrowing crab Dotilla blanfordi Alcock, 1900.

Background: The present study investigated the population structure and breeding biology of the burrowing brachyuran crab species Dotilla blanfordi Alcock, 1900, which is commonly found on the sandy beach of Bhavnagar, located on the Gulf of Kachchh, Gujarat coast, India. Methods: Monthly sampling was conducted from February 2021 to January 2022 at the time of low tide using three line transects perpendicular to the water line, intercepted by a quadrate (0.25 m2) each at three different levels of the middle intertidal region: 20 m, 70 m, and 120 m. The quadrate area was excavated up to 30 cm and sieved for specimen collection. The collected specimens were categorised into different sexes viz., male, non-ovigerous female, or ovigerous female. For the fecundity study of D. blanfordi, the carapace width (mm) as a measure of size as well as their wet weight (g), size, number, and mass of their eggs were also recorded. Results: The study revealed sexual dimorphism among the population, with females having significantly smaller sizes as compared to males. The overall population was skewed towards females, with a bimodal distribution of males and females. The occurrence of ovigerous females throughout the year suggests that the population breeds incessantly throughout the year, with the highest occurrence in August and September. A positive correlation was observed between the morphology of crabs (carapace width and wet body weight) and the size, number, and mass of eggs.

Population structure and fecundity of the Xanthid crab Leptodius exaratus (H. Milne Edwards, 1834) on the rocky shore of Gujarat state, India.

Background: The population structure and breeding biology of the Xanthid crab, Leptodius exaratus (H. Milne Edwards, 1834), on the rocky intertidal region of Shivrajpur in Saurashtra coast, Gujarat state, were examined. Method: From March 2021 to February 2022, monthly sampling was conducted during low tide using catch per unit effort in the 500 m2 area. The sampled specimens were categorised into male, non-ovigerous female or ovigerous female. In order to estimate fecundity, the morphology of the crab specimens (carapace width and body weight) as well as the size of eggs, number of eggs and weight of egg mass were recorded. Results: A total of 1,215 individuals were sampled of which 558 individuals were males and 657 individuals were females. The size (carapace width) of males ranges from 5.15 to 29.98 mm, while females ranges from 5.26 to 28.63 mm which shows that the average size of male and female individuals did not differ significantly. The overall as well as monthly sex ratio was skewed towards males with a bimodal distribution while unimodal in females. The population breeds year-round, which was indicated by the occurrence of ovigerous females throughout the year. However, the maximum percentage occurrence of ovigerous females was observed from December to April which indicates the peak breeding season. The size of eggs, number of eggs and weight of egg mass were shown to positively correlate with the morphology of ovigerous females (carapace width and wet weight).

A comparative study on the antennae morphology and ultrastructure of three mud crab species of the genus Scylla from Setiu Wetlands, Terengganu, Malaysia.

Crustaceans possess a range of sensory organs crucial in sensory perception, communication, and various ecological functions. Understanding morphological and functional differences in antennae among species could validate taxonomic differentiation and ecological adaptations. The antennae morphology and ultrastructure of mud crab species within the Scylla genus are poorly understood, and their role in ecological adaptation and species differentiation remains unexplored. This study aimed to describe and compare the morphology and ultrastructure of antennae in Scylla olivacea, Scylla tranquebarica, and Scylla paramamosain. Antennae were carefully excised from each crab and subjected to morphological, morphometric, and ultrastructural analysis. The study revealed that the antennae of Scylla species exhibit similar overall morphology, with a series of segments that tapered toward the upper end. All species possess non-branched single setae on the upper end of each segment. The number of antennae segments varied between species, with S. paramamosain having significantly more segments than S. olivacea. Additionally, the length and width of antenna segments differed among the species, with S. tranquebarica having a rougher antenna surface compared to S. olivacea and S. paramamosain. Our findings suggest that Scylla's antennae are distinct between species, especially in the number of segments and setae size. Such difference might be related to ecological adaptation. The role of antennae in sensory perception and social behavioral cues in mud crabs warrants further investigation. This study serves as a foundational reference for future research on the taxonomy, ecological adaptation, and sensory behaviors in the Scylla genus. RESEARCH HIGHLIGHTS: Variations and similarities in morphology and ultrastructure of three Scylla species can be found in the antennae. Scylla paramamosain had significantly higher number of segments than Scylla olivacea in morphology feature. The antennae surface of Scylla tranquebarica was rougher than that of S. olivacea and S. paramamosain. Antennae of three Scylla species possess non-branched single setae.

Predicting diet in brachyuran crabs using external morphology.

Morphological traits have often been used to predict diet and trophic position of species across many animal groups. Variation in gut size of closely related animals is known to be a good predictor of dietary habits. Species that are more herbivorous or that persist on low-quality diets often have larger stomachs than their carnivorous counterparts. This same pattern exists in crabs and in most species, individuals exhibit external markings on the dorsal side of their carapace that appear to align with the position and size of their gut. We hypothesized that these external markings could be used as an accurate estimate of the crab's cardiac stomach size, allowing an approximation of crab dietary strategies without the need to sacrifice and dissect individual animals. We used literature values for mean diet and standardized external gut size markings taken from crab photographs across 50 species to show that percent herbivory in the diet increases non-linearly across species of brachyuran crab with the external estimate of gut size. We also used data from dissections in four species to show that external gut markings were positively correlated with gut sizes, though the strength of this correlation differed across species. We conclude that when rough approximations of diet quality such as percent herbivory will suffice, measuring external carapace markings in crabs presents a quick, free, non-lethal alternative to dissections. Our results also provide important insights into tradeoffs that occur in crab morphology and have implications for crab evolution.

Stoliczia setoiyenica, a new species of freshwater crab from southern Thailand (Crustacea: Decapoda: Brachyura: Potamidae).

A new species of freshwater crab is described from southern Thailand, near the border with Peninsular Malaysia. Species of Stoliczia are characterised by their relatively flat carapace, a third maxilliped exopod that possesses no or a very short flagellum, and a conical male gonopod terminal segment that lacks or only has a very low dorsal fold. Stoliczia setoiyenica, new species, most closely resembles S. perlensis and S. kedahensis from northern Peninsula Malaysia but can be easily distinguished from congeners by differences in carapace and male gonopod morphology. Comparisons to the two known Thai Stoliczia species, S. panhai and S. ekavibhathai, are also provided for completeness.

Morphometric correlations between dietary and reproductive traits of two brachyuran crabs, Hemigrapsus sanguineus and Aratus pisonii.

Many animals have flexible morphological traits that allow them to succeed in differing circumstances with differing diets available to them. For brachyuran crabs, claw height and gut size are diet-specific and largely reflect foraging strategies, while abdomen width reflects relative levels of fecundity. However, the link between claw size and diet has largely been documented only for primarily carnivorous crabs, while the link between diet and fecundity is strong in herbivorous crabs. We sought to determine the nature of the intraspecific relationship between claw size, dietary habits, and fecundity for two primarily herbivorous crab species, Hemigrapsus sanguineus and Aratus pisonii. Specifically, we examined whether claw size and/or abdomen width can be used as reliable measures of individual diet strategy. To test these hypotheses, we collected crabs and measured the dimensions of their claws, abdomens, and guts. By comparing these dimensions for each individual, we found that strongly predictive relationships do not exist between these traits for the primarily herbivorous species in our study. Thus, identifying external morphological features that can be used to assess diets of primarily herbivorous crabs remains elusive.

Localization of chemical synapses and modulatory release sites in the cardiac ganglion of the crab, Cancer borealis.

The crustacean cardiac ganglion (CG) comprises nine neurons that provide rhythmic drive to the heart. The CG is the direct target of multiple modulators. Synapsin-like immunoreactivity was found clustered around the somata of the large cells (LC) and in a neuropil at the anterior branch of the CG trunk of Cancer borealis. This implicates the soma as a key site of synaptic integration, an unusual configuration in invertebrates. Proctolin is an excitatory neuromodulator of the CG, and proctolin-like immunoreactivity exhibited partial overlap with putative chemical synapses near the LCs and at the neuropil. A proctolin-like projection was also found in a pair of excitatory nerves entering the CG. GABA-like immunoreactivity was nearly completely colocalized with chemical synapses near the LCs but absent at the anterior branch neuropil. GABA-like projections were found in a pair of inhibitory nerves entering the CG. C. borealis Allatostatin B1 (CbASTB), red pigment concentrating hormone, and FLRFamide-like immunoreactivity each had a unique pattern of staining and co-localization with putative chemical synapses. These results provide morphological evidence that synaptic input is integrated at LC somata in the CG. Our findings provide a topographical organization for some of the multiple inhibitory and excitatory modulators that alter the rhythmic output of this semi-autonomous motor circuit.

From copula to fertilization: The reproduction of primitive crab Hypoconcha parasitica (Linnaeus, 1763) (Podotremata: Dromiidae).

This study describes the mating behavior of Hypoconcha parasitica under laboratory conditions highlighting the spermathecal morphology and focusing on the seminal fluid storage and release of spermatozoa. The pairs were kept in aquaria where the mating behavior was recorded and described. The spermathecae of the female were analyzed using scanning electron microscopy, X-ray micro-CT, histology, and histochemistry. No pre- or post-copulatory mate guarding was observed in H. parasitica. The sperm transfer occurred with each pair maintaining the protection shield (bivalve shell) on their dorsum. The pair of spermathecae is covered exclusively by the cuticle, following the Podotremata pattern. Many muscle fiber bundles are attached to the cuticular wall facing toward the cephalothorax cavity, especially covering the lateral and slightly dorso-anterior region toward the apodeme of Sternite 7. The spermathecal organization indicates that the process of sperm release during fertilization occurs through muscular action exerted by the female on the wall of the chamber. Thus, the musculature distribution in Hypoconchinae distinguishes them from described for other Podotremata such as Homolidae, which shows the musculature associated with the spermathecae aperture. Like the Homolidae, the first pleopod in H. parasitica seems to take part in the transfer/ movement of spermatozoa and oocytes between the sternum and abdomen, which forms a temporary chamber where fertilization occurs. In conclusion, the spermathecal morphology and associated structures bring new insights to the mechanisms involved in the sperm storage and fertilization of primitive crabs and how the Dromiidae spermatheca perform a new pattern among the poorly studied Podotremata.

A review of the common crab genus Macromedaeus Ward, 1942 (Brachyura, Xanthidae) from China Seas with description of a new species using integrative taxonomy methods.

Macromedaeus is one of the most common xanthid genera in shallow waters of the Indo-West Pacific. In this study, we describe a new species, Macromedaeus hainanensis sp. nov., and report on two newly recorded species, M. quinquedentatus (Krauss, 1843) and M. orientalis (Takeda & Miyake, 1969) from Hainan Island, South China Sea. M. hainanensis is most related to M. distinguendus (De Haan, 1833-1850) and M. orientalis on the carapace shape and granular appearance, but can be distinguished by unique morphological characteristics especially its front, pereopods and male first gonopod. Taxonomic identities of the six Macromedaeus species recorded from China seas are discussed, and a phylogenetic analyzation is performed on Macromedaeus and related taxa based on three mitochondrial and two nuclear markers (12S, 16S, COI, H3, 18S). Integrated taxonomic evidence is used to support the taxonomic status of each species.

Antifatigue Hydration-Induced Polysaccharide Hydrogel Actuators Inspired by Crab Joint Wrinkles.

Joint wrinkles in animals facilitate frequent bending and contribute to the duration of the joint. Inspired by the morphology and function of joint wrinkles, we developed a bionic hydration-induced polymeric actuator with constructed wrinkles at the selected area. Specifically, we adopt electrical writing to create defined single and double cross-linking regions on chitosan (CS) hydrogel. The covalent cross-linking network was constructed by electrical writing-induced covalent cross-linking between CS chains and epichlorohydrin. Subsequent treatment of sodium dodecyl sulfate allows electrostatic cross-linking at the unwritten area with the simultaneous formation of surface wrinkles. The resulting single and double cross-linking hydrogel demonstrates spontaneous deformation behaviors by the influx and efflux of H2O to the electrostatic cross-linking domain under different ion concentrations. Importantly, the wrinkle structure endows the hydrogel with extraordinary antifatigue bending performance. By regulating the surface morphology and spatial cross-linking, we can design novel biomimetic polysaccharide hydrogel actuators with fascinating functions.

Much more than hooked: Setal adaptations for camouflage in Macrocoeloma trispinosum (Latreille, 1825) (Crustacea: Decapoda: Brachyura).

Several majoid crabs are known to adhere exogenous materials to their bodies, a behaviour called decoration. Until now, the adhesion of exogenous materials to the body is most attributed to the well-known hooked setae. Here, we analysed the carapace of Macrocoeloma trispinosum (Latreille, 1825) under light and electron microscopy to study the different mechanisms allowing majoid crabs to decorate themselves. Five setal types are described here, of which four for the first time: velvet type I, velvet type II, depressa and cattail seta. These setae are morphologically and histologically detailed, and new hypotheses about the fixation of exogenous material on the carapace are explored. M. trispinosum has a complex setal apparatus for the adhesion of the decoration, with tegumental ducts along the shaft of most setae. These tegumental ducts are connected to glands formed by large cells arranged radially (rosette or acini) at the base of the setae, in the connective tissue, just below the epithelium. We could observe these glands in different stages of maturation, and no valve-like structure was observed, which may indicate a continuous flow of protein secretion that could serve as an adhesive substance found in the apex of most setae. This is the first record indicating a potential chemical adhesion mechanism aiding the masking process in decorator crabs.

Larval development of the crab Amphithrax hemphilli (Rathbun, 1892) (Decapoda, Brachyura, Mithracidae) described from laboratory-reared material.

The complete larval development of Amphithrax hemphilli was described, illustrated, and compared with that of the previously described larvae of the genus Mithrax sensu lato. Specimens of A. hemphilli were sampled from the northeastern Brazilian coast. The larval development of A. hemphilli consisted of two zoeal stages and one megalopa. Amphithrax hemphilli shows morphological features in all stages of larval development that differ from those observed in other species of Amphithrax, Mithrax, and Maguimithrax. In the first larval stage, A. hemphilli was the only species with two aesthetascs on the antennule and the coxal endite of the maxillule with five setae. In the second larval stage, A. hemphilli was distinguished from the other species of the genus Mithrax sensu lato by the presence of five setae on the basial endite of the maxilla and 26 setae in the scaphognathite of the maxilla. Finally, the megalopa stage of A. hemphilli is characterized by the number of aesthetascs on the three-segmented exopod of the antennule, the setation of both the endopod of the third maxilliped, and pleonites 1-6. Based on the results obtained in the present study, we verified that the more advanced the larval stage, the more distinct characteristics are observed among species of the genus Mithrax sensu lato, facilitating the identification of species through later larval stages.

Juvenile morphology of the ornamental crab Mithraculus forceps A. Milne-Edwards, 1875 (Crustacea, Brachyura).

The morphology of juveniles of Mithraculus forceps A. Milne-Edwards, 1875, raised in the laboratory, is described. The larvae were obtained from ovigerous females collected in the wild, maintained in the rearing system for culture of crabs (400 L). A total of 229 larvae (zoea I), from 7 females were distributed in lots of 20 larvae kept in glass flasks (500 ml), with seawater circulation and temperature and salinity constants, which were checked daily for molts or deaths. After the larvae reached the juvenile stage, exuviae and dead specimens were deposited in a scientific collection. We analyzed the external morphology (N = 10 ind.) of each size class (total = 8). We determined the number of size classes, based on carapace width CW vs. carapace length CL (mm) and its dispersion points, in which we can observe non-hierarchical groupings with no size classes overlapping. We analyzed the relative growth of the juveniles using the technique "Standard Major Axis'' (Type II regression). The relationships CW vs. CL and CW vs. AW showed negative allometry (b < 1; p < 0.05). The relationships CW vs. CPH and CW vs. CPL are isometric (b = 1; p > 0.05). The most remarkable morphological characters of the juveniles (first size class) are the following: spines at the anterior margin of the carapace, inner marginal teeth in the propodus and dactylus of the chelipeds, number of articles in the antennular endopod and the maxillular endopod, absence of setae on the maxillar endopod, and absence of rudimentary pleopods.

Parasitism-Induced Intersexuality in a Sexually Dimorphic Varunid Crab, Ptychognathus ishii (Decapoda: Varunidae).

Although many animals that perform sexual reproduction exhibit sexual dimorphism, individuals with intersex traits between the traits of males and females appear in some species, depending on environmental factors. Ptychognathus ishii, a varunid crab, exhibits distinctive sexual dimorphism in the morphology of its abdomen, chelipeds and setal tufts on the chelipeds. In this study, however, we report for the first time that intersex individuals with intermediate characters between those of males and females were occasionally found in wild populations. Morphological features of intersex individuals are described. Their taxonomic positions are identified based on DNA sequences of part of the mitochondrial cytochrome c oxidase I (COI) gene. It was shown that the intersexuality was induced by entoniscid parasites, because all intersex individuals were parasitized by entoniscid isopods, identified as Entionella sp. The apparent correlation between parasitism and morphological anomalies suggests that the parasitic isopods affect physiological conditions, leading to the feminization of male hosts.

Effect of size on concentrations and cadmium inducibility of metallothionein in the shore crab Carcinus maenas.

Metallothionein (MT) plays an important role in protecting organisms from the adverse effects of Cd, Hg, Zn and Cu. Investigations on mammals show variations in metallothionein concentrations and inducibility with age. This has never been investigated in invertebrates, and we determined the concentrations and inducibility of metallothionein in gills and midgut gland of different size classes of shore crabs from uncontaminated areas. Metallothionein concentrations in gills and midgut gland ranged between 30 and 40 µg g-1 dry weight with no differences among the different size classes. Concentrations of cadmium, copper and zinc in the midgut gland increased with increasing size of the crabs when the concentrations were expressed on a dry weight basis; water content in the midgut gland increased with the size and only the cadmium concentration increased with size when concentrations were expressed on wet weight basis. There was an inverse relationship between metallothionein and both copper and cadmium concentrations. Smaller crabs exposed to 1 mg Cd L-1 accumulated higher concentrations of cadmium in midgut gland and gills than larger ones and metallothionein concentrations in the midgut gland were higher in the smaller crabs. However, the increase in metallothionein concentration per accumulated unit of cadmium showed a linear increase with the size of the crabs. The ratio [Cd]midgut/[Cd]gills decreased with the size of the crabs. The overall conclusion is that baseline metallothionein concentrations do not change with age in shore crabs, but that the inducibility of metallothionein upon cadmium challenge does.

The first zoeal stage of the yellow land crab Johngarthia lagostoma (Milne Edwards, 1837) (Decapoda: Brachyura: Gecarcinidae).

The objective of this paper is to describe and illustrate the first zoeal stage of the largest land crab of the Tropical Atlantic, Johngarthia lagostoma (Milne Edwards, 1837) (Brachyura: Gecarcinidae). A larval description of J. lagostoma was previously not available. Larvae were obtained from ovigerous females on Rocas Atoll and Fernando de Noronha Archipelago, Brazil. Twenty larvae were randomly chosen to be dissected and described in detail, while 40 others (20 larvae from each island) were measured only. The published description of the congener J. planatus (Stimpson, 1860) larvae was used for a comparison of larval morphology. Some morphological differences between the first zoeal stage of these two species were: The absence or presence of a simple shorter seta on antennule, number of the minute terminal spines on the antenna, setation of the coxal endite of the maxilla, exopod unsegmented of the first and second maxilliped, and a single mid-dorsal seta on first pleonite. These results and differences observed between these species can assist in studies on phylogenetic relationships within the Family Gecarcinidae MacLeay, 1838, as well as in the identification of the larvae of J. Lagostoma in plankton samples from the tropical Atlantic.

Pseudolitochira integra (Miers, 1884) (Crustacea: Brachyura: Pilumnidae): redescribed and illustrated from micro-ct scanning the type female.

The taxonomy of the poorly known pilumnid crab, Pseudolitochira integra (Miers, 1884), has been confused because the original description and figures of the type female have inaccuracies, and the specimen has not been examined in detail since the original publication. Consequently, numerous specimens from the Indo-West Pacific have been incorrectly assigned to P. integra, suggesting that this species is widely distributed. The type female was micro-CT scanned in order to provide video and accurate figures of this rare pilumnid. The female possesses a suite of carapace and pereopodal characters that distinctly distinguish it from other pilumnoid taxa. The species is redescribed, refigured and formally designated as the type species of Pseudolitochira Ward, 1942. The identities of the numerous specimens assigned to P. integra are discussed and the distribution of the species is restricted to the western Indian Ocean for the time being.