Open Marine Course: Functional Morphology and Evolutionary Biology of Marine Invertebrates

[Textbook in this course]

Animals are classified into 30-35 phyla, most of which are so-called ginvertebratesh, animals without backbones (= vertebral column). Many groups of invertebrates are aquatic, and the all members in the 14 phyla are exclusively marine. Marine invertebrates exhibit a wide range of sizes and their body plans are highly diverse.

Each body plan has been evolved in close relationships with lifestyle concerning locomotion, feeding, protection from predators, and reproduction.

The aim of this course is to learn body plans of diversified marine invertebrates by sketching and to understand and discuss relationship between the morphology and evolution or function.

(»Overview and Application)
(»In Japanese)

  • Field sampling

    [Sampling at Bansho-zaki]

    Intertidal zones provide various habitats to invertebrates. Bansho-zaki, the rocky and boulder shore near the Seto Marine Biological Laboratory, faces the Pacific Ocean, highly influenced by the warm current Kuroshio on both marine and terrestrial climates. A variety of cnidarians, annelids, molluscs, arthropods, and echinoderms are found in tidepools and under boulders.

  • Comparative anatomy of crustaceans

    [Dissection of a hermit crab]

    Crustaceans (phylum Arthropoda) are highly diversified in marine environment. By dissecting hermit crabs (decapods, under water), wharf roaches (isopods, semi-terrestrial), and stalked barnacles (cirriped, sessile), we learn diversity of the metamerism (segmentation) and examine degree of specialization of appendages in each metamere in terms of their function.

  • Comparative anatomy of gastropods

    [Observation of limpet teeth]

    Gastropods (phylum Mollusca) are also highly diverse and display wide range of feeding habits, such as grazing on periphytic microalgae and seaweeds, preying on bivalves, gastropods, and fishes, and filtering out and consuming planktons, depending on the taxonomic group. By dissecting intertidal gastropods, we learn how the different feeding habits relate to morphology of internal organs, such as radula.

  • Comparative anatomy of polychetes

    [Onboard sampling of polychaetes]

    Polychaetes (phylum Annelida) also exhibit the metamerism, in which all the metameres are similar with a little specialization. However, the morphology of appendages is different between free-living species and sessile species. By dissecting free-living interstitial species and sessile species, we learn how the different lifestyles relate to the morphology of appendages.