Reproductive and growth variation of the gorgonian Junceella fragilis in southern Taiwan

Transcription

1 Reproductive and growth variation of the gorgonian Junceella fragilis in southern Taiwan Tung-Yung Fan 1, 2, I-Chu Huang 1, 3 and Shinn-Pyng Yeh 3 1 National Museum of Marine Biology and Aquarium, Pingtung, Taiwan 2 Institute of Marine Biodiversity and Evolution, National Dong Hwa University, Pingtung, Taiwan 3 Department of Aquaculture, National Pingtung University of Sciences and Technology, Pingtung, Taiwan

2 Gorgonian corals Gorgonian coral community Stony coral community

3 The role of Kenting, Taiwan in coral reef research Coral biodiversity map Taiwan NMMBA Kenting National Park Healthy and diverse coral reef communities > 250 hard coral species > 50 soft coral species > 50 gorgonian coral species

4 Abundant gorgonian resources in Kenting, Taiwan

5 NMMBA: Center of Excellence for Research, Education, and Conservation of Coral Reefs Public aquarium Coral reef >100 species; 50,000 cultured corals 2 million visitors per year 17 PhDs 30 graduate students per year World-class research facility Husbandry Institute of Marine Biodiversity and Evolution Institute of Marine Biotechnology

6 Life-size coral exhibition and mass coral culture

7 The gorgonian coral Junceella fragilis

8 Comparison of environmental conditions at the four study sites Water turbidity Upwelling Wave & current Xiashuijui High No Weak Wanlitong High No Weak Talauko Low Yes Weak Leidashi Low Yes Strong

9 Monthly sampling Materials & Methods: Reproduction Histological sections Colony Oocyte Spermary Spicule

10 Materials & Methods: Growth Fleshy tissue Axial skeleton

11 Spatial variability of sex ration Sex ratio of populations in Xiashuijui and Wanlitong was 1:1, while in Talauko and Leidashi was significantly female biased. Location Sex Sex ratio ( F:M ) χ 2 P Xiashuijui G 8: >0.05 Wanlitong G 5: >0.05 Talauko G 29: <0.05 Leidashi G 6:0 4 <0.05

12 Spatial variability of development of oocyte and spermary at small spatial scale

13 Spatial variability of reproductive traits at small spatial scale Xiashuijui Wanlitong Junceella fragilis Talauko Leidashi Mean SD n Mean SD n Mean SD n Mean SD n F χ 2 P Fertile female polyps (%) 22 bc a a c Fecundity (oocytes polyp -1 ) 1.2 b a a bc < Oocyte diameter (μm) 282 b bd a bc < Fertile male polyps (%) 23 b b a < Fecundity (sperm sac polyp -1 ) 1.3 c b a < Spermary diameter (μm) 140 b c a c < abcd means with different letters are significantly different at p< 0.05 Fertile female polyps (%) Talauko Wanlitong > Xiashuijui >Leidashi Leidashi Xiashuijui Fertile male polyps (%) Talauko > Wanlitong > Xiashuijui Fecundity (oocytes polyp -1 ) Wanlitong Talauko > Xiashuijui Leidashi Fecundity (sperm sac polyp -1 ) Talauko > Wanlitong > Xiashuijui

14 Most of the reproductive characteristics, including fertile polyps and fecundity for both females and males, diameter of oocyte and spermary, as well as thickness of fleshy tissue of the Talauko population were significantly higher than other populations. This may be benefited from the tidally induced upwelling with higher nutrient occurring at Talauko. Temperature fluctuation 入入入 T e m p e ra tu re ( ) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan

15 Spatial variability of growth traits at small spatial scale For the Leidashi population, the axial skeleton was significantly thicker, but most of the reproductive chacteristics were significantly lower than those of other populations. It suggests that the Leidashi population had higher investment in the growth of axial skeleton and may be an adaptation to the environment with stronger wave. Junceella fragilis Xiashuijui Wanlitong Talauko Leidashi Mean SD n Mean SD n Mean SD n Mean SD n F P Fleshy tissue (cm) 0.2 ab c a b Axial skeleton (cm) 0.12 b b b a < ab means with different letters are significantly different at p< 0.05 Fleshy tissue (cm) Talauko > Leidashi Xiashuijui > Wanlitong Axial skeleton (cm) Leidashi > Talauko Xiashuijui > Wanlitong

16 Welcome to NMMBA, Kenting, Taiwan!