SEASONAL
PATTERNS AND
MOLLUSK
REPRODUCTION
Ashlyn Giddings
MOLLUSCA
• Variety of reproductive
strategies and life cycles
• Mostly dioecious with some
species hermaphroditic
• External or internal fertilization
(UCMP, 2006; UCMP, 2001)
(Cob, 2013)
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)
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)
WATER TEMPERATURE
• Warmer water = reproduction
(Hodgson, 2010; Wayne, 2001)
• Examples: Aplysia californica
(Wayne, 2001)
(Wikipedia, 2004)
FOOD AVAILABILITY
• Food availability triggers
oogenesis or signals that
conditions are optimal for larval
development (Eckelbarger, 1995)
• Example: Aulacomya ater
(Hodgson, 2010)
(WoRMS, 2013)
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)
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)
Sources
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Cob, G. Taxonomy. http://www.nhm.ac.uk/nature-online/species-of-theday/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
Sources
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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.
http://www.gastropods.com/7/Shell_15697.shtml 2013-04-20
WoRMS. 2013. Aulacomya atra. http://www.marinespecies.org/aphia.php?p=image&pic=65426
2013-04-20
University of California Museum of Paleontology (UCMP), 2001. The Bivalvia.
http://www.ucmp.berkeley.edu/taxa/inverts/mollusca/bivalvia.php 2013-04-20
University of California Museum of Paleontology (UCMP), 2006. The Cephalopoda.
http://www.ucmp.berkeley.edu/taxa/inverts/mollusca/cephalopoda.php 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
http://en.wikipedia.org/wiki/File:Aplysia_californica.jpg 2013-04-18
Wikipedia 2006. File:Mudsnail2.jpg http://en.wikipedia.org/wiki/File:Mudsnail2.jpg 2013-04-20
Wikipedia 2007a. File:Octopus vulgaris 3.JPG
http://commons.wikimedia.org/wiki/File:Octopus_vulgaris_3.JPG 2013-04-20
Wikipedia 2007b. File:Kalamar.jpg http://en.wikipedia.org/wiki/File:Kalamar.jpg 2013-04-20