Candida auris is a multidrug resistant pathogen that presents a serious global threat to human health. As C. auris is a newly emerged pathogen, several questions regarding its ecological niche remain unexplored. While species closely related to C. auris have been detected in different environmental habitats, little is known about the natural habitat(s) of C. auris. Here, we explored the virgin habitats around the very isolated Andaman Islands in the Indian Ocean for evidence of C. auris. We sampled coastal wetlands, including rocky shores, sandy beaches, tidal marshes, and mangrove swamps, around the Andaman group of the Andaman & Nicobar Islands, Union Territory, in India. Forty-eight samples of sediment soil and seawater were collected from eight sampling sites representing the heterogeneity of intertidal habitats across the east and west coast of South Andaman district. C. auris was isolated from two of the eight sampling sites, a salt marsh and a sandy beach. Interestingly, both multidrug-susceptible and multidrug-resistant C. auris isolates were found in the sample. Whole-genome sequencing analysis clustered the C. auris isolates into clade I, showing close similarity to other isolates from South Asia. Isolation of C. auris from the tropical coastal environment suggests its association with the marine ecosystem. The fact that viable C. auris was detected in the marine habitat confirms C. auris survival in harsh wetlands. However, the ecological significance of C. auris in salt marsh wetland and sandy beaches to human infections remains to be explored. IMPORTANCE Candida auris is a recently emerged multidrug-resistant fungal pathogen capable of causing severe infections in hospitalized patients. Despite its recognition as a human pathogen a decade ago, so far the natural ecological niche(s) of C. auris remains enigmatic. A previous hypothesis suggested that C. auris might be native to wetlands, that its emergence as a human pathogen might have been linked to global warming effects on wetlands, and that its enrichment in that ecological niche was favored by the ability of C. auris for thermal tolerance and salinity tolerance. To understand the mystery of environmental niches of C. auris, we explored the coastal wetland habitat around the very isolated Andaman Islands in the Indian Ocean. C. auris was isolated from the virgin habitats of salt marsh area with no human activity and from a sandy beach. C. auris isolation from the marine wetlands suggests that prior to its recognition as a human pathogen, it existed as an environmental fungus.

Vertical distribution and population structure of Metridia pacifica and M. okhotensis were investigated at Site H in the Oyashio region (western subarctic Pacific) to evaluate their life cycle modes. Although recruitment of M. pacifica continued throughout the year in the top 250 m of the water column, 2 pronounced generations were recognized. The first generation was characterized by rapid development during the spring phytoplankton bloom (generation length: 2-3 mo), and the second by slow development (generation length: 9-10 mo) with overwintering at Stage 5 in deeper-layers (up to 1000-2000 m). In contrast, M. okhotensis was consistently found at depth (250-1000 m) throughout the year, except for excursions to the subsurface layer for spawning during the phytoplankton bloom. Developmental sequences of M. okhotensis could not be resolved very clearly, largely because of extremely low abundance of Copepodite Stages 2 and 3 (C2-C3). As a tentative life cycle scenario, the C1 produced during one year was considered to overwinter and develop to C5 through the phytoplankton bloom of the next year. These C5 overwinter and molt to C6 and reproduce during the phytoplankton bloom of the following year. Thus, the generation length of M. okhotensis is estimated as 2 yr. For both species, active spawning and subsequent growth are closely associated with phytoplankton bloom. For overwintering stages of both species, a large deposition of lipid in the body and its gradual decrease toward the onset of phytoplankton bloom of the next year was seen. While no comparable life cycle data is presently available for M. okhotensis, the present results of M. pacifica are compared with the results from other regions, showing a large betweenregion variation in the life cycle patterns of this species. Further, the present results are discussed in the context of broad overwintering mechanisms of pelagic copepods living in high-latitude seas.

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Two new species of the planktonic copepod genus Tortanus, subgenus Atortus, are described from inter-to sub-tidal water of South Andaman Island, India. The new species are assigned to the tropicus group sensu Othman (1987) and distinguished from the other members of the group by the characteristic morphology of the pair of posterior dorsolateral processes on the fifth pedigerous somite in the female and the antennule and leg 5 in the male. An analysis of previous records of the tropicus species group indicates their sporadic occurrence combined with high species richness in Southeast Asia, suggesting future discovery of even more species by sampling with finer geographic and habitat coverage. RÉSUMÉDeux nouvelles espèces du genre de copépode planctonique Tortanus, sous-genre Atortus, sont décrites des eaux inter-à sub-tidales de l'île Andaman du Sud, Inde. Les nouvelles espèces sont assignées au groupe tropicus sensu Othman (1987) et se distinguent des autres membres du groupe par la morphologie caractéristique de la paire de processus dorsolatéraux postérieurs situés sur le cinquième somite pédigère chez la femelle et par l'antennule ainsi que la patte 5 chez le mâle. Une analyse des mentions antérieures des espèces du groupe tropicus indique leur présence sporadique combinée avec une richesse en espèces élevée en Asie du Sud-Est, suggérant la découverte future d'encore plus d'espèces par un échantillonnage utilisant une couverture plus fine au niveau géographique et de l'habitat.

Background: Comparing meiofaunal assemblages in the seagrass zone with bare sediment will provide information on the structuring factors and phytal preferences of meiobenthic invertebrates since differences in density and diversity of meiofauna are to be expected between vegetated and bare zones. Results: A total of 11 groups of meiofauna, with harpacticoids dominating (51 %) and comprising 48 species within 14 families, have been identified. At all localities, the following harpacticoids were found to be relatively abundant, contributing 30.9 % of all harpacticoids: Longipedia weberi, Canuellina nicobaris, Scottolana longipes, and Parastenhelia hornelli. A highly significant correlation (r = 0.987, r 2 = 0.974, F (1,9) = 337.3, P < 0.001) of meiofaunal assemblage was found between seagrass leaf blades and the canopy sediment compared to bare sediment which was found to have a moderate correlation (r = 0.543, r 2 = 0.294, F (1,9) = 3.756, P = 0.085). In addition, the abundance of harpacticoids was significantly higher (ANOVA, F (2,144) = 19.53, P < 0.001) in seagrass sediments and differed markedly from blades and bare sediments, and the composition was unique in the different zones of the present study. Conclusions: Productive seagrass ecosystems are as yet inadequately studied in the Andaman Islands. This study provides a first step to characterize a faunal group from the seagrass community.