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            | Phyllid 
            nudibranchs Family Phyllidiidae
 updated 
            Apr 2021
 Where 
            seen? These nudibranchs with tough skin are often encountered, 
            especially on our Southern shores, among coral rubble and on reefs. 
            It is believed that these nudibranchs are commonly seen because they 
            can roam around in the open with impunity due to the nasty stuff they 
            secrete to deter predators. Their colourful patterns probably also 
            warn of this feature.
 
 What are phyllid nudibranchs? Phyllid nudibranchs are thick slugs with a body covered in warts or 
            bumps. They don't have flower-like gill structures on their backs. 
            The gills are hidden under the mantle skirt and are made up of a row 
            as many as 100 leaflets, along the length of the body on either side 
            of the foot. Their short rhinophores are often overlooked among all 
            the bumps on their bodies. The different genus are identified by the 
            position of the anus (in the middle of its back for Phyllidia species), and shape of the oral tentacles.
 
 What do they eat? Phyllids eat sponges. They lack a 
            radula and don't rasp the sponge. Instead, digestive juices are secreted 
            into the sponge and the partially digested sponge is sucked up. Sort 
            of like a sponge slurpee. Some species may insert a large feeding 
            organ called the pharyngeal bulb deep into the sponge to eat it.
 
 Members of the Family Phyllidiidae absorb the toxic chemicals in their 
            sponge food and incorporate these chemicals in their own defence. 
            They produce a milky white substance. This is lethal to other nudibranchs 
            especially if they are kept in the same tank.
 
 Human uses: Although colourful, 
            phyllids are not popular in the aquarium trade as they produce a powerful 
            toxin that can kill off the entire tank. The toxins produced are so 
            strong that the water from the aquarium may have an acrid smell. The 
            properties of these toxins are currently being studied for possible 
            applications such as in human medicine and anti-fouling uses.
 |  
         
          |  Black 
              phyllid: milky substance secreted when disturbed.
 Sisters Island, May 07
 |  Short rhinophores 
              of the Varicose phyllid look like the orange blobs on its body.
 St. John's Island, May 05
 |  Gills on the 
              underside along 
              the length of the body
 St. John's Island, Jan 06
 |  
 
        
          
            | Some Phyllid nudibranchs on Singapore shores |  
 
 
 
        
          
            | More Phyllid nudibranchs on Singapore shores |  
 
        
          |  Phyllidia elegans
 Pulau Hantu, Apr 21
 Photo shared by Jianlin Liu on facebook.
 |  Phyllidia elegans (underside) |  |  
 
         
          | Links References
 
 
               J. van Alphen, 
                N. J. de Voogd and B. W. Hoeksema Differential 
                feeding strategies in phyllidiid nudibranchs on coral reefs at 
                Halmahera, northern Moluccas Coral Reefs Volume 30, Number 
                1 (2011), 59.Debelius, 
                Helmut, 2001. Nudibranchs 
                and Sea Snails: Indo-Pacific Field Guide IKAN-Unterwasserachiv, Frankfurt. 321 pp.Wells, Fred 
                E. and Clayton W. Bryce. 2000. Slugs 
                of Western Australia: A guide to the species from the Indian to 
                West Pacific Oceans . 
                Western Australian Museum. 184 pp.Coleman, 
                Neville. 2001. 1001 
                Nudibranchs: Catalogue of Indo-Pacific Sea Slugs. Neville 
                Coleman’s Underwater Geographic Pty Ltd, Australia.144pp.Coleman, 
                Neville, 1989. Nudibranchs 
                of the South Pacific Vol 1. 64 pp. |  |  |