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Presentation on theme: "SEASONAL PATTERNS AND MOLLUSK REPRODUCTION Ashlyn Giddings."— Presentation transcript:


2 MOLLUSCA Variety of reproductive strategies and life cycles Mostly dioecious with some species hermaphroditic External or internal fertilization (UCMP, 2006; UCMP, 2001) (Cob, 2013)

3 DIFFICULTIES IN STUDYING SEASONAL REPRODUCTION IN THE OCEAN Difficulty in witnessing spawning events Individual seasonal reproduction may be obscured at the population level (Eckelbarger, 1995) Seasonal patterns can vary with location, even within a species (Lourenço et al, 2012) (Wikipedia, 2007a)

4 PHOTOPERIOD Photoperiod is the length of daylight Can be a seasonal indicator in species in the euphotic zone (Hodgson, 2010) Photoperiod can influence juvenile survival (Koueta, 2003) Example: Sepia officinalis L. (Koueta, 2003) (Wikipedia, 2007b)

5 WATER TEMPERATURE Warmer water = reproduction (Hodgson, 2010; Wayne, 2001) Examples: Aplysia californica (Wayne, 2001) (Wikipedia, 2004)

6 FOOD AVAILABILITY Food availability triggers oogenesis or signals that conditions are optimal for larval development (Eckelbarger, 1995) Example: Aulacomya ater (Hodgson, 2010) (WoRMS, 2013)

7 EVOLUTIONARILY CONSERVED Ancestral breeding patterns may be conserved independent of local conditions (Hodgson, 2010) Deep sea species likely retain seasonal patterns in reproduction (Eckelbarger, 1995) Example: Helcion spp. (Hodgson, 2010) (Poppe, 2003)

8 HUMAN IMPACTS Climate change- increased temperature can have deleterious effects on Mollusks (Kirby et al, 2008) Plasticizers (Phthalates and Bisphenol A)- Mollusks appear very sensitive (Oehlmann et al., 2009) Estrogenic chemicals (Bisphenol A, etc) stimulate egg production at low doses/inhibit at higher doses (Jobling et al., 2003) (Wikipedia, 2006)

9 Sources Cob, G. Taxonomy. day/collections/our-collections/glaucus-atlanticus/taxonomy/index.html 2013-04-20 Eckelbarger, K., L. Watling. 1995. Role of phylogenetic constraints in determining reproductive patterns in deep-sea invertebrates. Invertebrate Biology 114(3): 256-269 Hodgson, A. 2010. Reproductive seasonality of southern African inshore and estuarine invertebrates – a biogeographic review. African Zoology 45(1): 1-17 Jobling, S. D. Casey, T. Rodgers-Gray, J. Oehlmann, U. Schulte-Oehlmann, S. Pawlowski, T. Baunbeck, A.P. Turner, C.R. Tyler. 2003. Comparative responses of molluscs and fish to enviromental estrogens and an estrogenic effluent. Aquatic Toxicology 65(2): 205-220 Kirby, P.R., G. Beaugrand, J.A. Lindley. 2008. Climate-induced effects on the meroplankton and the benthic-pelagic ecology of the North Sea. Limnology and Oceanography 53(5): 1805-1815 Koueta, N., E. Boucaud-Camou. 2003. Combined effects of photoperiod and feeding frequency on survival and growth of juvenile cuttlefish Sepia officinalis L. in experimental rearing. Journal of Experimental Marine Biology and Ecology 296(2): 215-226 Lourenço, S., A. Moreno, L. Narciso, Á. F. González, J. Pereira. 2012. Seasonal trends of the reproductive cycle of Octopus vulgaris in two environmentally distinct coastal areas. Fisheries Research. 127–128: 116-124

10 Oehlmann, J., U. Schulte-Oehlmann, W. Kloas, O. Jagnytsch, I. Lutz, K.O. Kusk, L. Wollenberger, E.M. Santos, G. C. Paull, K. J. W. Van Look, C. R. Tyler. A critical analysis of the biological impacts of plasticizers on wildlife. Phil. Trans. R. Soc. B 236(1526): 2047-2062 Poppe, G. 2003. Helcion (Helcion) pectunculus. 2013-04-20 WoRMS. 2013. Aulacomya atra. 2013-04-20 University of California Museum of Paleontology (UCMP), 2001. The Bivalvia. 2013-04-20 University of California Museum of Paleontology (UCMP), 2006. The Cephalopoda. 2013-04-20 Wayne, N. 2001. Regulation of seasonal reproduction in mollusks. Journal of Biological Rhythms 16(4): 391-402 Wikipedia 2004. File:Aplysia californica.jpg 2013-04-18 Wikipedia 2006. File:Mudsnail2.jpg 2013-04-20 Wikipedia 2007a. File:Octopus vulgaris 3.JPG 2013-04-20 Wikipedia 2007b. File:Kalamar.jpg 2013-04-20 Sources


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