Beast Of The Day (Midterm 3)

Question 1

(1) Great Frigatebird (feeding)

Answer 1

-lightly built, large
-spends majority of time on the wing foraging, can sleep in flight (12 seconds intervals)
-travel >3000km in 10 days, <80km from breeding sites when feeding chicks
-flying fish=common food, pick fish from water surface
-use schooling fish to cue foraging (increases foraging success)
-hunt chicks of other seabirds
-never lands on water, unlike most sea birds
-long wings (wouldn’t be able to take off once they land on the water)
-no oily feathers (can’t prevent from getting water logged)

Question 2

(1) Frigatebird (reproduction)

Answer 2

-30-40 yrs lifespan
-start breeding at 8+ yrs old
-breed in remote oceanic islands - coral atolls
-group nesting (10-30 individuals)
-male gathers sticks and builds elaborate nest, with other males
-males sit on nest and display to attract females
-philopatry: return to the same nesting area year after year
-single egg (6-7% of female’s body weight) (40-55 day incubation)
-chick fed 5-6 months before fledgling- regurgitated food
-parental care up to 400 days after fledgling
-young birds stick play
-breeding alternates years -> labor intensive

Question 3

(1) Frigatebird (threats)

Answer 3

-other Frigatebird species are vulnerable to- many seabirds are endangered
-fishing debris
-habitat loss-introduced goats
-feral cats
-invasive rats

Question 4

(2)Lionfish

Answer 4

-ridge of spines along dorsal side
-venom producing tissue runs down side of spines
-hypodermic needles delivers venom to whatever is punctured
-live up to 15 yrs-> reproduce after <1 yr
-females produce mucus-filled egg clusters
-15,000 eggs per cluster
-can spawn every 3-4 days->2 million eggs/yr
-larvae have 30 day PLD->larvae can disperse far

Question 5

(2) Lionfish distribution

Answer 5

In Native range:
-inhabit reefs in low densities
-shallow typically <30m -80 depth limit

In the Atlantic (invasive):
-coral reefs, seagrass beds, mangroves, estuaries, artificial structures
-extremely high densities
-shallow (.5m) to deep (>300m)
-saline (open ocean) to brackish (nearly fresh water)
-can survive in 7ppt for >1month

Question 6

(2) timeline of Lionfish invasion

Answer 6

Vector: Aquarian trade via humans
-introduction: Florida and Biscayne bay
-naturalized: numerous sightings reported
-invasive: seen throughout eastern seaboard of US, gulf, and Caribbean

Question 7

(2) Lionfish feeding strategy

Answer 7

-piscivores
-suction feeders
-gape-limited
-blows jests of water at prey (confuse/disorient, increases change of head-first capture)
-aggregations of Lionfish herd prey into area to eat
-voracious predators (eat a lot resulting in fatty liver disease, stomach expands 30x normal volume, can go months without eating)

Question 8

(2) what makes Lionfish so successful?

Answer 8

-rapid growth
-early maturation
-long PLD
-enemy release (predators in introduced range don’t recognize Lionfish as possible prey)
-venomous spine
-naive prey

Question 9

(2) Lionfish enemy release and naive prey

Answer 9

Enemy release: predators don’t recognize Lionfish as possible prey
-differ behaviorally and morphologically from native fish
-defensive spines may deter predators (lack of adaptation to tolerate venom and knowledge on how to handle prey item)
-also includes competitors, diseases, parasites

Naive prey: prey doesn’t recognize Lionfish as potential predator
-Lionfish presence resulted in lower recruitment by 79%
-suppresses natural reef fish population by eating their food

Question 10

(2) impact of Lionfish

Answer 10

-consume native ecologically important spp, esp juveniles (possible trophic effects)
-compete with other piscivores for limiting resources (impacting recreational and subsistence fisheries)

Question 11

(2) what is being done to control the Lionfish population?

Answer 11

-recreational fishing and Lionfish derbies
-promote as a food fish
-develop commercial fishery
-limited evidence for natural predator control
-robots

Question 12

(3) Manta Ray natural history

Answer 12

-Portuguese/Spanish for cloak or blanket
-pelagic
-solitary to groups of 50 or more
-can be migratory
-dives up to 1000m to mesophotic reefs
-adults up to 7m wingspan
-1300kg/3000lbs
-50+yrs lifespan
-highest brain:body mass ratio of all fishes (very intelligent)
-likes to breach to wash off parasites by shocking them by slamming into the water

Question 13

(3) Manta Ray reproduction

Answer 13

-Ovoviviparous->devel in egg case
-gestation 12-13 months (litter of 1 or 2 young)
~24 months btwn gestations
-not gentle mating: males bite onto females while mating, leaving scars

Question 14

(3) Manta Ray habitat and feeding

Answer 14

-open ocean to shallow inshore reefs
-filter feeders: shrimp, krill, plankton (13% of body weight daily)
-uses cephalic fins to funnel water/food into month
-somersault thru rich patches of plankton
-aggregate around schools of plankton

Question 15

(3) Manta ray ecology and identification and humans

Answer 15

-remoras: hitchhikers that pick off food on manta rays
-predators: bull, tiger, hammerhead

-pattern of spots on ventral side->use as a finger print (“mantaprint”)

-IUCN->vulnerable spp
-commercial fishery: gill plates used in traditional Chinese medicine (vulnerable to over fishing)
-favorite “ride” of snorkelers and scuba divers

Question 16

(4) Green Turtle

Answer 16

-called green bc of the color of their flesh and fat due to their diet being mainly of seagrass
-migrate up to 2500 btwn feeding and breeding sites
-hatching turtles spend time in open ocean move more inshore as adults
-lives 50+yrs
-mature at 10-24 yrs (mate at sea, females can retain sperm to nest a couple times a yr)
-nest on same beaches that they were born
-lay 100-200 eggs gestation, 40-72 days
-temp dependent sex development (<28 degrees C males, >29.5 females)->climate change risk, less males to breed with

Question 17

(4) Green Turtle feeding

Answer 17

-adults: mostly seaweeds, seagrass
-juveniles: crabs, sponges, snails, jellys
-important grazer in seagrass beds->possibly on coral reeds
-predators: large sharks, humans

Question 18

(4) Green turtle exploitation and conservation challenges

Answer 18

-fished for 100s of yrs, over harvesting
-before Europeans: pop ~30-40 million
-current: 100,000ish
-protected endangered spp

Conservation challenges:
-protecting nest sites from destruction
-egg poaching and nest predation (foxes, raccoons, domestic animals)
-trash and marine debris
-turtle tumors (fibropapillomatosis): benign, but can affect vision, feeding, swimming escape from predators

Question 19

(5) Goliath Grouper natural history

Answer 19

-live to 35+yrs at least (indeterminate growth)
-protogynous sequential hermaphrodite (female 1st)
-spawn in aggregations, gather together for mating
-pelagic larvae: move with currents over long distances
-juvenile Goliath settle in mangroves, seagrass beds, oyster reefs (5-6 yrs)-> move deeper as adults (ontogenetic changes)

Question 20

(5) Goliath grouper habitat, feeding, and exploitation

Answer 20

-coral reefs and hard bottoms, top predators
-eats fish, crustaceans (lobster), octopus, young sea turtles, sharks
-feeds by sucking in prey

-heavily fished from 1800s forward->led to drastic population decline in 1970s-80s
-“critically endangered”
-protected in US since 1990
-present day: substantial recovery in population (fishers want protection removed)