Sympatry in fiddler crabs (genus Uca ) at their hot-spot of diversity in the Wakatobi Marine National Park, Indonesia.

This presentation explains the research I am currently undertaking within the Wakatobi, Indonesia.

Transcript

1. Sympatry in fiddler crabs (genus Uca ) at their hot-spot of diversity in the Wakatobi Marine National Park, Indonesia. L. Michie¹*, S. Cragg¹, R.S.K. Barnes², S. Armbruster ¹ ¹ Institute of Marine Sciences, University of Portsmouth, Ferry Road, PO4 9LY ²Biodiversity Program, Queensland Museum, Brisbane, Australia *laura.michie@port.ac.uk
2. Wakatobi Marine National Park, South East Sulawesi
3. Ambeua mudflat – sympatric site
4. • Intertidal crustaceans of the genus Uca. • Males are characterised by extreme cheliped asymmetry • Active during the low tide, when they come out to feed. What are Fiddler Crabs?
5. Uca jocelynae Uca crassipes Uca tetragonon Uca triangularis Uca demani Uca perplexa
6. Uca mjoebergi Uca dussumieri Uca cryptica Uca coarctata ?
7. Species distribution • Area – 23.5m by 50m • 5 transects perpendicular to the shore line • 2 transects extended up into the mangrove • Belt transects from mangrove edge extended 30m towards shore • 2m² quadrats drawn out • All individuals identified and recorded
8. Species distribution 100 110 120 130 140 150 160 170 180 190 200 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 Height from shore (cm) Distance from low tide line (m) Transect 2 - species distribution and shore height profile U. crassipes U. jocelynae U. perplexa U. mjoebergi U. dussumieri U. tetragonon U. demani U. annulipes U. triangularis Shore profile
9. Species Distribution 100 110 120 130 140 150 160 170 180 190 Shore Height (cm) Distance along transect (m) Uca jocelynae distribution 100 110 120 130 140 150 160 170 180 190 Shore Height (cm) Distance along transect (m) Uca mjoebergi distribution
10. Temporal analysis • Transects and quadrats drawn out • 10 photos taken per quadrat • Photos taken every hour during the low tide period • Photos analysed to identify and record crabs present
11. Territory analysis • Markers made for each species • Each marker noted with either MA (Male Adult), FA (Female Adult), MJ (Male Juvenile) or FJ (Female Juvenile) • Quadrats (10) chosen at random and all occupied burrows marked • Completed quadrats photographed to record makers • Crabs territory sizes determined • Photographs analysed for territory overlaps
12. Sediment composition analysis • Sediment samples collected from T2 and T4 and specific areas of populations • Top 5mm sampled • ~10g of each sample measured and wet sieved (1mm, 500µm, 250µm, 125µm and 63µm) • Sieved content transferred to filter papers • Filter paper dried in oven at 60°C for 48 hours
13. Mouthparts and SEM Setae on the second maxilliped of an Australian Uca perplexa. Spoon shaped setae suggest crabs feed on sandy sediment.
14. Taxonomic classification • Gonopod shape shows interspecific variation amongst males • In absence of molecular phylogeny, gonopod analysis is the primary means of identification • Specimens were chosen from two separate geographical areas for each species • Gonopods were removed and drawn using a camera Lucida Naderloo, et al. a, Uca lactea; b, Uca mjoebergi; c, Uca iranica; d, Uca perplexa a b c d
15. Micro Computed- Tomography
16. Time lapse of Ambeua – 10/08/12
17. Changing Seas and Impacts • Temperatures rising • Ocean acidification • Sea levels rising • Anthropogenic impacts • Biodiversity loss
18. Understanding sympatry • Important when considering high levels of biodiversity • Populations will have to adapt to change • Species may be driven to coexist to survive
19. Any Questions?