Southwestern India Research Articles

A new earthworm genus with two new species (Clitellata, Megascolecidae) from the Western Ghats mountain ranges of south-western peninsular India

A new megascolecid earthworm genus, Aiyeriella Narayanan & Julka gen. nov., is established from the Western Ghats biodiversity hotspot of India, with two new species, namely, A. quadritheca Narayanan & Julka, sp. nov., and A. longiprostata Narayanan & Julka, sp. nov. Material of the new genus and species were collected from the three southernmost districts of Kerala state, in the south-western portion of peninsular India. The present new genus can be distinguished from other related Indomalayan megascolecid genera by the presence of combined male and prostatic pores paired in seminal grooves on segment 18, with a single well-developed oesophageal gizzard in segment 5, penial setae, calciferous glands, intestinal caeca, and typhlosole absent, meronephric throughout the body, 10–14 in transverse bands of micromeronephridia behind clitellum and prostates tubuloracemose, paired, elongated, and strap-shaped.

Impact of land use/land cover and climate change on streamflow variations in heterogeneous river basins of south-western India

ABSTRACT This study examines the spatial and temporal variations in streamflow due to Landuse/Land cover (LULC) and climate change within four heterogeneous river basins along south-western India: Kuttiyadi and Korapuzha–Kallai (North), Chalakudy (Centre), Karamana–Neyyar (South) River basins. A Soil Water Assessment Tool (SWAT) was used to assess the impact of projected LULC and climate scenarios. Five General Circulation Models (GCMs), CanESM2, BNU-ESM, CNRM-CM5, MPI-ESM-LR and MPI-ESM-MR under two Representative Concentration Pathways (RCP) RCP 4.5 and RCP 8.5 were employed. The combined scenarios include Near future (NF) – 2011-2030-LULC 2030, Mid-future (MF) – 2031-2070-LULC 2070 and Far future (FF) – 2071-2100-LULC 2100. The projected streamflow was then analysed to identify significant trends using the Mann–Kendall Trend test. Under RCP 4.5 and RCP 8.5, average annual streamflow is expected to increase in the NF (8.5% to 20.6% from south to north). However, in the FF, streamflow is expected to decrease (−2.4% to +2.2% from south to north), under RCP 4.5. Trend analysis shows that climate change is unlikely to cause significant trends in the NF, except in the central river basin. However, significant trends are expected in the FF. Water resources planners may consider these future trends while preparing water resources management plans.

On three new species of the earthworm genus Drawida Michaelsen, 1900 (Clitellata: Moniligastridae) from south-western India.

Three new earthworm species of the genus Drawida Michaelsen, 1900, namely D. jatinderi Narayanan, sp. nov., D. paliwali Narayanan, sp. nov. and D. proboscidea Narayanan, sp. nov., are described from materials collected from the Kerala state of south-western India. D. jatinderi Narayanan, sp. nov., belongs to D. travancorensis Michaelsen, 1910 species group, characterized by spermathecal pores at C setal line, male pores at mid bc setal lines, glandular prostate, spermathecal atrium present, dorsal pores, and genital markings absent. Whereas D. paliwali Narayanan, sp. nov., and D. proboscidea Narayanan, sp. nov. belong to the D. robusta robusta (Bourne, 1886) group, characterized by glandular prostates and bilobed spermathecal atria. D. jatinderi Narayanan, sp. nov., and D. proboscidea Narayanan, sp. nov. were collected from the midlands of Ernakulam district, and D. paliwali Narayanan, sp. nov., was collected from the higher altitude evergreen forest of the Parambikulam Tiger Reserve of Palakkad district. Here we provide a detailed description of the external and internal characteristics of the new species, along with illustrations of the key characters. With the new findings, a total of 52 Drawida species are known from the Western Ghats biodiversity hotspot.

A qualitative study to explore traffic police personnel perceptions towards road safety behaviour among young riders in Manipal, India

Road crash injuries are significant public health issues in many low-and middle-income countries. Every year more than 1.35 million people lose their lives due to road crashes, making it one of the leading causes of death worldwide. In 2021, 1.19 million road traffic deaths occurred worldwide. Globally, India accounts for the second-largest number of fatal road traffic crashes. Riders in the age range of 18–25 years contribute to 41.4% of India’s total road crash victims. An in-depth understanding of the current traffic density, violations, and behaviours of young riders is essential for enforcement agencies, in particular, the traffic police personnel. Their perspective is relevant as they have a unique position to judge and evaluate the riding behaviours and the efficiency of the existing intervention programmes. Furthermore, their suggestions can be highly effective in developing evidence-based risk reduction programmes. The present study was conducted in Manipal, which is a locality of Udupi district in Karnataka province of Southwestern India. Seventeen in-depth interviews were conducted from October 2018 to January 2019 among traffic police personnel. Thematic analysis was done using ATLAS.ti 8 software to identify, analyse, and report themes within the data. Respondents revealed that in recent times Manipal roads have become unsafe for young riders. Factors such as speeding, using a mobile phone while riding, reckless riding, and overtaking from the wrong side were the main reasons for road traffic crashes. Interventions like the installation of traffic barricades, closed-circuit television cameras, speed breakers, and signboards at the crash hotspots, together with strict enforcement of traffic laws, were suggested by the respondents to reduce crashes. The study findings highlight the importance of traffic police personnel’s views in understanding the various determinants for road crashes observed among young riders. Future research can be taken up in other settings with broader age group involvement for the target population. There is a need to establish a coordination committee that can locally organize awareness programmes involving all the stakeholders on road safety to increase the level of risk perception and reduce crashes.

Sedimentary records of liquefaction from central Kerala (southwestern India), as earthquake indicators in a cratonic area

Far from the plate boundaries, the seismogenic zones within the cratonic areas of Indian land mass had remained largely undetected. The moderate earthquakes in such areas have proved to be hugely damaging because of their infrequency and consequent lack of societal preparedness. As the subtle geological expressions of tectonism make identifying hazardous zones in cratonic areas difficult, it is important to develop locally appropriate geological criteria to isolate potential seismic source zones. Although seismically induced liquefaction preserved in the sedimentary sections is useful as an earthquake proxy, its scope remains underestimated in cratonic regions. Here we offer a field-based methodological approach to mapping liquefaction features from such an area, located south of the Bharathapuzha River in the southwestern part of the Indian craton. We used the field data to constrain the near-field earthquake potential. The earthquake-induced soil liquefaction, in the form of sand dikes and sills, was identified within an area of roughly 100 km2, and the available data suggest two episodes of liquefaction – the one between 2.0 ka and 2.5 ka, and a later event around 0.78 ka BP. The spatial distribution and the dimension of the soil liquefaction features, in an area known for the occasional spurt in minor earthquakes in recent times, are suggestive of a potential seismic source in the region that can generate earthquakes of moment magnitudes (Mw) ranging from 5.5 to 6.5.Thus the present observation is a vital input for constraining the region’s seismic hazard and the methodology developed here can be used in other areas of unknown potential.

Taxonomic revision of the king cobra Ophiophagus hannah (Cantor, 1836) species complex (Reptilia: Serpentes: Elapidae), with the description of two new species

The taxonomy of king cobras (Ophiophagus) was reevaluated using qualitative, mensural and meristic characters, based on 148 entire and five skeletal specimens, and supported by a recent molecular phylogenetic analysis. We provide nomenclatural synopses of both the genus and species-series nomina. We restrict the concept of Ophiophagus hannah s. str. to populations from eastern Pakistan, northern and eastern India, the Andaman Islands, Indo-Burma and Indo-China, south to central Thailand. The nomen Ophiophagus bungarus (Schlegel, 1837) comb. nov. is revived for the populations inhabiting the Sunda Shelf area, including the Malay Peninsula, the Greater Sunda Islands and parts of the southern Philippines. We describe two new species, Ophiophagus kaalinga Gowri Shankar, Das & Ganesh sp. nov. endemic to the Western Ghats of south-western India and Ophiophagus salvatana Gowri Shankar, Das & Wüster sp. nov., inhabiting the island of Luzon in northern Philippines. For the purpose of nomenclatural stability, we designate a neotype for Hamadryas hannah Cantor, 1836. A dichotomous identification key to the four species recognized here is provided.

Reconstructing the past environmental conditions of southwestern India using estuarine sediment core

Geological archives can be examined via multiple proxies to uncover significant information about historical environmental changes. In comparison to single proxy approach, the use of multiple proxies can provide better resolution of the paleoenvironmental record. Thus, in the present study, to understand the paleoenvironmental conditions in the Kali coast in southwestern India, sedimentological, geochemical and isotopic (210Pb, 137Cs) proxies were used. The findings demonstrated that, in previous decades, the sedimentation rate varied from 0.5 to 1.0 cm/year under conditions with relatively higher hydrodynamic energy that were more common and fluctuating, allowing for larger sand particle deposition. However, in more recent years, finer particle deposition towards the surface has been observed under conditions with lower and more stable hydrodynamic energy, with a sedimentation rate of 1.87 cm/year. Additionally, the finer fractions displayed a strong correlation with the metal distribution, which was mostly governed by Fe-Mn oxides. Furthermore, it can be revealed that the environment was warm, humid, and marine-like between 1995 and 2000 based on chemical weathering intensity values and Rb/K ratios. A subtle shift to a freshwater habitat with relatively less warm, less humid climate occurred between 2000 and 2020. Therefore, similar research with longer depositional histories coupled with multiple proxies can help predict the future climatic shifts in decadal time scales.

The Role of Women in the Development Path of Kerala

Kerala, a state in southwestern India, has achieved remarkable social and economic development, surpassing many other Indian states. A significant contributor to this success is the empowered role of women in Kerala’s society. This paper examines the crucial contributions of women to Kerala’s development path, highlighting their impact on education, healthcare, economy, and social reform. With a high literacy rate and active participation in the workforce, women have driven positive change and played a vital role in shaping the state’s development trajectory. The paper explores the historical and cultural context that has enabled women’s empowerment in Kerala, discussing the influence of matrilineal traditions, education initiatives, and social movements. By analyzing the experiences and achievements of women in Kerala, this research demonstrates the transformative power of gender equality and women’s empowerment in achieving sustainable development and social progress.

Temporal soil loss scenarios and erosional dynamics of a slopping landmass in the southwestern India before and after the 2018 severe rainfall and mega flood events

Temporal soil loss scenarios and erosional dynamics of a slopping landmass in the southwestern India before and after the 2018 severe rainfall and mega flood events

‘Data Deficient’ but potentially threatened: first biological observations on the poorly known quagga catshark (Halaelurus quagga)

Context The quagga catshark (Halaelurus quagga) is a small-sized (~370-mm total length), deep-water catshark (Family: Pentanchidae), assessed as Data Deficient on the IUCN Red List. Aim We aimed to bridge critical knowledge gaps on aspects of the life history and exploitation of H. quagga to make a meaningful Red List assessment, and develop management plans. Methods Specimens landed as bycatch in three harbours along the Laccadive Sea coast of south-western India were examined to gather the first information on exploited length classes and aspects of reproductive biology. Key results Halaelurus quagga had a female-dominated sex ratio, a positively allometric growth in females, and isometric growth in males. Mature H. quagga males ranged between 294 and 336 mm, and females between 315 and 370 mm, with pregnant females carrying two, three or four egg cases with embryos in each uterus. Conclusions This study provides the first information on the biology and exploitation of H. quagga, showing that the species is landed (and discarded) as bycatch in trawl fisheries, with the catches comprising a significant amount of reproductively active individuals. Implications The intense deep-sea bottom-trawling off south-western India is a major threat to H. quagga, and, if left unmanaged, could likely trigger a threatened category on the IUCN Red List.

Identification of earthworms (Clitellata, Oligochaeta) from Kottayam district in Southwestern India: an integrated traditional and barcoding approach

Earthworms from various land uses in the Kottayam district of Kerala, part of the Western Ghats hotspot in India, were studied using an integrative approach that involved morphoanatomical methods and cytochrome c oxidase I (COI) barcoding techniques for the first time here. The study unveiled the presence of nine earthworm species: <i>Drawida ghatensis</i> Michaelsen, 1910; <i>Moniligaster julkai</i> Narayanan and Paliwal, 2022; <i>Glyphidrilus annandalei</i> Michaelsen, 1910; <i>Pontoscolex corethrurus</i> (Müller, 1857); <i>Eukerria kuekenthali</i> (Michaelsen, 1908); <i>Dichogaster bolaui</i> (Michaelsen, 1891); <i>Megascolex cochinensis</i> Stephenson, 1915; <i>M. konkanensis</i> Fedarb, 1898; and <i>Lampito mauritii</i> Kinberg, 1867, belonging to eight genera. The COI sequences of all nine species were deposited in GenBank. Notably, <i>M. julkai</i> and <i>E. kuekenthali</i> are novel additions to the GenBank barcode database. The Bayesian phylogram and maximum-likelihood indicated that the species <i>M. julkai</i> in this study exhibited a closer relationship to <i>D. ghatensis</i> than to other <i>Moniligaster</i> species. This study provides detailed descriptions and illustrations of all nine species, supplemented by their DNA barcodes, to facilitate future species identification.

Insights into ovarian maturation and reproductive traits of the deep-water penaeid shrimp Metapenaeopsis andamanensis (Wood-Mason in Wood-Mason and Alcock, 1891) from southwestern India

The present study delves into the reproductive characteristics of Metapenaeopsis andamanensis, a commercially significant deep-water shrimp collected from Sakthikulangara, off Kollam, India (8°56′60.78″ N/76°32′34.27″ E) during September 2019 to May 2022. Despite its economic importance, the reproductive traits of this species remain elusive. This research comprehensively examines macroscopic and microscopic features associated with gonadal maturity stages, including determination of size at first maturity (CL50), gonadosomatic index, and fecundity of M. andamanensis. Male-to-female sex ratio was noted as 1:1.03 using chi-square analysis. The smallest mature individuals were observed at 12 mm and 16 mm carapace length for males and females, respectively. Macroscopic observation categorized females into five groups based on gonadal coloration, while microscopic examination identified seven stages using histological characteristics. Notably, the absence of cortical crypts in the periphery of oocyte cytoplasm, a characteristic feature of the genus Metapenaeopsis, was observed in this species. Males were classified into two categories based on macroscopic and microscopic observation. The gonadosomatic index ranged from 4.25 to 10.13 for mature female individuals, exhibiting a significant increase until stage IV. Continuous spawning was observed, with a peak in May and November. The size at first maturity for females and males was determined as carapace length (CL) 23.05 mm and 17.53 mm, respectively. The average absolute fecundity was calculated as 53,889 with an average relative fecundity of 9934 oocytes. This investigation contributes valuable insights into the reproductive traits of the deep-water penaeid shrimp M. andamanensis, facilitating the development of effective management strategies for sustainable fisheries.

Using proxy data and vegetation modelling to predict past, current and future distributional shifts of Butea monosperma, a marker of land degradation in India

Extensive deviations in spatio-temporal social and environmental dynamics currently alter the health of ecosystems and the services they provide. Detecting the causes that contribute to the distribution of a natural forest species capable of restoring the lost ecosystem function and productivity will aid in determining better food security, livelihoods and provision of ecosystem goods and services. We modelled the spatial range of Butea monosperma (B. monosperma) under past, that is, Last Glacial Maximum (LGM), Middle Holocene (MH), current and future (2070) climatic scenarios with Maximum Entropy (MaxEnt) trained on present-day occurrences. We identified areas of suitable habitats for which the estimation of habitat stability is predicted in all the models at different times. To validate the inferred suitable habitat, we tested the model by the current occurrence and fossil pollen data of B. monosperma. Our distribution models agree with the fossil pollen records for the MH (4,500–7,000 yr BP) and predict the prevalence of B. monosperma covering 84.22% of the Indian subcontinent with maximum habitat stability in western and southwestern India (10.95%). The widespread potential distribution of the plant species during the LGM supports the presence of the last remnants of tropical dry deciduous forest in the region. However, a decline in habitat suitability (62.84%) is predicted under current and future climatic scenarios with maximum stability (0.90%–3.09%) along the Western Ghats, Nilgiri hills, Gir range in the western India and north-eastern region covering the Assam Valley and foothills of Tripura and Mizo hills. Temperature seasonality (33.6%) measured in terms of variable contribution in MaxEnt model significantly affects the distribution shift of B. monosperma, along with annual precipitation (22.8%) and annual mean temperature (16.2%). Model results provide evidence of habitat reduction and identify the stability hotspots for B. monosperma for its conservation and establishment of land management policies mainly for the dry tropics.

Validation of localised coastal wind forecasts for artisan fishers of southwestern India

Validation of localised coastal wind forecasts for artisan fishers of southwestern India

Accumulation of microplastics in bivalves within the Chandragiri River in South-Western India

The pervasive presence of microplastics within river ecosystems has a profound and often underestimated detrimental impact. These minuscule yet persistent particles have infiltrated diverse biological habitats, making their detrimental effects on aquatic life increasingly concerning worldwide. The ability of microplastics to accumulate within aquatic organisms further exacerbates this concern. Consequently, the monitoring of microplastic pollution in surface water environments has emerged as a crucial endeavour, offering invaluable insights into the extent of this ecological threat. This study delved into the contamination levels of microplastics within two bivalve species, Perna viridis and Villorita cyprinoides, along the Chandragiri River in Kerala and Karnataka, South-West India, spanning eight distinct locations. The investigation yielded a significant discovery, with a total of 667 microplastic particles extracted from 288 individuals. On average, each individual bivalve harboured approximately 2.31 ± 0.93 microplastic items. Notably, these microplastic particles exhibited a wide range of morphological characteristics, underscoring their diverse origins and pathways into the ecosystem. Furthermore, five polymer types of microplastics were unequivocally confirmed through FTIR-ATR analysis, shedding light on the types of plastics that pose a threat to the riverine ecosystem. The findings of this study contribute to a growing body of evidence highlighting the global threat of microplastic pollution, urging international collaboration and innovative solutions to prevent further contamination and remediate existing microplastic burdens in aquatic environments.

Triple dip La-Nina, unorthodox circulation and unusual spin in air quality of India

The recent La-Nina phase of the El Nino Southern Oscillation (ENSO) phenomenon unusually lasted for third consecutive year, has disturbed global weather and linked to Indian monsoon. However, our understanding on the linkages of such changes to regional air quality is poor. We hereby provide a mechanism that beyond just influencing the meteorology, the interactions between the ocean and the atmosphere during the retreating phase of the La-Niña produced secondary results that significantly influenced the normal distribution of air quality over India through disturbed large-scale wind patterns. The winter of 2022–23 that coincided with retreating phase of the unprecedented triple dip La-Niña, was marred by a mysterious trend in air quality in different climatological regions of India, not observed in recent decades. The unusually worst air quality over South-Western India, whereas relatively cleaner air over the highly polluted North India, where levels of most toxic pollutant (PM2.5) deviating up to about ±30 % from earlier years. The dominance of higher northerly wind in the transport level forces influx and relatively slower winds near the surface, trapping pollutants in peninsular India, thereby notably increasing PM2.5 concentration. In contrast, too feeble western disturbances, and unique wind patterns with the absence of rain and clouds and faster ventilation led to a significant improvement in air quality in the North. The observed findings are validated by the chemical-transport model when forced with the climatology of the previous year. The novelty of present research is that it provides an association of air quality with climate change. We demonstrate that the modulated large-scale wind patterns linked to climatic changes may have far-reaching consequences even at a local scale leading to unusual changes in the distribution of air pollutants, suggesting ever-stringent emission control actions.

Influence of thick lithomargic soil cover on Bouguer gravity low: Imprints from passive continental margin of southwestern India

The Periyar Plateau in central Kerala is characterized by a strong negative Bouguer gravity field around three major islands of a strongly negative field of the value of -150 mGal. Detailed gravity studies reveal that these islands of strong negative field are of a shallow nature and are not traceable in the 1/4° average gravity grids. Spectral analysis of Bouguer anomaly map and 2D gravity modelling of Periyar Plateau region reveal the average depth of the shallow source layer is as shallow as 700-1000 m, which is correlatable with the layer of lateritic/lithomargic soil cover and the underlying weathered country rock having a density of 2.2 g/cc. Such a strong influence on the regional gravity field is due to the wide contrast in the densities of the lateritic cover and the primary rocks of the basement. These results underline the need to recognize the strong influence of such alteration zones on the regional gravity fields, especially the tropics, a factor not always considered.

Three new additions to the earthworm (Clitellata: Megadrili) fauna of Kerala state from the Western Ghats biodiversity hotspot, south-western India

Three new additions to the earthworm (Clitellata: Megadrili) fauna of Kerala state from the Western Ghats biodiversity hotspot, south-western India

Clinical Profile of Infections in the First Year Post Renal Transplantation - A Prospective Cohort Study from a Tertiary Care Hospital in South-western India

Clinical Profile of Infections in the First Year Post Renal Transplantation - A Prospective Cohort Study from a Tertiary Care Hospital in South-western India

Heavy metal load in waters and sediments of Karamana River Basin, southwestern India: A COVID-19 lockdown modulation

Rapid urbanization and industrialization jointly provoked heavy metal contamination in surface water (SW) and channel sediments (CS) of the riverine ecosystem especially in developing countries like India. Water and sediments are to be considered the most vital gears and useful indicators of the level of contamination in an aquatic environment. Furthermore, it is imperative to assess how COVID 19 lockdown, influenced the Karamana River Basin (KRB) waters catering to the quality water needs of urbanites of a city like Thiruvananthapuram, the capital of Kerala. For an insight into this issue, 84 samples (water = 41; sediment = 41) were collected during the pre-monsoon (i.e., January) of 2021 and 2022 and analysed to generate heavy metal concentration levels in the samples. Our estimate of the Heavy Metal Pollution Index (HPI) of water in the KRB in 2021, during the late peak of Covid-19, indicates that though ∼78.89% of the basin (553.78 km2) stayed within the non-contaminated category, and ∼21.11% (or 148.22 km2) was in the contaminated or very poor category. Contrarily, in 2022 after the withdrawal of lockdown restrictions, the non-contaminated area sharply declined to ∼45.04% (316.15 km2) of the basin and the contaminated area rose to 54.96% (385.85 km2). Furthermore, the Inverse Distance Weighted (IDW) modeling strongly supports that Cr and Fe are the leading heavy metal polluters in the Karamana River (KR) waters during 2021 and 2022. Subsequently, estimated Igeo values in sediments indicate that the uncontaminated area has reduced from 88.89% to 83.73%, and the uncontaminated to the moderately contaminated area rose to 5.16%. Therefore, the shutdown of anthropogenic activities, including small- and medium-scale industries as part of the COVID-19 lockdown, improved the surface water quality of KRB for a short-stint of time, but swung back to normality just after the lifting of lockdown restrictions.