Lecture 3

• CNIDARIA ANTHOZOA Key features/characteristics• Sea anemones – solitary.• Hard corals and soft corals – colonial.• No medusa stage in development – adults almost all attached to seabed, in polyp form.• Two main subclasses:

  – Hexacorallia = 6-fold symmetry (hard corals, sea anemones, tube anemones, zoanthids)– Octocorallia = 8-fold symmetry (soft corals, gorgonians [sea pens, fans, and whips], and sea pansies)
• Stinging cells are used for self defence and aggressive behaviour -> competition for space and food will lead to this sort of behaviour
• Anemonia viridis (snakelocks anemone)CNIDARIA ANTHOZOA HEXACORALLIA ACTINIARIA

  Intertidal in the Atlantic and Mediterranean Sea.• ‘Greenness’ of tentacles depends on the host and symbiont pigments.• Symbiont algae require sunlight!

  Tend to find them in the intertidal region/lower intertidal region on the rocky shore -> find them on rocks underneath boulders and crevices

  Tends to be subtotal -> found un shallow subtidal regions
• GFPs -> green fluorescent proteins
• CNIDARIA ANTHOZOA HEXACORALLIA ACTINIARIA

  Sexual reproduction by broadcast spawning• Maternal inheritance of symbionts (Symbiodiniaceae)• Pelagic “planula” larvae
• Mouth Asexual reproduction by longitudinal fission (clone formation)Anemonia viridis (snakelock anemone)
• Variety of different colonising formations and in numerous different colours.• Individual polyps attached by stolon or colonial mats.• Distinguished by incorporating sand and other small material into tissue to help make structure.• Marginal tentacles.• Most propagate asexually, with offspring remaining attached to original polyp.
• Variety of different colonizing formations and in numerous different colours.• Individual polyps attached by stolon or colonial mats.• Distinguished by incorporating sand and other small material into tissue to help make structure.• Marginal tentacles.• Most propagate asexually, with offspring remaining attached to original polyp.
• Soft corals, gorgonians (sea pens, fans, and whips).• Sclerites = tiny, spiny skeletal elements – provide some support.• Gorgonin = flexible, horny, protein-substance in Gorgonians• Thrive in nutrient-rich waters with low light
• Most easily recognisable by the tube!• Solitary, buried in soft sediments.• Multiple polyps per tube!

  Have quite large surface area

  
• corals can be used for jewellery

  jellyfish can be used as fine dining
• Soft coral (sea plume) from Caribbean Sea.• Commercially important – harvested for bioactive compounds used in pharmaceutical industry and cosmetics.• Pseudopterosin A: Anti-inflammatory substance to treat pain, discovered by W. Fenical.
• Molecular biomarkers – for fluorescence biological imaging• GFP-homologous proteins with green and red fluorescence• Non-fluorescent chromoproteins• ~18% identical amino acids compared to GFP
• UsesCNIDARIA

  Molecular biomarkers – for fluorescence biological imaging• GFP-homologous proteins with green and red fluorescence• Non-fluorescent chromoproteins• ~18% identical amino acids compared to GFP
• Importance of CNIDARIA-

  Reef building corals are used as:• Medical implants (e.g., bone reconstruction)• Building material• Cement production• Ornamental trade• Souvenir trade