the evolution and adaptations of deep sea animals matt brennan

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