Too Cool For School

1
Too Cool For School
Borophryne apogon
Pachystomias microdon
Bertella idiomorpha
Aristostomias sp.
Photocorynus spiniceps
2
Special Habitats

• Extreme conditions
• Require unique adaptations
• Deep sea
• Caves
• Polar
• Deserts and Arid Environments

3
Cave Fishes

• What are the extreme conditions of the cave
  environment?
• What are the adaptations of the fishes?

Typhliasina pearsi
Typhlichthys subterraneus
4
Response to Darkness

• Pigmentation lost
• Eyes lost
• correlates with age of colonization
• Other senses increase
• Brain and inner ear change why?
• Loss of scalation

Astyanax mexicana
Amblyopsis rosae
5
Response to Low Productivity

• Metabolic rate lowered
• more efficient swimming
• more efficient food storage
• Life history
• fewer eggs with more yolk
• longer maturation
• longer life span
• Food regulates population density

Cryptotora thamicola
Trogloglanis pattersoni
6
Grotto Sculpin

• Five caves in Perry Co., MO
• Compared to banded sculpin
• reduced pigmentation
• smaller eyes
• increased sensory pore
• altered brain morphology
• reduced metabolism
• Consistent with transition to troglobitic
  lifestyle

grotto sculpin
Cottus carolinae
7
Polar Regions
ca. 110 species low/no endemism
ca. 313 species high endemism (88)
8
Antarctic Convergence

• Demarcates the Southern Ocean
• Cold water sinks below warmer water
• How does this relate to deep-sea fishes?
• Distinct temp, salinity, water chemistry
• Region of upwelling
• May explain endemism

9
Freeze Prevention
Pagothenia borchgrevinki

• Seawater freezing point is -1.9C
• Live gt 30m deep
• Antifreeze glycoproteins
• lowers blood freezing point to -2.2C
• kidneys lack glomeruli
• why?

Dissostichus mawsoni
10
Freeze Prevention

• No hemoglobin
• What adaptations are necessary to offset lack of
  hemoglobin?
• Achieve neutral buoyancy
• cartilaginous skeleton
• reduced ossification
• lipid deposts

Pagetopsis sp.
Pleuragramma antarcticum