Species Diversity (Sam Cocchia)

tell me about pycnodonts

Early form of bony fish that showed morphological characteristics that may link them to reef fish (now extinct)

where did the initial phase of reef diversification happen?

west tethys sea

what happened in the last 5 mil years?

huge amount of speciation of reef fish

what is hopping hotspots?

marine biodiversity shift from the tethys sea to SE asia and W melanesia

what did the contact between africa and eurasia form?

a land bridge in the Middle East which separated the Indian and Atlantic Oceans

what did the elevation of the isthmus of panama increasing lead to?

separation of east pacific ocean and caribbean

are barriers always physical

no, east pacific barrier

what does the east pacific barrier do?

Divides the Indo- and East Pacific oceans through deep oceans that are 5000 km wide

what leads to differences in species communities?

Large separations of species' pools and natural selection within specific regions

what can reef diversity also be limited by?

local currents, swimming capacity, and larval phase of species

do reef fish have large variation in ages?

yes, 8 weeks-40 years

what to temperate fish tend to show?

indiscriminate growth and continue to grow throughout life

some reef fish show square growth patterns which means what?

grow rapidly until they reach maturity then reduce somatic growth

what is the parental care of damselfish and triggerfish?

stick their eggs to substrate then guard them like nest

what is the parental care of cardinalfish?

mouthbrooders, male fish keep fertilized eggs in their mouth and maintain the larval fish for some time after hatching

what do male seahorses have where the female deposits eggs to be fertilized and protected?

brood pouch

pelagic larval duration

amount of time larvae of a species spend in the plankton before settling

how are reef fish not just passive particles?

they have swimming capabilities that allow them to change their dispersal patterns

what does the sensory abilities of larval phase help them with?

locate reefs and suitable habitats

olfactory abilities

Help seek out appropriate settlements, some species have shown to prefer odors of corals and common leaves of coastal plants

auditory abilites

Reefs are very loud environments with waves crashing, animals clicking, snapping, grunting, and scraping, larvae fish prefer to settle in loud environments than quiet environments

vision abilites

Enables larvae to choose groups of conspecifics or certain habitats they want to settle in

what do the swimming and sensory abilities influence of the larvae fish?

influence where they eventually settle

where do most larvae settle

close to parents

how many coral reef fish species

6000-8000

what is diversity on individual reefs impacted by?

hydrodynamic conditions, reef zones, reef depth

Hydrodynamic conditions

Different species inhabit rougher conditions in outer reef areas compared to sheltered areas such as reef lagoons or flats

Reef Zones

Different assemblages of reef exist, with diversity being highest in reef crest and slopes

Reef Depth

Some reef fish inhabit more broad depth ranges compared to reef fishes that inhabit more specific depths

what does fish coloration play a role in

mate recognition, reproductive potential, and camouflage

what are three uses of coloration

poisonous/venomous, camouflage, and mimicry

what colors to poisonous and venomous reef fish tend to be?

brightly colored

mimicry

When a species resembles a different species by duplicating color, morphology, or body patterns to confuse other species

batesian mimics

harmless mimics that gain protection from evolving colors and body patterns that make them undesirable for predators

aggressive mimics

Attack prey by looking like a species that prey perceive as harmless

abundance

density, number of individuals in each area

biomass

measured by using established lengths- weight relationships that differ amongst species

how can abundance and biomass patterns be measured?

trophic levels

detritivores

organisms that consume detritus

herbivores

organisms that consume plants such as algae or seaweed

planktivores

organisms that feed on planktonic food

coralivores

organism that feeds on coral

Facultative corallivores

Have diets including corals but also other items such as sponges and algae

Obligate corallivores

Feed exclusively on coral (coral mucus and polyps)

Piscivores

fish that feed on other fish

bottom up disturbances

changes in reef fish habitats

biological disturbances

the loss of live coral cover

physical disturbances

3-dimensional disturbances in the structure of coral reefs generally through the loss of live coral cover

top down disturbances

changes in reef fish populations

stony coral tissue loss disease

Highly lethal coral disease that affects Caribbean stony coral. Leading to the decline of reef systems that provide food and shelter for reef fishes