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331-336 Current Status of Researches in Biosciences (2020) : D. K. Mansotra Editor : Prof P.C. Joshi, N Joshi, Reshman Yasmin, and - 110 002 Today & Tomorrow's Printers and Publishers, New Delhi

MEIOTIC CHROMOSOMES OF GARDEN SLVG,LAEVICAULISALTE FROM PRACHI BELT OF RURAL ODISHA, INDIA Badal Das Sc. & Research Laboratory, U.N. Autonomous College of Tech. , Adaspur, Cuttack, Odisha E. mail id: [email protected]

ABSTRACT in the Chromosomal studies in alte was conducted bed of rural laboratory on collection of garden from Prachi River the weighed Odisha. A standardized dose of colchicine was injected to material. prior to dissection of ovotestis to obtain chromatin for the Standardized aceto-orcein squashing technique employed with a diploid purpose recovered several meiotic stages of chromosomes set determined as 2n=34. Haploid chromosome complement observed of 17 under high resolution microscope revealed the arrangement meiosis. bivalents in different micro photographic plates of gonadal in the Spermatogonial metaphase also confirmed the diploid number only species consisting of metacentric & submetacentric configuration as reported earlier Prachi river, KEYWORDS: Chromosomes, Garden slug, Rural area, INTRODUCTION The tropical leatherleaf slug, (Class: Gastropoda, a serious agri­ Order: , Family: ) is & Mandal, 1984) horticultural pest of India and neighboring countries (Raut preliminary where it is invasive (Herbert and Kilburn, 2004). The eco-biology of morphometric studies during laboratory observations of the Odisha (Das & the same species were first reported from coastal belt of 332

Parida, 2015). Chromosomal studies are an informative technique to establish phylogenetic relationship amongst species determining their course of evolution in the kingdom. The first ever account on the description of the karyotypic analysis of the slug Laevicaulis alte was reported from Philippines to confirm its taxonomic position within the family Veronicellidae (Cordova et al. 2010). The present investigation also aims at the chromosomal analysis of the exotic species to account for its taxonomic status as well as analyzing the impact of certain molluscicides in controlling the garden pests in a rural setup. MATERIALS AND METHODS The experimental were collected from the U. N. College garden located on the Prachi river bed of Odisha. Adult species of required length-weight were cultured in specialized rearing tanks constructed for the purpose as well as in laboratory terrarium properly maintained with an artificial environment. Each weighed specimen was injected with 0.02% colchicine (Fig. I) just 24 hours prior to removal of ovotestis meant for chromosomal studies. The dissected gonadal tissue was also undergone hypotonic treatment for 45 minutes using 0.075M KCI and later fixed in freshly prepared aceto-methanol mixture (1 :3) with three changes in it. Now following the standardized aceto-orcein squashing technique (La Cour, 1941 and Stern, 197 5), temporary slides were prepared for examining under 2000x magnification of Microscan B-2 Universal Trinocular research grade microscope using high resolution digital camera with caliper pro software for photographic image analysis of meiotic stages in the species.

Fig.I. Colchicine pretreatment of Laevicau/is a/te with ovotestis exposed for chromosome preparation 333

Fig.2. Photographic plates showing chromosomes of Laevicau/is alte in different stages of gonadal meiosis

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Fig.3. Photographic plates showing chromosomes of Laevicau/is a/te in different stages of gonadal meiosis 334

OBSERVATIONS stages of cells showing The technique described above yields several most frequent stages of meiotic meiotic activity in gonadal tissue. The : Leptotene, Pachytene, Diakinesis, chromosomes were observed as follows , and Telophase-II (Fig.2). The Metaphase-1, Anaphase-1, Anaphase-11 alents in Diakinesis as well as in chromosomes observed to form 17 biv to be 2n=34 as a characteristic Meta phase-I confirming the diploid number was supported by the feature of the species. Such bivalent configuration s with maximum condensation. presence of 17 thick and double structure middle of each chromosome pair The small unstained gaps present in the prominent chiasmatic regions. also proved their bivalent nature showing frequent in occurrence which Spermatogonial metaphase plates were chromosomes exhibiting only revealed a diploid number of 34 small Slug chromosomes at metacentric and submetacentric configuration. of sticking together causing different meiotic stages exhibited a tendency of which the cytogenetic study of chromosomal overlapping as a result gastropod of interest became more difficult. DISCUSSION have greatly increased Chromosome studies in gastropod molluscs & Natarajan (1967), Patterson since the reviews of Burch (1967), Burch et al. (1994), Nakamura (1986) (1969), Patterson & Burch (1978), Nagla latest review the morphological and Thiriot-Quievreux (2002). As per the be identical or very different within features ofgastropod chromosomes may karyotypes may be observed a family. Even within same species different geographical populations or either due to polymorphism among different employed in order to obtain the because differences in the techniques karyotypes include a majority chromosome preparations. Mostly Gastropod following the nomenclature of metacentric and submetacentric chromosomes in Veronicellid, Sarasinu/a of Levan et al. ( 1964) with an exception number of different chromosome linguaeformis (n= 17) possessing equal submetacentric, five subtelocentric morphologies i.e.; four metacentric, four MajoA.D.et.al.1996). The haploid and four telocentric (MajoA.D, 1996 and Laevicaulis alte (n= 17) has already chromosome number in Veronicellid slug (1960) and Majo A.D. (1996) but been reported previously by Natarajan first ever karyotypic analysis of without any karyotypic detail. The Laevicaulis alte were reported Veronicellids like plaebia and karyotype ofSarasinula plaebia with a haploid set to be n= 17. The detailed formis but with a minor difference resembled to that of Sarasinula iinguae five submetacentric, four in chromosome morphology as four metacentric, 335

Another observation acrocentric and four telocentric (Cordova et al. 20 I 0). plebeia from Jammu on meiotic chromosomes of Bean Slug, Saras inula seventeen as specific & Kashmir also reported the haploid complement to be consisting of three in veronicellids but karyotypic differences from earlier and three telocentric metacentric, six submetacentric, five subtelocentric onLaevicaulis configuration (Poonam et al. 2019). The present investigation arrangements alte also supported presence of 17 bivalents in metaphasic in Laevicaulis alte of gonadal meiosis. The first ever karyotypic formula and thirteen has already been described as consisting of only four metacentric (Cordova et al. submetacentric chromosomes in meiotic metaphase-11 of molluscicides 2010). The present investigation emphasizing the impact alte is with a view to on the karyotype of rural garden pest Laevicaulis the inclusion of the support the previous observation as similar considering haploid chromosome species under same family Veronicellidae with the described in earlier number falling within the established range as n 16-18 chromosomal reviews. ACKNOWLEDGEMENTS and Principal The author is extremely thankful to the President GB infrastructural of U.N. Autonomous College for provision of necessary support extended by facilities required for research work with the financial Project. The author UGC, New Delhi under the scheme of Minor Research of India, Kolkata for is highly indebted to the Dµ-ector, Zoological Survey taxonomic identification of the specimen. REFERENCES & Usandivaras, E. M . (1996). The 1. Alderete-D.M, A.M., Mercado, L. A.C. , 1885) (Gastropoda, chromosomes of Sarasinula linguaef ormis (Semper Veronicellidae). Iberus, 14: 155-160. (, Gastropoda) in the 2. Alderete-De Majo, A.M. (1996). The Veronicellidae analysis. lberus, 14: light of new techniques for the karyotype and gametogenesis 147-154. of some Opisthobranchiate 3. Burch, J.B. and Natarajan, R. (1967). Chromosomes ific Science, Vol.XX! (2), 252- mollusks from Eniwetok Atoll, Western Pacific. Pac 259. of some pacific gastropods. Venus: 4. Burch, J.B. (1967). Cytological relationships 25,118-135 Fontanilla I. K. C. (2010). Karyotypic 5. Cordova K. A. T., Batomalaque GA. and (Ferussac, 1821) and Sarasinula Analysis ofTwo Veronicellid Slugs, Laevicaulis alte 3, 17th International plebeia (Fischer, 1868) Tropical Natural History, Supplement of Malacology Congress of Unitas Malacologica, World Congress 336

slug 6. Das,B. and Parida, L. (2015). Morphometric studies of the tropical leatherleaf Laevicaulis alte from prachi belt of Odisha Journal ofEntomology and Zoology Studies 3: 132-134 of eastern 7. Herbert D and Kilburn D. (2004). Field guide to the land snails and slugs South Pietermaritzburg: Natal Museum; Pp 336. Stain Tech. 8. La Cour. L, ( 1941). Aceto-orcein: a new stain-fixative for chromosomes. Vol.16.169-174 centromeric 9. Levan A., Fredga K. and Sandberg A.A., (1964). Nomenclature for position on chromosomes. Hereditas, 52: 201 -220. _, meiosis 10. Nagla, Z. El-Alfy, K.A.Al-Ali and A.H. Abdel-Rehim, (1994). Karyotype J and sperm formation in the land snaii Macrochlamys indica. Qatar Univ. Sci. 14(1),122-128 (Mollusca · 11. Nakamura, H.K. (1986). Chromosomes of Archaeogastropoda y. Prosobranchia) with some remarks on their cytotaxonomy and phylogen Publications of the Seto Marine Biological Laboratory, 31: 191-268. (Mollusca­ 12. Natarajan R., (1960). Further cytologicaf studies in Gastropoda). J Zoo/. Soc. India., 12: 69-79. molluscs. In: 13. Patterson, C.M. and Burch, J.B. (1978). Chromosomes ofpulmonate eds), Pulmonates: Systematics, evolution and ecology, 2A. (V. Fretter & J . Peake, 171-217. Academic Press, New York. of the 2nd 14. Patterson, C.M. (1969). Chromosomes of molluscs. In: Proceedings Symposium of Mollusca, Emakulam, Cochin, India, 2: 635-689. Marine Biological Association of India. chromosome 15. Poonam, Tripathi, N.K. and Kour, P. (2019). First report of meiotic & number and Karyotype analysis of Bean slug, from Jammu Kashmir. Proceedings of 106th Indian Science Congress, Jalandhar, p-369 Laevicaulis 16. Raut, S.K. and Mandal, R.N. ( 1984 ). Natural history of the garden slug alte. Journal ofthe Bengal Natural History Society; 3: 104-105. chromosomes. 17. Stem, E.M. (197 5). A technique for the preparation of gastropod Veliger. 17.296-298 of gastropod 18. Thiriot-Quievreux, C. (2003). Advances in chromosomal studies molluscs. Journal ofMolluscan studies, 69: 187-201