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The Evolution and Adaptations of Deep Sea Animals
Matt Brennan
What is the deep ocean?
• Aphotic zone– Depths > 200m
• Lack of food– Falling organic matter
• Very high pressures– Between 20 - 1,000 atmospheres
• Low temperatures– 3-10 degrees Celsius
• Lack of oxygen
“The Deep”
Research Objectives
• Investigate how deep sea Anglerfish (Ceratioidei) and Macropinna microstoma have adapted in order to survive in harsh environments.
• Investigate possible phyogenetic relationships between Anglerfish in the family Ceratioidei
Anglerfish - Lophiiformes
• Lophiiformes• Primitive Lophiiformes
– Shallow water– Bony fish– structure of the first
dorsal-fin spine - bearing a terminal bait or esca
– The teeth in the jaws are numerous, small
• 322 living species– 5 Diverse sub-orders
Anglerfish - Ceratioidei
• Ceratioidei– Sexual dimorphism
• Male dwarf• Loss of illicium• Denticular teeth
• Female - Small eyes• Worldwide distribution– Depth > 300m
• most species-rich vertebrate taxon within the bathypelagic zone
Bioluminescence
• Chemical reaction where energy is released in the form of light
• Bioluminescence in ceratioid– escae w/ bacteria filled
vesicles
• Used to– lure predators– Attract males
http://www.youtube.com/watch?v=UXl8F-eIoiM
Solution to Lack of light?
Sexual Parasitism – Male Ceretioidei
• large well-developed eyes• Loss of illicium• relatively huge nostrils– Sensing female
pheromone
• Denticular teeth– Loss normal teeth after
metamorphosis– jaws for grasping and
holding• Solution to Lack of food?
Male Denticular Teeth• Denticular teeth– Loss of normal teeth
after metamorphosis– Pincer jaws for grasping
and holding– Upper and lower jaws
attacked permanently by tissues
– Obligate parisitism• Solution to lack of food?
Macropinna microstoma - Barreleye • Solutions to light and food:
– barrel-shaped, tubular eyes– Look up towards sun/surface
• Maximize light• Increase contrast perception
– Can see prey against light on surface
• Sensitivity to bioluminescence
– Small mouth• Accurate• Uses eye movement to follow prey
• Transparent shield covering head
– Protection from prey• http://www.youtube.com/watch?v=RM9o4VnfHJU –
watch this
Tubular eyes
• Evolutionary change resulted in changes in locations of muscle insertions– Obliquus muscles pull the
eye forward and down, and the rectus superior and rectus internus returning it to an upright position.
Solution to catching prey?
Conclusions
• Lots of research needs to be done– Relativelely new science!– Environmental factors
are harsh for humans too!
– Lack of live specimen
• A need for the new Generation scientists
Works cited
• Robison, B. and K.R. Reisenbichler (2008). Macropinna microstoma and the paradox of its tubular eyes. Copeia, 4: 780-784.
• http://marinebio.org/Oceans/structures-adaptations.asp• http://www.seasky.org/deep-sea/anglerfish.html• Robison, B.H., K.R. Reisenbichler, J.C. Hunt, and S.H.D. Haddock (2003). Light
production by the arm tips of the deep-sea cephalopod Vampyroteuthis infernalis. Biological Bulletin, 205: 102–109.
• Maddison, D. R. and K.-S. Schulz (eds.) 2007. The Tree of Life Web Project. Internet address: http://tolweb.org