Carl Reefs 5

Question 1

in which ways is the spacial variation in a reef divided?

Answer 1

• vertical (depth, access to sunlight)
• horizontal position (variation in currents, wave action, salinity, turbidity, temperature)
• interaction of the two spacial scales

Question 2

what is a constant character of the diversity of all reefs, no matter where their location?

Answer 2

distinct communities associated with day and night at all depth levels

Question 3

the diversity within reefs is magnified by what two main aspects?

Answer 3

temporal and spacial variation within areas as well as across areas

Question 4

who is Ronald Thresher

Answer 4

examines patterns in the community composition of coral reef fishes from the Indian, Pacific, and Atlantic oceans
-found patterns of diversity near identical to what has been observed in coral diversity

Question 5

what is the coral triangle?

Answer 5

• comprises of the highest coral diversity in the world
• 76% of the world’s coral species
• In the Indo region

Question 6

Where is the highest coral diversity in the world? by how much?

Answer 6

Bird’s Head Peninsula, Indonesian Papua.

• 95% Coral Triangle, 72% global total
• Raja Ampat in this region has the most.

Question 7

what did Thresher discover in regards to the number of fish families/spp to the location (on a large scale) in the ocean?

Answer 7

As you move eastward in the Pac and Atl oceans the number of fam/spp decline

Question 8

where (on a large scale) is the greatest diversity of coral genera?

Answer 8

greatest in Indo-Pac, lowest in Atl.

Question 9

is there a correlation between where a reef is situated globally and coral/fish spp diversity?

Answer 9

yes. it is a very good predictor.

Question 10

what is a “habitat-based” hypothesis for the pattern of species richness?

Answer 10

• relates to the diversity of habitat, ie: richness of coral diversity, to the diversity of invertebrates and fishes
• the greater the structural complexity, the greater the # of niches, the greater the # of spp in that region

Question 11

what does the ‘success’ of numerous introduced coral fishes to the Hawaiian islands and other localities suggest?

Answer 11

factors in ADDITION to habitat complexity are responsible for the patterns observed

Question 12

what is the impact of lionfish on east coast/carribbean waters?

Answer 12

• predatory reef fish
• reduce native populations
• negative effects of overall reef habitat and health
• eliminate spp that serve important ecological roles (algae-eating fish)
• compete for food

Question 13

what is the ‘extinction’ hypotheses?

Answer 13

-the present pattern of diversity of invertebrates and fishes reflect continental drift and the associated extinction of the original ‘oceania of the tethyan reef fauna’.

Question 14

why is the ‘extinction’ hypotheses not established?

Answer 14

-studies on broader assemblages of organisms have found no clear pattern of extinction across areas that could account for the present patters of diversity.

Question 15

what is the ‘dispersal’ hypotheses?

Answer 15

relate patterns in the present distribution of organisms to the dispersal from the thethyan reef area, which has acted as a centre of speciation and colonization.

Question 16

what are the names of the three hypotheses presented to account for the observed patterns of species richness?

Answer 16

• habitat-based
• extinction
• dispersal

Question 17

what are the two spawning modes predominate in reef-associated fishes?

Answer 17

• Pelagic (independent, floating)

- Desmersal (adhesive, attended by parents, usually)

Question 18

Desmersal spawning spp are divided into what two groups?

Answer 18

• Balistid-type: triggerfish, porcupine fish. tend eggs for a short period. larvae hatch quickly.
• Normal desmersal spawning: incubate and end eggs for a relatively long time. larvae well developed at hatch

Question 19

which types of reef fish have longer larval stages?

Answer 19

-pelagic
-balistid-type
(eggs released into off-shore currents, associated with tides)

Question 20

what is the correlation between proportion of pelagic spawners to the further you move east?

Answer 20

general increase in the proportion of pelagic spawners and general decrease int he proportion of normal demersal spawners on reefs as you moved east from the indo-pac oceans
-proportion of pelagic fishes increases

Question 21

what is the diversity pattern of remote eastern pacific reefs in regard to spawning practices?

Answer 21

even within pelagic-type fishes, those on remote pacific reefs were spp more likely to spend longer at sea before settlement on average than those found in the indo pac.

Question 22

what did Peter Sale discover about the diversity of individual fishes in isolated patch reefs in Aus?

Answer 22

• the numbers fluctuated greatly at times

- the fluctuations were asynchronous

Question 23

the actual community structure of a reef appears to be what?

Answer 23

a highly plastic thing, both spacially and temporally

Question 24

what is unusual about cardinal fishes?

Answer 24

although they are normal demersal-spawning fishes, they are concentrated around home reefs.

• spacial distribution is not random in all cases
• larvae us ELABORATE SENSORY MECHANISMS to orientate themselves and find their way to appropriate habitats

Question 25

coral reefs community structure is not ultimately determined by intense competition on the reefs after settlement, instead is also related to what?

Answer 25

stochastic (variable and unpredictable) settlement patters of larvae.

Question 26

what does Sale’s ‘Lottery hypotheses’ relate to?

Answer 26

• c-reef fishes compete for space
• competition would only affect eh overall numbers, not the overall abundance
• PATTERNS OF CHANGE IN THE COMMUNITY STRUCTURE ARE DRIVEN BY STOCHASTIC RECRUITMENT EVENTS

Question 27

what is the predation disturbance model?

Answer 27

a hypotheses that predation or other disturbance events keep populations below levels at which resources become limiting

• predation is the selective structuring force on reefs
• predators shape the intensity of competition, hence the role of competition in determining community structure

Question 28

how do cleaner fish help reefs?

Answer 28

-increases the number and diversity of ‘transient’ coral spp, those either big enough or man enough to move among reefs.

Question 29

what is the ‘recruitment limitation model’?

Answer 29

that there would never likely be enough larvae to fully utilize the available resources on a reef

Question 30

what are the four recruitment/competition models?

Answer 30

• competition model
• predation disturbance model
• lottery model
• recruitment limitation model