Propagation and Nutrition of the Soft Coral Sinularia sp. By Luís Filipe Das Neves Cunha University of W ales, Bangor School of Ocean Sciences Menai Bridge, Anglesey This Thesis is submitted in partial fulfilment for the degree of Master of Science in Shellfish Biology, Fisheries and Culture to the University of W ales October 2006 1 DECLARATION & STATEM ENTS This work has not previously been accepted in substance for any degree and is not being concurrently submitted for any degree. This dissertation is being submitted in partial fulfilment of the requirement of M.Sc Shellfish Biology, Fisheries & Culture This dissertation is the result of my own independent work / investigation, except where otherwise stated. Other sources are acknowledged by footnotes giving explicit references. A bibliography is appended. I hereby give consent for my dissertation, if accepted, to be made available for photocopying and for inter-library loan, and the title and summary to be made available to outside organisations. Signed................................................................................................................................. ..................................................... … … … … … … … … … … … … ..… … … … .. (candidate) Date..................................................................................................................................... ....................................................................... … … … … … … … … … … … … … … … … … . 2 Índex Abstract.......................................................................................... 5 1. Underlying rationale .................................................................. 6 1.1 Introduction............................................................................................................ 6 1.2.1. Ornamental Marine Species Market................................................................... 7 1.2.2 Exploitation, Environmental Impact and Sustainability...................................... 8 1.3. Soft Corals........................................................................................................... 11 1.3.2 Morphology and Anatomy................................................................................ 11 1.3.3 Ecology and life history..................................................................................... 13 1.3.4 Life history........................................................................................................ 14 1.3.5 Sinularia sp. ....................................................................................................... 14 1.4 Culture Requirements........................................................................................... 15 1.4.1 W ater Quality.................................................................................................... 16 1.4.2 Feeding and Nutrition........................................................................................ 17 1.4.3 Artificial Propagation........................................................................................ 20 1.5 Aims of the present study...................................................... 21 2. Methodologies.......................................................................... 22 2.1 General Methodologies......................................................................................... 22 2.1.1 Transportation................................................................................................ 22 2.1.2 Acclimation................................................................................................... 22 2.1.3 Parent Colony maintenance and W ater Quality............................................ 22 2.1.4 Artemia Culture ............................................................................................. 23 2.1.5 Morphometric Measurements........................................................................ 24 2.2 Experiments.......................................................................................................... 24 2.2.1 Damage recovery and growth under standard conditions............................. 24 2.2.2 The Effect of feeding against starvation in two culture methods.................. 28 2.2.3 Description of Daily Feeding Pattern and Ingestion Rates............................ 29 2.2.4 The Effect Zooplankton Concentration on Feeding Rate.............................. 29 3. Results...................................................................................... 30 3.1 Description of morphometric relationships...................................................... 30 3.2 Damage recovery and growth under standard conditions................................ 32 3.3 The Effect of feeding against starvation in two culture methods..................... 39 3.4 Description of Daily Feeding Pattern............................................................... 45 3.4.1 Ingestion Rates.................................................................................................. 45 3.4.4 Daily pattern of the ingestion rate ..................................................................... 47 3.5 The Effect Upon Feeding of Zooplankton Concentration.................................... 48 3.5.1 Ingestion Rates.................................................................................................. 48 4. Discussion................................................................................ 49 4.1 Description of morphometric relationships...................................................... 49 4.2 Damage recovery and growth under standard conditions................................ 49 4.3 The Effect of feeding........................................................................................ 53 4.4 Description of Daily Feeding Pattern............................................................... 55 3 4.5 The Effect of Zooplankton Concentration........................................................ 56 5. Conclusion................................................................................ 56 6. Acknowledgements.................................................................. 59 Reference list................................................................................ 60 4 Abstract Due to their biology, soft corals are known to be hardy, fast-growing and easily propagated species under aquarium conditions, however there is a lack of scientific studies on their culture, and very few species are artificially cultured. Colonies of the soft coral Sinularia sp. were propagated under standard conditions under two different culture methods. Colonies recovered significantly faster in suspended culture (p<0.05); colonies cultured on the bottom never achieved the same healing development for the same experimental time. Colonies cultured in suspension showed a significant higher tissue energy content than those cultured on the bottom (P<0.05). Therefore the culture in suspension showed some advantages against culturing on the bottom. Colonies were also cultured under fed and unfed regimes under both culture methods but there was no significant difference in growth between treatments. This suggests that Sinularia sp., despite being mixotrophic, can strongly rely in nutrition from the symbiotic relation with zooxanthellae. The feeding daily pattern was observed in Sinularia sp. colonies using Artemia nauplii as live food (5 ml-1). A mean ingestion rate of 6.84 nauplii polyp- 1 d-1 was found for Sinularia. sp. colonies. This is higher than reported values in other soft coral species in the natural environment but probably is due to the higher feeding concentrations used in captivity. Colonies contract during night and therefore stop feeding reducing the feeding time and calculations were made based on 12h feeding period per day). Three different feeding concentrations were tested (2, 5 and 10 nauplii per.ml-1) but there were no significant differences in the ingestion rates and therefore provision of live food at 2 ml -1 is considered sufficient. Luís Cunha Praca Joao XXIII n.560, 6Dto, 4490-440 Povoa De Varzim, Portugal Email: luis.cunha@ linus.uac.pt 5 1. Underlying rationale 1.1 Introduction In contrast to freshwater ornamentals, most marine ornamentals come directly from natural systems, principally from coral reefs (Hoff, 2001; Lin et al., 2002; Tlusty, 2002)). The exploitation pressure is more pronounced in Indo-Pacific seas, where countries such as Philippines and Indonesia are the highest regions of exploitation (W abnitz et al., 2003). This exploitation can be defined as the removal of marine organisms of major interest to the marine aquarium market. W ith the removal of —key species“ and the use of destructive techniques such as explosives and chemicals, the environmental impact is significant, principally because such techniques are often selective, they affect not only the target species but also other organisms within range (Moore and Best, 2001; W ood, 2001; W abnitz et al., 2003). Aquaculture of marine ornamentals can be a solution to release some of the present exploitation pressure on natural systems (Lubbock and Polunin, 1975; Rubec, 1988). In addition the aquaculture of ornamentals can only be achieved trhough combination of science and technology in order to develop current techniques for ornamental aquaculture (W abnitz et al., 2003). In fact, despite the exponential growth of marine ornamental market very few species are presently cultured (Delbeek, 1987;