AGLAOPHENID HYDROIDS AND THEIR LI'ITORAL ENVIRONMENT IN KEPPEL BAY, QUEENSLAND Barry Eric Bryant Thesis suhnitted for the degree of Master of Science, University of New South Wales. June, 1986. I hereby certify that this work has not been sul:mitted for a higher degree to any other University or Institution • Barry Eric Bryant I hereby declare that this thesis is my own work and that, to the best of my knowledge and belief, it contains no material previously published or written by another person nor material which to a substantial extent has been accepted for the award of any other degree or diploma of a university or other institute of higher learning, except where due acknowledgement is made in the text of the thesis. Barry Eric Bryant TABLE OF CONTENTS List of figures. List of Tables. List of Appendices. Page Sumnary 1. Introduction 1 2. Study Area 7 2.1 General 7 2.2 Topography 7 2. 3 Drainage 7 2.4 Climate 8 3. Study Sites 8 4. Hydrology 9 4.1 Sea Temperature 9 4.1.1 Technique 9 4.1.2 Results-Keppel Bay 10 4.1.3 Heron Island 10 4.2 Salinity 11 4.2.1 General 11 4.2.2 Technique 11 4.2.3 Discussion 12 5. Taxonany 14 Aglaophenia cupressina Lam. 1816 14 Halicornaria hians Busk 1852 18 Lytocarpus philippinus (Kirch.1872) 22 L.phoeniceus (Busk 1852) 25 Thecocarpus angulosus (Lam.1816) 28 6. Minor Survey Sites 30 6.1 Punpkin Island 30 6.2 Fitzroy River Estuary 32 6.3 Statue Bay 32 6.4 wave Point 33 6.5 Emu Park Beach 33 6.6 North-West Island 35 7. Major Study site:Ritamada Headland 36 8. Biology 37 8.1 Introduction 37 8.2 Environmental Tolerance 37 8.2.1 Exposure 37 8.2.2 wave Action 39 8.2.3 Shade 40 8.2.4 Spatial Orientation 41 8.3 Substrate 43 8.6 Growth 45 8.4.1 Colony Growth and Branching 45 8.4.2 Stolons 46 8.4.3 Regression 47 8.5 Reproduction 47 8.5.1 General 47 8.5.2 Regeneration and Stolonisation 48 8.5.3 Discussion 49 8.6 Nematocysts and Stinging Potential 52 8.6.1 Nematocysts of L.philippinus 52 8.6.2 Stin:Jing Potential 54 Conclusions 58 Acknowledgements 62 References 67 Appeooices 80 ----LIST OF FIGURES Facing Page Fig. 2.1 Central Queensland Coastline 7 3.1 Keppel Bay study sites. 8 3.2 Exposure of Keppel Bay study sites. 8 4.1 Mean rronthly sea temperature and range in Keppel Bay. 10 4.2 Yearly variation in mean sea surface temperature for Townsville, Keppel Bay and Moreton Bay. 10 5.1 Growth habit of A.cupressina. 15 5.2 A.cupressina - hydrothecal structures. 15 5.3 Growth habit of H.hians. 19 5.4 H.hians - hydrothecal structures. 19 5.5 Growth habit of L.philippinus. 23 5.6 L.philippinus - hydrothecal structures. 23 5.7 Growth habit of L.phoeniceus. 26 5.8 L.phoeniceus - hydrothecal structures. 26 5.9 Growth habit of T.angulosus. 29 5.10 T.angulosus - hydrothecal features. 29 5.11 T.angulosus - hydrothecal and sarcothecal features. 30 6.1 Pumpkin Island Survey Site 30 6.2 Fitzroy River Survey Site. 32 6.3 Statue Bay Survey Site. 32 6.4 Wave Point Survey Site. 33 6.5 Emu Park Survey Site. 33 6.6 North-West Island Survey Site. 35 7.1 Ritamada Survey Site. 36 7.2 Keppel Bay offshore profiles 36 7.3 Relationships of rock strata to wind and wave directions at Ritamada. 37 8.1 Percentage exceedance distribution of water levels under tidal influence-Keppel Bay. 38 8.2 Time of monthly Lowest Low Water related to mean monthly temperatures - Keppel Bay 39 8.3 Orientation of rock strata and the position of site types of hydroid location. 39 8.4 Sites of attachnent of aglaophenid colonies to rocky substrates. 41 8.5 Attachnent of branches and hydrocladia of L.philippinus. 43 8.6 Morphology of aglaophenid branching 45 8.7 Nematophores and discharged mastigophores of L.philippinus. 52 8.8 Nematocysts of L.philippinus 53 8.9 Tentacular nematocysts (atrichous isorhizas) of L.philippinus 53 8.10 Sea temperature and aglaophenid stinging potential. 56 -------LIST OF TABLES Facing Page Table 4.1 Maximum and minimum surface sea temperatures in Keppel Bay, 1980-1984. 10 8.1 Distribution of L.philippinus by site types. 40 8.2 Length of main stem of L.phillipinus in relation to degree of branching. 46 8.3 Published records of fertile colonies of aglaophenid species found in Keppel Bay. 48 LIST OF APPENDICES Appendix I L.philippinus: lengths of main stem and first order branch in specimens bearing only first order branches. Apperrl ix II L.philippinus: lengths of main stem, longest first and second order branches in specimens bearing two orders of branching. Appendix II I Definition of clinical terms used in Section 8.8. Apperrlix IV Table of Salinity Values in Keppel Bay February 1982 to June 1984. Apperrlix V Sedimentation in Keppel Bay. SUMMARY Intralittoral Keppel Bay species of aglaophenid hydroids (well­ known but rarely investigated causes of hunan injury) have been identified, aspects of their biology investigated and related to hitherto unpublished envirormental data. New records for Keppel Bay of L.phoeniceus, H.hians and T.angulosus are reported and the presence of L.philippinus confinned. Mean sea temperatures range fran 19.lC in June or July to 29.3C in January or February. Salinities range fran 25%0 to 42%0 fluctuating with seasonal evaporation and precipitation patterns and run off. Hydroids occur seawards of mid-tide level. Colonies occur on gorgonian and rocky substrates in tidal pools below residual water level. At ELWS level, colonies tolerate an annual exposure of 3%. Heavier colonisation occurs on the sheltered aspect of rocks and on sites offering minimum sedimentation and maximum trophic opportunity, especially the upper edges of rocks and on dead protruding remnants of gorgonian stems. Surveys suggest that sexual reproduction is of little significance littorally due to envirormental stress and that larval recruitment occurs fran offshore stocks. Asexual reproduction fran a persistent stolon is a major means of colonisation. The presence of atrichous isorhizas (glutinants) and micro-basic mastigophores is demonstrated. Hunan stings caused by the latter nematocysts characteristically show delayed rather than inmediate urticaria, pruritus arrl vesiculation. A seasonal variation in virulence of both L.philippinus and L.phoeniceus is demonstrated, nematocyst sensitivity increasing at ambient water temperatures above 23C. Literature is surrmarised and together with the results of this study, provides a basis for future research into Queensland aglaophenids in Keppel Bay and adjacent islands. An extension of this work would be an investigation of the ecological significance of offshore populations of aglaophenids canpared to the nearshore populations. 1 Introduction Aglaophenid hydroids cause human injury, well doc\Jlle(lted in both medical and zoological literature (Bale 1884, Baslow 1969, Bryant 1978, Coleman 1977, F.dmonds 1976, Keegan 1963, Russell 1965, Southcott 1963,1970,1975). Sane or all of the species cited, namely Aglaophenia cupressina Lamarck 1816, ~- mac,gillivrayi Kirchenpauer 1872 (= A. cupressina Laroouroux 1816) Lytocarpus philippinus Kirchenpauer 1872 and h. phoeniceus Busk 1852, may occur along the Central Queensland coast; the presence of allied species will almost certainly be confirmed by an appropriate investigatory programne. No published work has related environmental conditions in the Australian littoral zone and the biology of aglaophenid hydroids. This study aims to: (i) ascertain those species present in Keppel Bay; (ii) obtain information on basic hydrological data in Keppel Bay; (iii) investigate the physico-chemical and biological envirorment in the littoral zone; (iv) study the biology of relevant species; (v) integrate old and new biological data on aglaophenid hydroids with ecological data in Keppel Bay. An extensive literature search including retrospective BIOSIS canputer-based research, showed that references to the morphology and biology of aglaophenid hydroids occur in general works on hydroids, such as those of Hadzi (1963), Hyman (1940), Lenhoff and Loanis (1961), MacGinitie and MacGinitie (1968), Muscatine and Lenl'x>ff (1974), Rees (1966). 2 A total of 365 references were found, dealing either with hydroid morphology, biology, systematics, general cnidarian biology or with the ecology and hydrology of marine, estuarine and intertidal environments. Of these, 197 were generated by the Biosis canputer research programne, a surprisingly limited number of references proving even broadly relevant, as many contained little more than the concept "hydroid". A number of foreign-language papers were cited in the canputer search and translation undertaken of a small number of French and German texts, only those of Gravier (1970) and Meyer(l973} ultimately proving relevant. Fran this extremely wide spectrum of literature, more restrictive criteria provided 28 useful papers dealing with faunistic records, distribution and systematics, 5 with microtechniques, 17 with thecate hydroids in general, 6 with plumularian hydroids in particular, 10 with nematocysts and noxious effects, 24 with general ecology and biology and 13 with hydrology. Australian hydroid literature is mainly taxonanic descriptions of the late nineteenth and early twentieth centuries, in particular Bale's "catalogue of the Australian Hydroid zoophytes" (1884) and his subsequent works of 1888,1913, 1914, 1915, 1919. The very few descriptive works of later date include those of Hodgson (1950), dealing with Tasnanian species, Blackburn (1942) in South Australia and of local relevance, Pennycuick's Faunistic Records fran Queensland, Part V, (1959). Ralph's taxonanic works on New Zealand hydroids (1956, 1957, 1958, 1961a, 1961b, 1961c} and those of Millard (1958, 1962, 1975) on South African species are relevant, in parts, to the Australian 3 hydroid worker as sane degree of biogeographical continuity is acknowledged between the marine hydroid fauna of Australia, New Zealand and South Africa (Blackbum 1942, Fraser 1940, Millard op.cit., Pennycuick op.cit., Ralph op.cit.,) Vervoort (1946,1968) and Van Gemerden-Hoogeveen (1965), although dealing with Caribbean species, have included two relevant cosmopolitan aglaophenids, (L.philippinus and L.