Search Results (9)

The Indo-Pacific, a vast biogeographic of Earth, is influenced by both the Indian and East Asian monsoons. Despite its geographical importance, this region has been less studied compared to East Asia and India. Here, we present speleothem records from southern Thailand that cover the last 1500 years, including a hiatus during the Little Ice Age, providing insights into the interactions among climate dynamics, human influences, and ecological responses to climate change. Notably, our records lack the characteristic cold and warm periods observed in other regions, such as the Dark Ages Cold Period and Medieval Warm Period, which may reflect the complexity of the tropical climate system or the region’s unique topography. The analysis reveals a link between ENSO multi-decadal variability and hydroclimate conditions in southern Thailand, as evidenced by speleothem δ¹⁸O. Furthermore, a comparison between speleothem δ¹³C and the Normalized Difference Vegetation Index (NDVI) indicates significant vegetation changes in the last three decades, corresponding with increased atmospheric CO₂ levels and expansion of agricultural land due to human activities during the Current Warm Period. Additionally, our study suggests that an abrupt increase in sea surface temperatures may enhance vegetation growth in the Indo-Pacific by influencing atmospheric circulation and increasing precipitation. Full article

Butterflies are widely used to analyze biogeographical patterns, both at the global and regional scales. Thus far, most of the latter originated from well-surveyed northern regions, while the species-rich tropical areas lag due to a lack of appropriate data. We used checklists of 1379 butterfly species recorded in 36 federal states of the Republic of India (1) to explore the basic macroecological rules, and (2) to relate species richness and the distribution of endemics and geographic elements to geography, climate, land covers and socioeconomic conditions of the states. The area, land covers diversity and latitude did not affect species richness, whereas topographic diversity and the precipitation/temperature ratio (energy availability) were positive predictors. This is due the geographic and climatic idiosyncrasies of the Indian subcontinent, with its highest species richness in the small, densely forested mountainous northeast that receives summer monsoons. The peninsular effect that decreases the richness towards the tip of subcontinent is counterbalanced by the mountainous forested Western Ghats. Afrotropical elements are associated with savannahs, while Palearctic elements are associated with treeless habitats. The bulk of Indian butterfly richness, and the highest conservation priorities, overlap with global biodiversity hotspots, but the mountainous states of the Western Himalayas and the savannah states of peninsular India host distinctive faunas. Full article

Bentinckia is a genus of flowering plants which is an unplaced member of the tribe Areceae (Arecaceae). Two species are recognized in the genus, viz. B. condapanna Berry ex Roxb. from the Western Ghats, India, and B. nicobarica (Kurz) Becc. from the Nicobar Islands. This work constitutes taxonomic revision, cytogenetics, molecular phylogeny, and biogeography of the Indian endemic palm genus Bentinckia. The present study discusses the ecology, morphology, taxonomic history, distribution, conservation status, and uses of Bentinckia. A neotype was designated for the name B. condapanna. Cytogenetical studies revealed a new cytotype of B. condapanna representing 2n = 30 chromosomes. Although many phylogenetic reports of the tribe Areceae are available, the relationship within the tribe is still ambiguous. To resolve this, we carried out Bayesian Inference (BI) and Maximum Likelihood (ML) analysis using an appropriate combination of chloroplast and nuclear DNA regions. The same phylogeny was used to study the evolutionary history of Areceae. Phylogenetic analysis revealed that Bentinckia forms a clade with other unplaced members, Clinostigma and Cyrostachys, and together they show a sister relationship with the subtribe Arecinae. Biogeographic analysis shows Bentinckia might have originated in Eurasia and India. Full article

The diversity of red algae is significantly increasing; in the recent interest of climate changes, taxonomic and biogeographic studies are needed in untouched regions such as ecological important islands. We examined a collection of Gelidium specimens gathered during the 2010 Atimo Vatae expedition based on the morphology and DNA sequencing of mitochondrial cox1 and plastid rbcL. Both morphological and molecular datasets demonstrated the presence of three species in Madagascar; G. leptum G.H.Boo, L.Le Gall and H.S.Yoon, sp. nov., described here, and G. sclerophyllum W.R.Taylor and G. usmanghanii Afaq-Husain and Shameel. Gelidium leptum is distinguished by thin, slender, flattened thalli with irregular branches, compactly arranged thick-walled cells in medulla, sparse rhizoidal filaments at both sides of branches, and elongate sori of tetrasporangia. Gelidium sclerophyllum, previously considered as endemic to the Tropical Eastern Pacific, is first reported in the Indian Ocean and Hawai’i; G. usmanghanii, previously reported to occur in Pakistan and Oman, also presents a first record in the Southern Hemisphere. Phylogenies inferred from cox1 and rbcL sequences suggests that each of the three species likely diverged from different ancestors. The Madagascan Gelidium comprises two geographical elements; Madagascan endemic (G. leptum) and widespread species (G. sclerophyllum and G. usmanghanii). Full article

Ciguatoxins (CTXs) are naturally occurring neurotoxins that can accumulate in fish and cause Ciguatera Poisoning (CP) in seafood consumers. Ciguatoxic fish have been detected in tropical and subtropical regions of the world including the Pacific and Indian Oceans, the Caribbean Sea, and more recently in the northeast Atlantic Ocean. The biogeographic distribution of ciguatoxic fish appears to be expanding; however, the paucity of CTX standards and reference materials limits the ability of public health authorities to monitor for these toxins in seafood supply chains. Recent reports establish that Caribbean Ciguatoxin-1 (C-CTX1) is the principal toxin responsible for CP cases and outbreaks in the northeast Atlantic Ocean and that C-CTX congener profiles in contaminated fish samples match those from the Caribbean Sea. Therefore, in this work, C-CTX reference materials were prepared from fish obtained from the northeast Atlantic Ocean. The collection of fish specimens (e.g., amberjack, grouper, or snapper) was screened for CTX-like toxicity using the in vitro sodium channel mouse neuroblastoma cytotoxicity assay (N2a cell assay). Muscle and liver tissues from toxic specimens were pooled for extraction and purified products were ultimately profiled and quantified by comparison with authentic C-CTX1 using LC-MS/MS. This work presents a detailed protocol for the preparation of purified C-CTX reference materials to enable continued research and monitoring of the ciguatera public health hazard. To carry out this work, C-CTX1 was isolated and purified from fish muscle and liver tissues obtained from the Canary Islands (Spain) and Madeira archipelago (Portugal). Full article

Traditional diets exist in all cultures and geographic regions, and they often represent healthy eating options. Traditional culinary preparations have, however, often undergone profound change, even in the isolated Himalayan region. Therefore, we adapted methods to identify traditional plant foraging activities to better understand their significance in food system sustainability, as well as to promote innovative local gastronomies. Information on wild food and foraging practices was gathered from varied ethnic groups such as Kashmiri, Gujjars, Pahari, Dogra, Bakarwal, Balti, Beda and Brokpa through interviews (n = 716) and group discussions (n = 67) in four bio-geographic regions of the Jammu and Kashmir Himalayas (J&KH). The data were subjected to ordination techniques (Principal Component Analysis) via R software Ver. 4.0.0. We documented 209 food species, of which 73% were plants and 27% animals, used by the inhabitants of four bio-geographic regions of J&KH. The highest number of food plant species was recorded in Indian Kashmir, followed by Jammu, Azad Kashmir and Ladakh (81, 65, 60 and 27 species, respectively), and the maximum number of animal species was reported in Indian Kashmir, followed by Azad Kashmir, Ladakh and Jammu (33, 21, 19 and 17 species, respectively). The Azad Kashmir and Indian Kashmir regions showed greater similarity, whereas the least overlap was observed between Kashmir and Ladakh. The PCA showed considerable variation between different regions, and specific groups of species were more related to one specific region than others. The reported uses of Abies pindrow, Acacia modesta, Bergenia ciliata, Bergenia stracheyi and Juglans regia among plants, and Jynx torquilla, Streptopelia orientalis and Tadorna ferruginea among animals, are novel for the gastronomy of this part of the Himalayan region. We also recorded for the first time from this region seven unique food preparations of wild animals. This study documented extensive traditional knowledge on the usage of wild species, and is the first scientific description of wild food species and their vernacular names in the Western Himalayas, Jammu and Kashmir. Our findings can contribute significantly to combating food insecurity by revitalizing and reconsidering the rich bio-cultural food heritage around which local traditional communities have developed their food systems. Full article

Hydrothermal vents are chemosynthetically driven ecosystems and one of the most extreme environments on Earth. Vent communities exhibit remarkable taxonomic novelty at the species and supra-species levels, and over 80% of vent species are endemic. Here, we used mitochondrial DNA to identify the biogeographic distribution of Munidopsis lauensis and the heme-binding regions of A1-type COX1 from six species (including M. lauensis) to investigate whether genetic variation in the protein structure affects oxygen-binding ability. We verified the identity of Indian Ocean specimens by comparing sequences from the barcoding gene mitochondrial cytochrome oxidase subunit 1 (COI) with known M. lauensis sequences from the NCBI database. The data show that these are the first recorded specimens of M. lauensis in the Indian Ocean; previously, this species had been reported only in the southwest Pacific. Our findings support the hypothesis that vent fauna in the Pacific and Indian Oceans can interact via active ridges. In the case of the mitochondrial DNA-binding site, the arrangement of heme-binding ligands and type A1 motif of M. lauensis was identical to that in other species. Moreover, our findings suggest that the mechanism of oxygen binding is well conserved among species from terrestrial organisms to hydrothermal extremophiles. Overall, dispersal of the same species to geologically separated hydrothermal vents and conserved heme-binding regions in mitochondrial proteins suggest that hydrothermal species might have evolved from shallow sea organisms and became distributed geographically using a dispersion corridor. Full article

A dynamic habitat index (DHI) based on satellite derived biophysical proxy (fraction of absorbed photosynthetically active radiation, FAPAR) was used to evaluate the vegetation greenness pattern across deserts to alpine ecosystems in India that account to different biodiversity. The cumulative (DHI-cum), minimum (DHI-min), and seasonal (DHI-sea) DHI were generated using Moderate Resolution Imaging Spectroradiometer (MODIS)-based FAPAR. The higher DHI-cum and DHI-min represented the biodiversity hotspots of India, whereas the DHI-sea was higher in the semi-arid, the Gangetic plain, and the Deccan peninsula. The arid and the trans-Himalaya are dominated with grassland or barren land exhibit very high DHI-sea. The inter-year correlation demonstrated an increase in vegetation greenness in the semi-arid region, and continuous reduction in greenness in the Northeastern region. The DHI components validated using field-measured plant richness data from four biogeographic regions (semi-arid, eastern Ghats, the Western Ghats, and Northeast) demonstrated good congruence. DHI-cum that represents the annual greenness strongly correlated with the plant richness (R² = 0.90, p-value < 0.001), thereby emerging as a suitable indicator for assessing plant richness in large-scale biogeographic studies. Overall, the FAPAR-based DHI components across Indian biogeographic regions provided understanding of natural variability of the greenness pattern and its congruence with plant diversity. Full article

The sponge Leucetta chagosensis Dendy (1913) has a wide distribution throughout the Indo-Pacific (IP) region, with previous studies focussing primarily on the western Pacific Ocean. To increase our knowledge of the spatial variation of genetic diversity throughout the IP, we constructed a phylogeny for L. chagosensis for the IP to assess the evolutionary patterns for this species. We generated 188 sequences of L. chagosensis and constructed maximum likelihood and Bayesian inference trees, using concatenated mitochondrial cytochrome oxidase subunit 3 gene (cox3) and nuclear ribosomal RNA gene (28S) markers for the first time. The spatial variation of genetic diversity of L. chagosensis was assessed using a phylogeographic approach. Leucetta chagosensis is composed of five cryptic lineages confined to different biogeographic regions with the specimens found in the Indian Ocean differing significantly from those found in the rest of the IP region. Genetic divergence was particularly high for the cox3 marker, with a low nucleotide diversity but high haplotype diversity for most lineages. This study highlights the need for a sustained effort in studying sponge diversity, boosted by the ongoing discovery of hidden biodiversity among this ecologically important taxon. Full article