Diversity and guild structure of spiders in poyya pokkali rice agroecosystem, a range disjunct landscape in Thrissur, Kerala, India
Sunish E (91717011)
Diversity and guild structure of spiders in poyya pokkali rice agroecosystem, a range disjunct landscape in Thrissur, Kerala, India - MPhil EI 2017-2018
Background: Spiders play a very significant role in ecology by being exclusively
predatory and thereby regulate insect populations. In India, Arachnology is still in its
infancy compared with the breadth and depth of entomological research. Spiders
represent a diverse and functionally important group of arthropods and the assessment
of their status can provide much information useful in monitoring the integrity of
biotic communities. The pokkali rice is a nutrient rich saline resistant variety of rice
cultivated along the coastal ares of Thrissur, Alappuzha and Ernakulam district of
Kerala. A pioneering study was conducted to document the spider diversity associated
with Poyya pokkali rice agroecosystems of Thrissur district. Additionally an attempt
was also made to characterize the cytochrome oxydase C subunit 1 (CO1) of salticid
spider, Phintella vittata (C.L. Koch, 1846) based on spiders collected from four
districts of Kerala.
Methods: Extensive faunistic surveys of spiders in altitudinally different sites of
Poyya Grama Panchayath was carried out for four months form December, 2017 to
March, 2018. Spiders collected from different quadrates by hand picking and
sweeping methods once in a week. The spiders collected were arranged into different
functional groups or guilds, according to their ecological characteristics relating to
foraging manner. Diversity indices were calculated. For molecular studies, spiders
preserved in absolute alcohol and sequencing of DNA of different individuals of
Phintella vittata using universal markers were carried out and p-distance analysis and
Maximum Likelihood Trees were prepared.
The Results: A total of 5,213 individuals belonging to 76 species coming under 50
genera and 20 families were collected and dealt with. A mygalomorph species
Annandaliella ernakulamensis was also reported. Twenty eight species are reported as
endemic to India. Field photographs and microphotographs are provided. A checklist
is prepared on collected spiders and arranged them into seven feeding guilds based on
their foraging mode. The diversity indices analysis of spiders was also performed and
it varies among different sites and most diverse sampling locality was found to be
Chenthurunni with a value of 3.54 and 0.95 for Shannon-Weiner and Simpson Indices
respectively, shows a stable ecosystem. The p-distance value obtained among the spiders
collected from different localities was found to be trivial, though a positive
correlation with the geographic distance and genetic distance could be established.
Conclusion: Being lied in the Western Ghats, the Poyya Pokkali rice agroecosystem
was hypothesised to possess a rich and diverse araneofauna. This hypothesis are
satisfied by the outcome of this study. In fact, this scanty effort represents only a
splinter of the fauna of Poyya pokkali rice fields. As this region with diverse climates
and natural background, further investigations will certainly reveal many more
species of spiders. The present study envisaged an in-depth study of the diversity and
feeding behaviour of spiders of this biodiversity hotspot and shed some effort to bring
this otherwise neglected animal group onto the conservation radar screen. The
molecular study was carried out using two universal primers, hence the confinement
in modest use of primers may also one of the reason s for the less divergence among
spider individuals studied. Nevertheless, the results from this analysis have improved
our understanding of intra-specific relationships among the spiders.
Keywords: Spider diversity, Phintella vittata, p-distance, Guilds, Pokkali rice, Thrissur, Kerala , India.
SPIDER DIVERSITY
PHINTELLA VITTATA
P-DISTANCE
GUILDS
POKKALI RICE
THRISSUR
KERALA
INDIA
Diversity and guild structure of spiders in poyya pokkali rice agroecosystem, a range disjunct landscape in Thrissur, Kerala, India - MPhil EI 2017-2018
Background: Spiders play a very significant role in ecology by being exclusively
predatory and thereby regulate insect populations. In India, Arachnology is still in its
infancy compared with the breadth and depth of entomological research. Spiders
represent a diverse and functionally important group of arthropods and the assessment
of their status can provide much information useful in monitoring the integrity of
biotic communities. The pokkali rice is a nutrient rich saline resistant variety of rice
cultivated along the coastal ares of Thrissur, Alappuzha and Ernakulam district of
Kerala. A pioneering study was conducted to document the spider diversity associated
with Poyya pokkali rice agroecosystems of Thrissur district. Additionally an attempt
was also made to characterize the cytochrome oxydase C subunit 1 (CO1) of salticid
spider, Phintella vittata (C.L. Koch, 1846) based on spiders collected from four
districts of Kerala.
Methods: Extensive faunistic surveys of spiders in altitudinally different sites of
Poyya Grama Panchayath was carried out for four months form December, 2017 to
March, 2018. Spiders collected from different quadrates by hand picking and
sweeping methods once in a week. The spiders collected were arranged into different
functional groups or guilds, according to their ecological characteristics relating to
foraging manner. Diversity indices were calculated. For molecular studies, spiders
preserved in absolute alcohol and sequencing of DNA of different individuals of
Phintella vittata using universal markers were carried out and p-distance analysis and
Maximum Likelihood Trees were prepared.
The Results: A total of 5,213 individuals belonging to 76 species coming under 50
genera and 20 families were collected and dealt with. A mygalomorph species
Annandaliella ernakulamensis was also reported. Twenty eight species are reported as
endemic to India. Field photographs and microphotographs are provided. A checklist
is prepared on collected spiders and arranged them into seven feeding guilds based on
their foraging mode. The diversity indices analysis of spiders was also performed and
it varies among different sites and most diverse sampling locality was found to be
Chenthurunni with a value of 3.54 and 0.95 for Shannon-Weiner and Simpson Indices
respectively, shows a stable ecosystem. The p-distance value obtained among the spiders
collected from different localities was found to be trivial, though a positive
correlation with the geographic distance and genetic distance could be established.
Conclusion: Being lied in the Western Ghats, the Poyya Pokkali rice agroecosystem
was hypothesised to possess a rich and diverse araneofauna. This hypothesis are
satisfied by the outcome of this study. In fact, this scanty effort represents only a
splinter of the fauna of Poyya pokkali rice fields. As this region with diverse climates
and natural background, further investigations will certainly reveal many more
species of spiders. The present study envisaged an in-depth study of the diversity and
feeding behaviour of spiders of this biodiversity hotspot and shed some effort to bring
this otherwise neglected animal group onto the conservation radar screen. The
molecular study was carried out using two universal primers, hence the confinement
in modest use of primers may also one of the reason s for the less divergence among
spider individuals studied. Nevertheless, the results from this analysis have improved
our understanding of intra-specific relationships among the spiders.
Keywords: Spider diversity, Phintella vittata, p-distance, Guilds, Pokkali rice, Thrissur, Kerala , India.
SPIDER DIVERSITY
PHINTELLA VITTATA
P-DISTANCE
GUILDS
POKKALI RICE
THRISSUR
KERALA
INDIA