Cylchgronau Cymru

Dyma ni, felly, yn gweld triniaeth arbrofol- ddadansoddol a fu gynt yn nodweddiadol o'r ffisiol- egydd a'r biocemegydd yn dod yn eiddo i'r ecolegwr -a'i astudiaeth yntau o ecoleg weithredol wedi'i chyfoethogi drwy hynny. Cyn gadael y testun, rhaid sôn am un mater sydd yn bwysig a, gwaetha'r modd, yn anochel bellach. Pan gaiff y môr ei halogi gan lygredd cemegol, yr hyn sy'n gofidio ecolegwyr arwynebol yw'r ffaith i lwyth o rywbeth niweidiol gael ei arllwys i'r dwr ac y bydd hynny'n debyg o wenwyno nifer mawr o anifeiliaid a phlanhigion ar unwaith. Er mor bwysig yw hyn, ac er mor ofnadwy yr effeithiau ar adar a physgod a morloi, yr hyn sy'n gofidio'r ecolegydd proffesiynol yw'r effaith ddrwg a geir, efallai, yn 'slei-bach' yn sgil newid cydbwysedd y cymhlethdod cemegol sy'n creu natur arbennig dwr y môr-ac yn enwedig, bellach, yr effaith bosibl ar y 'cawl tenau' hollbwysig. Llyfryddiaeth T. C. Ferguson, 'Utilization of dissolved exogenous nut- rients by the starfishes, Asterias forbesi and Henricia sanguinolenta', The Biological Bulletin, 132 (1967a), 161- 73). T. C. Ferguson, 'An autoradiographic study of the utiliza- tion of free exogenous amino acids by starfishes', The Biological Bulletin, 133 (1967b), 317-29. T. Harris, 'The occurrence of Ophelia bicornis (Polychaeta) in and near the estuary of the River Exe, Devon', Journal of the Marine Biological Association of the U.K., 71 (1991a), 391-402. T. Harris, 'Some aspects of the specific habitat requirements of Ophelia bicornis (Polychaeta)', Journal of the Marine Biological Association of the U.K., 71 (1991 b), 771-86. T. Harris, 'The rectal organ of Ophelia bicornis Savigny (Polychaeta): a device for efficient defaecation', Zoological Journal of the Linnean Society, 103 (1991c), 197-206. H. W. Harvey, Recent advances in the Chemistry and Biol- ogy of sea water (Gwasg Prifysgol Caergrawnt, 1945). A. V. Ivanov, 'New Pogonophora from far Eastern scas' Systematic Zoology, 3 (1954), 69- 79., A. V. Ivanov, 'Pogonophora', Systematic Zoolog, 4 (1955), 170-8. C. B. Jørgensen, 'August Pütter, August Krogh, and mod- ern ideas on the use of dissolved organic matter in aquatic environments', Biological Reviews of the Cambridge Phiì osophical Society, 51 (1976), 291-328. N. O. G. Jørgensen, K. Mopper a P. Lindroth, 'Occurrence origin, and assimilation of free amino acids in an estuarine environment', Ophelia, Atodiad 1 (1980), 179-92. C. Little a B. L. Gupta, 'Pogonophora: uptake of dissolved nutrients', Nature, London, 218 (1968), 873-4. C. Little a B. L. Gupta, 'Studies on Pogonophora. III. Uptake of nutrients', Journal oJExperimental Biology', 51 l (1969), 759-73. E. Péquignat, '"Skin digestion' and epidermal absorption in irregular and regular urchins and their probable relation to the outflow of spherule-coelomocytes', Nature, London 210 (1966), 397-9. E. Péquignat, 'Some new data on skin-digestion and absorption in urchins and sea-stars (Asterias and Hen- ricia)\ Marine Biology, 12 (1972), 28-41. A. Pütter, Die Ernährung der Wassertiere und der Stoffhaushalt der Gewässer (Fischer, Jena, 1909), 323tt. A. J. Southward ac E. C. Southward, 'Dissolved organic matter and the nutrition of the Pogonophora: a reassess- ment based on recent studies of their morphology and biol- ogy', Kieler Meeresjorschungen, 5 (1981), 445-53. E. C. Southward ac A. J. Southward, 'A preliminary account of the general and enzyme histochemistry of Siboglinum atlanticum and other Pogonophora', Journal of the Marine Biological Association of the U.K., 46 (1966), 579-616. G. C. Stephens a R. A. Virkar, 'Uptake of organic material by aquatic invertebrates. IV. The influence of salinity on the uptake of amino acids by the brittle star, Ophiactis arenosa', The Biological Bulletin, 131 (1966), 172-85. M. G. Stewart, 'The uptake and utilization of dissolved amino acids by the bivalve Mya arenaria (L)', yn D. S. McLusky ac A. J. Berry, (gol.), Physiology and Behaviour of Marine Organisms (Gwasg Pergamon, Rhydychen, 1978), 165-76.