Host plant utilization by butterfly larvae in the Andaman and Nicobar Islands (Indian Ocean)

The larval food plants of the butterflies of the Andaman and Nicobar islands have not been studied, although the butterfly fauna per se is fairly well known. For the first time we report the food plants of the larvae of 120 species of butterflies from these islands on the basis of laboratory rearing and field studies. This information is essential for the formulation of management programmes for butterfly conservation on these islands which are known to harbour critical swallowtail and (possibly) danaine faunas.     

Increased sea level promotes coral cover on shallow reef flats in the Andaman Sea, eastern Indian Ocean

Sea level in the Indian Ocean is subject to considerable temporal and spatial variabilities. During the period 1960–2009 at Phuket, Thailand, in the NE Indian Ocean, mean sea level increased by 2.7 mm y⁻¹. Regular monitoring of coral cover on fringing reef flats at Phuket since 1979 revealed a sensitive response of this habitat to both transient sea-level depressions and sea-level elevation. Since 1987 when more frequent sampling began, coral cover was positively correlated with the mean sea level experienced over the preceding months. Changing mean sea level explained a high proportion of the observed variation in cover, with overall increasing sea levels and a lack of negative sea-level anomalies promoting cover on the outer reef flats. Concomitantly, there have been no changes in reef community structure or any apparent shifts in zonation patterns across the reef. While future benefits of continued increases in mean sea level on reef flats in the region will be constrained by the frequency and intensity of sea-level depressions associated with the Indian Ocean Dipole, and bleaching events, the overall picture for these shallow reefs is a positive one as they respond to increasing sea level and show rapid recovery from environmental disturbances.     

Fishes of the family Pseudochromidae (Perciformes) in the northwest Indian Ocean and Red Sea

An account is given of pseudochromid fishes from the northwest Indian Ocean and Red Sea. Thirteen species are recorded; four new species of Pseudochromis and two new species of Chlidichthys (all from the Red Sea) are described. Keys are provided, and details are given of the ecology, maintenance in aquaria, and spawning of pseudochromids. As an appendix, a new name is proposed for Pseudochromis punctatus Kotthaus, 1970.     

Fertility tracers and monsoon forcing at an equatorial site of the Somali Basin (Northwest Indian Ocean)

Temporal changes in biological and isotopic tracers have successfully been used to monitor monsoon variability in the Arabian Sea. Convincing evidence that fertility indicators, such as the relative abundance of the planktic foraminifer Globigerina bulloides, and SiO₂ and Ba fluxes, can monitor monsoon changes, has also been published. Time series of the ¹³C content of the thermocline foraminifer Neogloboquadrina dutertrei, and of an Upwelling Radiolarian Index (URI), have been used to reconstruct upwelling changes in the Somali Basin at 5 °N for the last 160 kyr. In order to establish a reference site for comparison with other upwelling and/or fertility records from the same area, a time series of 8 climatic and fertility proxies (¹³C content of N. dutertrei and Globorotalia menardii, percentages of G. bulloides and of a thermocline foraminiferal group, minimal δ¹⁸ values of Globigerinoides sacculifer, N. dutertrei and G. menardii) are investigated in the spectral domain for the last 360 kyr, at a site located at the equator and outside the Somali upwelling centers (Core MD 85668).Chronostratigraphies for these records are developed by correlation of oxygen isotope record of G. sacculifer to the Martinson standard stacked benthic oxygen isotope record. The temporal resolution of the data, is between 2 and 5 kyr.Cross spectral comparisons with ETP (Eccentricity + Tilt + Precession-composite signal) were used to estimate coherences in conjunction with phase relationships and to quantify relationships between fertility and climatic indicators. The timing of fertility indicator cycles at the equator shows little (obliquity band) or no (other orbital bands) coincidence with monsoon proxies of the Arabian Sea. At the equator, fertility responses are dissociated, and present important leads or lags with ETP signal at the three orbital bands (with the exception of the thermocline foraminifera, in phase with maximum eccentricity). Due to significant leads with ETP in the timing of ¹³C minima and URI cycles, no relationships with the Northern Hemisphere radiation can be deduced. At the obliquity and precessional frequency bands, thermocline foraminifera cycles display significant lag with ETP and ice volume minima, which suggests that radiation is not the sole forcing mechanism. Global climatic and ice volume changes may be an important forcing mechanism for these fertility proxies. The G. bulloides record is more complicated with cycles in phase with Arabian Sea monsoon proxies at the obliquity band, and ¹⁸O minima at the precession frequency.It appears that, at the equator, the southwest monsoon winds are not the main force driving radiolarian and foraminiferal productivity.     

The Taxonomy and Phylogeny of Echinometra (Camarodonta: Echinometridae) from the Red Sea and Western Indian Ocean

The number of valid species in the genus Echinometra (Echinodermata, Echinoidea) and their associated identification keys have been debated in the scientific literature for more than 180 years. As the phylogeny and dispersal patterns of these species have been widely used as a prominent model for marine speciation, new insights into their taxonomy have the potential to deepen our understanding of marine speciation processes. In this study we examine Echinometra taxonomy, combining morphology and molecular tools. We present the taxonomy and phylogeny of Red Sea and Western Indian Ocean Echinometra. The currently available morphological keys were found to be limited in their ability to delineate all species within this genus. Nonetheless, morphological similarities between the Red Sea and Western Indian Ocean populations were high, and delimited them from the other species. These latter populations together formed a monophyletic clade, genetically distant from any of the other Echinometra species by more than 3%. Combining both traditional taxonomy and molecular evidence, we found that these populations were neither Echinometra mathaei nor E. oblonga, as previously considered. The morphological discrepancies of these populations, and their genetic divergence from the other Echinometra species, suggest that they should be considered as a new Echinometra species.     

Prionospio atrovitta (Annelida: Spionidae), a new species from Andaman and Nicobar archipelago,northern Indian Ocean

ABSTRACT

A new species of polychaete, Prionospio atrovitta, is described from the sandy sediments of the Andaman and Nicobar insular margin. The major feature distinguishing P. atrovitta from other species of the genus Prionospio is the presence of well-marked black pigmented band near the anterior dorsal margin of the prostomium and pigmentation on the caruncle in the adults.     

New Distributional Record for the Two Gobies (Gobiidae) from the North-Eastern Arabian Sea,Indian Ocean

Journal of Ichthyology - Gobiopsis canalis, checkered goby is one of the rare species of the genus Gobiopsis, with information available from few specimens only. In the present study, this species...     

Vertical distribution of mesozooplankton in the central and eastern Arabian Sea during the winter monsoon

The vertical distribution of mesozooplankton in the centraland eastern Arabian Sea was investigated during the winter monsoonin 1995. Samples were analysed from discrete depth zones definedaccording to oxygen and temperature profiles of the water column.Zooplankton had higher standing stock in the mixed layer comparedto the strata below. The mixed layer had 78.5% of the totalcolumn biomass, while the deepest (500–1000 m) layer accountedfor only 0.9%. The stratum between 500 and 1000 m had the lowestabundance of copepods as well as other zooplankton. A notablefeature was that zooplankton biomass and density did not showmuch variations between coastal and offshore regions. Copepodawere the dominant group. Herbivores were generally more abundantat all depths. A total of 94 species of calanoid copepods wereidentified. Based on vertical distributions, they were assignedto four groups: (i) species restricted to the upper 200 m; (ii)predominantly surface-living species with tails to deeper waters;(iii) sparser deeper-living species generally confined below300 m; (iv) species occurring throughout the water column. Diversitywas fairly high in all strata with equitability being higherin the deeper strata.     

Penilia avirostris DANA in the Indian Ocean (Cladocera)

The records of the marine cladoceran Penilia avirostris DANA in the Indian Ocean are discussed as a further contribution to studies on the features of its world distribution. The review has pointed out different aspects of the life cycle of the species and the influence of biological and environmental factors upon the mechanisms of the cycle itself. Production of P. avirostris is considered on a trophic basis. Observations carried out elsewhere are also discussed.     

Origin and diversification of Indian Ceropegieae (Apocynaceae) and its possible relation to the Indian monsoon

The Indian subcontinent has experienced a major shift in climatic regime from a wet tropical regime to increased seasonal rainfall, since the late Miocene. This shift has been attributed to the intensification of monsoons, which led to opening up of dry habitats in humid forests and formation of deciduous forests. We explored the role of this climatic shift in the origin and diversification of dry‐adapted plant genera Ceropegia and Brachystelma (Ceropegiae, Asclepiadoideae, Apocynaceae). We sampled Ceropegia and Brachystelma from across India and used five markers (two nuclear and three plastid regions) to reconstruct a global phylogeny of this group. Indian members of the tribe Ceropegiae were derived from Africa through at least four independent dispersal events. All dispersal events occurred in late Miocene after establishment of a monsoon climate. One of these early dispersing lineages underwent rapid radiation in peninsular India, giving rise to around 50 species. Thus, both dispersal and diversification events coincided with the intensification of monsoons and concomitant aridification. The role of environment in the evolution of floral characteristics and root type in the Indian radiation is also discussed. This is one of the first reports on a dry‐adapted endemic radiation of plants in India.     

Postlarval development in shallow and deep-sea ophiuroids (Echinodermata: Ophiuroidea) of the NE Atlantic Ocean

The postlarval phase is an essential period in the life history of marine invertebrates; vulnerable to high mortality, it ultimately influences the distribution and abundance of adult populations. In the deep NE Atlantic, a large number of posdarval ophiuroids have been found during certain times of the year, but their identification is difficult. The present work describes the ontogenesis of 12 post-metamorphic shallow-water or deep-sea ophiuroids from samples collected during the Biofar and Rockall Trough Programmes in the NE Atlantic Ocean. Analysis of the posdarval development reveals that species can be identified from a very early post-metamorphic phase using particular morphological characters. The ontogeny of homologous structures reveals similarities within related groups. However, at the same time, these structures give rise to different adult structures in different taxa. Data on the postlarval development of Ophiura qffinis suggest that this species is more closely related to the genus Ophiocten and a change in generic status is proposed.     

Molecular phylogeny of the spiny lobster genus Palinurus (Decapoda: Palinuridae) with hypotheses on speciation in the NE Atlantic/Mediterranean and SW Indian Ocean

Sequence data derived from the mitochondrial DNA 16S rRNA and COI genes were used to determine the phylogenetic relationships among six Palinurus spiny lobster species. Three species (P. charlestoni, P. elephas, and P. mauritanicus) occur in the northeastern Atlantic/Mediterranean, and the others (P. barbarae, P. delagoae and P. gilchristi) inhabit the southwestern Indian Ocean. Parsimony and model based phylogenetics strongly supported the monophyly of the genus. A combined parsimony analysis based on 1001bp and 274 parsimony informative characters recovered the most resolved phylogeny with >70% bootstrap support for associations among species. The Atlantic P. charlestoni consistently clusters nested within the Indian Ocean clade, and the mtDNA sequence divergence between the two most distant species is 8.24%. If the northward collision of Africa with Eurasia in the Miocene caused the final physical separation between the Atlantic and Indian Ocean taxa, then the Palinurus mtDNA (COI and 16S combined) evolved no faster than 0.18% (lower bound) to 0.36% (upper bound) per lineage per million years. The six extant species occur in the pathways of the North Atlantic and South Indian Ocean gyres, and hypotheses on their radiation are developed relative to the strengthening of boundary currents in the Miocene and life history traits congruent with survival in strong ocean currents.     

The pteridophytes of Mauritius (Indian Ocean): ecology and distribution

A survey of the pteridophytes of Mauritius is presented, including a summary of their habitats, ecology, and phytogeographical affinities. Of the 186 infrageneric taxa recorded from the island, 8 are adventive or naturalized, and 27 are presumed rare or extinct. Major ecological groupings are presented and species are listed for both indigenous and secondary plant communities.     

Siphonostomes (Copepoda -- Cyclopoida) from the Indian Ocean

Siphonostomes (Copepoda — Cyclopoida) from the InternationalIndian Ocean Expedition collections were studied. The groupwas represented by Pontoeciella abyssicola of family Pon-toeciellidaeand Ratania flava of family Rataniidae. This study has extendedthe distribution of both the species considerably, and includesthe first record of the male of P. abyssicola from the IndianOcean and of both species from the Bay of Bengal.     

Cryptic species and parallel genetic structuring in Lethrinid fish: Implications for conservation and management in the southwest Indian Ocean

Analysis of genetic variation can provide insights into ecological and evolutionary diversification which, for commercially harvested species, can also be relevant to the implementation of spatial management strategies and sustainability. In comparison with other marine biodiversity hot spots, there has been less genetic research on the fauna of the southwest Indian Ocean (SWIO). This is epitomized by the lack of information for lethrinid fish, which support socioeconomically important fisheries in the region. This study combines comparative phylogeographic and population genetic analyses with ecological niche modeling to investigate historical and contemporary population dynamics of two species of emperor fish (Lethrinus mahsena and Lethrinus harak) across the SWIO. Both species shared similarly shallow phylogeographic patterns and modeled historical (LGM) habitat occupancies. For both species, allele frequency and kinship analyses of microsatellite variation revealed highly significant structure with no clear geographical pattern and nonrandom genetic relatedness among individuals within samples. The genetic patterns for both species indicate recurrent processes within the region that prevent genetic mixing, at least on timescales of interest to fishery managers, and the potential roles of recruitment variability and population isolation are discussed in light of biological and environmental information. This consistency in both historical and recurrent population processes indicates that the use of model species may be valuable in management initiatives with finite resources to predict population structure, at least in cases wherein biogeographic and ecological differences between taxa are minimized. Paradoxically, mtDNA sequencing and microsatellite analysis of samples from the Seychelles revealed a potential cryptic species occurring in sympatry with, and seemingly morphologically identical to, L. mahsena. BLAST results point to the likely misidentification of species and incongruence between voucher specimens, DNA barcodes, and taxonomy within the group, which highlights the utility and necessity of genetic approaches to characterize baseline biodiversity in the region before such model‐based methods are employed.     

Holocene sea level changes and reef development in the southwestern Indian Ocean

 The sedimentological and chronological study of Holocene reef sequences recovered in drill cores through modern reefs of Mauritius, Réunion Island and Mayotte allows the reconstruction of sea level changes and reef growth patterns during the Holocene. The branching-coral facies systematically predominates over coral head facies throughout the Holocene reef sequences, and Acropora is the main frame builder among the branching forms. The reconstructed sea level curves, based both on identification of coral assemblages and on radiometric U/Th ages, are characterized by a rapid rise between 10 and 7.5 ky BP, followed by a clear inflection between 7.5 and 7 ky BP. The stabilization of sea level at its present level occurred between 2000 and 3000 years ago, probably without a higher sea level stand. Rates of vertical reef accretion range between 0.9 and 7 mm. y^-1. In Mauritius, and also probably in Réunion Island, the reef first tracked, then caught-up to sea level to reach an equilibrium position (“catch-up” growth), while the barrier reef margin off Mayotte has been able to keep pace with rising sea level (“keep-up” growth). Accepted: 1 March 1997