Aplysia punctata edit

Life Cycle edit

Spawning occurs in the springtime with warming water temperatures and continues until around October with species tending to only live for approximately one year[1]. Aplysia are simultaneous hermaphrodites with their individual sexual role being determined by either mass or egg-laying specialization[2]. Embryos develop from laid eggs and continue to a larval stage, becoming temporary members of the plankton[3]. Sexual maturity typically occurs within three and four months from birth[3]. Feeding and sexual reproduction both take place upon red algal beds which provide a source of food and protection for Aplysia punctata[1]. Their red-purple coloration comes from the pigments in the red seaweed they feed upon which in turn provides them with camouflage[4].

Sensory Organs & Behavior edit

The rhinophores for Aplysia punctata are located both on their head and posterior tentacle[5]. This is the olfactory organ for the species and it is used to detect pheromones[6]. Auditory and visual information is limited in this animal and so the function of the rhinophore is critical[5]. This chemosensatory action assists in the localization of food and sexual behavior[7]. Amino acids are observed to be an olfactory stimulant to elicit feeding responses[8]. Serotoninergic fibers are also found in the rhinophore nerves which are believed to have a physiological role in olfactory responses to amino acid presence[5]. The glomeruli and the ganglion are segments of the rhinophore which represent different processing stages of sensory information; the processing of odor information takes place in the ganglion[5]. Aplysia have large neurons which make them a model species in the study of the cellular basis of learning and memory[3].

Shell Calcification edit

Aplysia punctata's shell is located internally to protect their heart and other organs. The main element in Aplysia's shell is aragonite that is deposited within a protein matrix.[9] Aragonite is a form of calcium carbonate which notably is susceptible to dissolution in lower sea water pH.[10] Accretionary growth bands may be observed on larger specimens, akin to those seen on the shells of bivalves and other mollusks.[11]

As a species of mollusk, Aplysia punctata performs marine calcification in building and maintaining their shell material.[10] This species of sea hare is unique for its shell resilience in acidified ocean environments.[10] Most marine species with shells (mollusks, echinoderms, corals, coccolithophores, foraminiferans, calcifying algae, etc.) experience increased dissolution[12] and increasing energetic costs of maintaining and growing these structures[13] in this basic environment. However, living in the middle to lower intertidal zone and shallow waters,[14] A. punctata naturally faces fluctuations in pH and has been observed to have no decrease in calcification of new shell material when exposed to acidic environments similar to those of having increased dissolved carbon dioxide.[10]

  1. ^ a b Carefoot, T. H. (1967). "Studies on a sublittoral population of Aplysia punctata". Journal of the Marine Biological Association of the United Kingdom. 47: 335–350.
  2. ^ Pennings, S. C. (1991). "Reproductive behavior of Aplysia californica Cooper: diel patterns, sexual roles and mating aggregations". Journal of Experimental Marine Biology and Ecology. 149: 249–266 – via Elsevier ScienceDirect Journals.
  3. ^ a b c Moroz, L. (2011). "Aplysia". Current Biology. 21: R60–R61 – via Elsevier ScienceDirect Journals.
  4. ^ Kladi, M.; Ntountaniotis, D.; Zervou, M.; Vagias, C.; Ioannou, E.; Roussis, V. (2014). "Glandulaurencianols A–C, brominated diterpenes from the red alga, Laurencia glandulifera and the sea hare, Aplysia punctata". Tetrahedron Letters. 55: 2835–2837 – via Elsevier ScienceDirect Journals.
  5. ^ a b c d Wertz, A.; Roessler, W.; Obermayer, M.; Bickmeyer, U. (2006). "Functional neuroanatomy of the rhinophore of Aplysia punctata". Frontiers in Zoology. 3: 6 – via SpringerLink Journals Complete.
  6. ^ Blumberg, S.; Haran, T.; Botzer, D.; Susswein, A. J.; Teyke, T. (1998). "Pheromones linked to sexual behaviors excite the appetitive phase of feeding behavior of Aplysia fasciata II. Excitation of C-PR, a neuron involved in the generation of appetitive behaviors". Journal of Comparative Physiology A. 182: 785–791 – via SpringerLink Journals Complete.
  7. ^ Audesirk, T. E.; Audesirk, G. J. (1977). "Chemoreception in Aplysia californica—II. Electrophysiological evidence for detection of the odor of conspecifics". Comparative Biochemistry and Physiology- Part A Physiology. 56: 267–270 – via Elsevier ScienceDirect Journals.
  8. ^ Chiken, S.; Kuwasawa, K.; Kurokawa, M.; Ohsuga, K. (2016). "Amino acid-induced reflexes and their neural pathways in an opisthobranch mollusc Pleurobranchaea japonica". Zoological Science. 18: 465–473 – via EBSCOhost Academic Search Premier.
  9. ^ Pedrozo, H. A.; Schwartz, Z.; Dean, D. D.; Harrison, J. L.; Campbell, J. W.; Wiederhold, M. L. (1997). "Evidence for the Involvement of Carbonic Anhydrase and Urease in Calcium Carbonate Formation in the Gravity-Sensing Organ of Aplysia californica". Calcified Tissue International. 61: 247–255 – via SpringerLink Journals Complete.
  10. ^ a b c d Carey, N.; Dupont, S.; Sigwart, J. D. (2016). "Sea Hare Aplysia punctata (Mollusca: Gastropoda) Can Maintain Shell Calcification under Extreme Ocean Acidification". The Biological Bulletin. 231: 142–151.
  11. ^ Usuki, I. (1981). "Growth Characteristics of the Early Juvenile of Aplysia juliana Collected in Winter". Venus (Japanese Journal of Malacology). 39: 212–223.
  12. ^ Orr, J. C.; Fabry, V. J.; Aumont, O.; Bopp, L.; Doney, S. C.; Feely, R. A. (2005). "Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms". Nature. 437: 681 – via Nature.
  13. ^ Dupont, S.; Ortega-Martínez, O.; Thorndyke, M. (2010). "Impact of near-future ocean acidification on echinoderms". Ecotoxicology. 19: 449–462 – via SpringerLink Journals Complete.
  14. ^ Dionísio, G.; Rui, R.; Leal, M.; Cruz, S.; Brandão, C.; Calado, G. (2013). "Beauties and beasts: A portrait of sea slugs aquaculture". Aquaculture. 408–409: 1 – via Eslevier ScienceDirect Journals.