The systematics and evolution of the Sri Lankan rainforest land snail Corilla: New insights from RADseq-based phylogenetics.

The stylommatophoran land-snail genus Corilla is endemic to Sri Lanka and India's Western Ghats. On the basis of habitat distribution and shell morphology, the 10 extant Sri Lankan species fall into two distinct groups, lowland and montane. Here, we use phylogenetic analyses of restriction-site-associated DNA sequencing (RADseq) data and ancestral-state reconstructions of habitat association and shell morphology to clarify the systematics and evolution of Sri Lankan Corilla. Our dataset consists of 9 species of Corilla. Phylogenetic analyses were based on 88 assemblies (9,604-4,132,850 bp) generated by the RADseq assembler ipyrad, using four parameter combinations and different levels of missing data. Trees were inferred using a maximum likelihood (ML) approach. Ancestral states were reconstructed using maximum parsimony (MP) and ML approaches, with 1 binary state character analysed for habitat association (lowland vs montane) and 6 binary state characters analysed for shell morphology (shape, colour, lip width, length of upper palatal folds, orientation of upper palatal folds and collabral sculpture). Over a wide range of missing data (40-87 % missing individuals per locus) and assembly sizes (62,279-4,132,850 bp), nearly all trees conformed to one of two topologies (A and B), most relationships were strongly supported and total branch support approached the maximal value. Apart from the position of Corilla odontophora 'south', topologies A and B showed similar, well-resolved relationships at and above the species level. Our study agrees with the shell-based taxonomy of C. adamsi, C. beddomeae, C. carabinata, C. colletti and C. humberti (all maximally supported as monophyletic species). It shows that C. erronea and C. fryae constitute a single relatively widespread species (for which the valid name is C. erronea) and that the names C. gudei and C. odontophora each apply to at least two distinct, yet conchologically-cryptic species. The MP and ML ancestral-state reconstructions yielded broadly similar results and provide firm evidence that diversification in Sri Lankan Corilla has involved evolutionary convergence in the shell morphology of lowland lineages, with a pale shell and wide lip having evolved on at least two separate occasions (in C. carabinata and C. colletti) from montane ancestors having a dark, narrow-lipped shell.

Characterization of mitochondrial 12S rRNA gene of yellow-striped chevrotain (Moschiola kathygre) and white-spotted chevrotain (Moschiola meminna) and development of a PCR-RFLP marker for the unambiguous identification of the species.

Tragulids hold a significant place in the evolutionary history of mammals since they represent the basal branch of ruminants. Only three genera of tragulids are being extant to date such as Tragulus, Hyemoschus and Moschiola. In the genus Moschiola, Sri Lankan chevrotains (Moschiola meminna and Moschiola kathygre) are endemic to Sri Lanka while Moschiola indica is present in India. Sri Lankan chevrotains lack information on their population structure, distribution and molecular evidence on species identification. This leads to possible threats including habitat destruction, poaching and illegal hunting and trading under different names. In this study, genomic DNA from hair follicles was isolated from M. meminna and M. kathygre and 12S rRNA mitochondrial gene was amplified using universal primers. The PCR products were sequenced and phylogenetic analysis was done on Sri Lankan chevrotains for the first time. The sequences of Sri Lankan chevrotains share 99.7% similarity as they differ only in a single InDel present in M. meminna. In silico analysis of 12S rRNA region revealed that PCR-RFLP approach can be used to differentiate the Sri Lankan chevrotains from Indian chevrotain using the restriction enzymes; Rsa I, Sca I, Hinf I and Hind III. M. kathygre and M. meminna can be differentiated from each other by using Dra I.

Does spatial variation in predation pressure modulate selection for aposematism?

It is widely believed that aposematic signals should be conspicuous, but in nature, they vary from highly conspicuous to near cryptic. Current theory, including the honest signal or trade-off hypotheses of the toxicity-conspicuousness relationship, cannot explain why adequately toxic species vary substantially in their conspicuousness. Through a study of similarly toxic Danainae (Nymphalidae) butterflies and their mimics that vary remarkably in their conspicuousness, we show that the benefits of conspicuousness vary along a gradient of predation pressure. Highly conspicuous butterflies experienced lower avian attack rates when background predation pressure was low, but attack rates increased rapidly as background predation pressure increased. Conversely, the least conspicuous butterflies experienced higher attack rates at low predation pressures, but at high predation pressures, they appeared to benefit from crypsis. Attack rates of intermediately conspicuous butterflies remained moderate and constant along the predation pressure gradient. Mimics had a similar pattern but higher attack rates than their models and mimics tended to imitate the signal of less attacked model species along the predation pressure gradient. Predation pressure modulated signal fitness provides a possible mechanism for the maintenance of variation in conspicuousness of aposematic signals, as well as the initial survival of conspicuous signals in cryptic populations in the process of aposematic signal evolution, and an alternative explanation for the evolutionary gain and loss of mimicry.

Clinico-epidemiology of stings and envenoming of Hottentotta tamulus (Scorpiones: Buthidae), the Indian red scorpion from Jaffna Peninsula in northern Sri Lanka.

In recent years, stings of a lethal scorpion species were recorded from Jaffna Peninsula in the northern dry zone of Sri Lanka. This species was identified as Hottentotta tamulus (Scorpiones: Buthidae) which is the Indian red scorpion commonly found in Maharashtra, India. The Teaching Hospital, Jaffna recorded 84 H. tamulus stings over a year in 2012 and of them, 23 cases provided offending scorpions (proven cases). Three localities in Jaffna were recorded as hotspots of scorpion stings namely Palali, Achchuvali and Karainagar. Of the proven cases, 13 (57%) and 10 (43%) were males and females respectively and had a mean age of 30 years (SD ± 20 years). Among them, 5 (22%) were children below 12 years. In 13 (57%) patients stings occurred inside their houses including two children (40%). Six (26%) stings occurred at night when the victims were in sleep. Median time taken to arrive at the hospital from the time of stinging was 58 min (range 8-550 min). Signs of over activation of autonomic nervous system predominated the clinical picture-tachycardia in 14 (61%), high blood pressure in 11 (48%), excessive sweating in 9 (39%), excessive salivation in 5 (22%), hypotension in 4 (17%) and piloerection in 3 (13%). Children showed higher predilection to develop tachycardia - 4 (80%) and excessive salivation - 3 (60%). Priapism was not observed and 17 (74%) patients have developed intense pain at the site of sting. The commonest ECG change was tachycardia (73%) and occasional T wave inversion. Prazosin as a treatment was given to 22 (96%) patients. All patients made recovery and 13 (57%) patients left the hospital within two days. In future, there is a potential risk of spreading this species to elsewhere in the country and may disturb the ecological balance.