ASSOCIATIONS 611 



TABLE 14.1 



Examples of Marine Animals Containing Algal Symbionts 

 (zoochlorellae and zooxanthellae) 

 Protozoa 



Rhizopoda : Foraminifera : Trichosphaerium, Peneroplis, Orbitolites, Globigerina 

 Radiolaria: Collozoum, Sphaerozoum, Thalassicolla, Lithocercus, Acanthometra, 



Heliosphaera and many others 

 Mastigophora: Noctiluca miliaris, Leptodiscus medusoides 



Ciliophora: Spatostyla sertulariarum, Scyphidia scorpaenae, Trichodina patellae, 

 Mesodinium rubrum, Frontonia leucas, Vorticella, Cothurnia 



Coelenterata 



Hydrozoa: Hydroida: Halecium, Hydrichthella, Sertularella, Aglaophenia 

 Hydrocorallinae : Millepora, Sporadopora 

 Siphonophora : Velella, Porpita 

 Scyphozoa : Cassiopeia, Catostylus, Cotylorhiza, Mastigias et al. 

 Anthozoa: Alcyonaria: Lobophytum, Sclerophytum, Xenia, Heteroxenia, Sarco- 



phyton, Gorgonia, Virgularia, Alcyonium (tropical species), 

 Heliopora et al. 

 Antipatharia: Stichopathes, Hillopathes, Eucirripathes 

 Actiniaria: Anemonia sulcata, Actinia bermudensis, Anthopleura balii, 

 Aiptasia diaphana,A. couchii, Cribrina xanthogrammica et al. 

 Zoanthinaria: Parazoanthus, Zoanthus, Zoanthella, Zoanthina, Isaurus 

 Madreporaria : Abundant in nearly all shallow water corals except 

 Astrangia and Phyilangia 



Platyhelminthes 



Turbellaria: Convoluta, Amphiscolops, Monocelis, Enterostomum 



Annelida 



Polychaeta : Eunice gigantea 



Mollusca 



Gastropoda: Aeolidiella glauca, Tridachia crispata, Doridoedes gardineri, Melibe 



rangii, Spurilla neopolitana, Phyllirrhoe bucephala, Placobranchus 



ocellatus 

 Lamellibranchia: Tridacna, Hippopus, Corculum 



Bryozoa (?) 



Zoobothryon, Bicellaria 



Tunicata 



Diplosoma virens, Didemnum viride, Trididemnum cyclops 



(Based on Buchner (12), with additions) 



activity (6, 95). The animals hosts will be reviewed in order before describ- 

 ing some general features of algal-animal symbiotic relationships. 



Protozoa. Numerous Radiolaria contain symbiotic zooxanthellae. 

 Generally, the algal cells are localized in the extracapsular protoplasm 

 (sub-orders Spumellaria, Nassellaria) but in Acanthometra (sub-order 

 Acantharia) they are intracapsular in position (Fig. 14.18.) The Phaeodaria, 

 which lack yellow cells, are deep-sea forms. The colonial forms, in parti- 

 cular, feed holozoically only when they are young and algal symbionts 

 are few. Symbionts are absent from young individuals, which must be 

 reinfected anew by free-living motile cells. 



In a similar manner, many foraminifers have formed close associations 

 with unicellular algae, e.g. Orbitolites. These may be extremely abundant, 

 as many as 100,000 algal cells having been found in a large specimen of 

 Peneroplis. Polythalamian foraminifers exist in two forms, microspheres 



