Grouper are a family of fish found in marine environments around the world. They have stout bodies, large mouths, and come in a variety of colors depending on species. While not fast swimmers, some grouper species can grow very large, over a meter in length and 100 kg in weight. Grouper reproduce through both sex change and dedicated sexes depending on species, with larger males typically controlling harems. They are an important part of marine ecosystems, preying on other fish and invertebrates while also serving as prey for larger predators.

1. Grouper
By: Megan Rard
Marine Science “B”

2. Taxonomy
Class: Actinopterygii
Family: Serranidae
Subfamily: Epinephelinae
Genus: Plectropomus

3. Range Map

4. Description
• Stout body
• Large mouth
• Many different kind of colors on scales (due to
vary of species)
• Not fast swimmer
• Can grow large and lengths over a meter
• Weights up to 100 kg but are not uncommon
• Some in large group, considerable due to vary of
species

5. Large mouth
Stout body
Red grouper (different scales)

6. Description
• Rather to swallow prey than biting it off
• Not many teeth on the edges of their jaws but
have a heavy crushing tooth plates inside the
pharynx (part of digestive system and
respiratory system)

7. Size
• Largest: Giant grouper
– up to 2.7 meters (8.9 ft.) in length
– 400 kg (880 lb.) in weight
– Some unconfirmed report said it has grew bigger
up to 10 ft. and 1,320 pounds
• Smallest: Saddletail grouper
– up to 200 cm in length
– at least 68 kg in weight

8. Giant grouper
Saddle tail grouper

9. Reproduction
• Mature female have the ability to change sex after sexual
maturity
• Few species grow about kg per year until they reach 3 kg to
become female
• The largest males often control harems containing three to 15
females
• Often pair spawn which enables large males to competitively
exclude smaller males from reproducing

10. Reproduction
• If a small female grouper were to change sex before it could
control a harem as a male it would decrease if no males are
available
• The largest female that can increase by changing sex will do
• Some groupers are gonochoristic
• Gonochorism is a reproductive strategy with two distinct
sexes, has evolved independently in groupers at least five
times.

11. Reproduction
• Both group spawning and habitat cover increase the likehood
of a smaller male to reproduce in the presence of large males
• Males grouper in environments where competitive exclusion
of smaller males is not possible is correlated with sperm
production and the testicle size
– Gonochoristic groupers have larger testes than protogynous
groupers (10% of body mass compared to 1% of body
mass)

12. Reproduction
• Indicating the evolution of gonochorism
increased male grouper in environments where
large males were unable to competitively
exclude small males from reproducing

13. Groupers like to eat…
parrotfish
wrasses
damselfishes
snappers plankton
microalgae

14. Groupers like to eat…
other small microorganisms
octopuses
crustaceans
crabs lobsters
And their own species!

15. Can human eat a grouper?
• Yes!
• BUT… be aware because variety of parasites
that affect the nostrils, stomach and intestines.
• Some of these parasites include isopods, larval
tapeworms, nematodes, trematodes, and
cestodes.

17. Side effects
• Called Ciguatera Fish Poisoning
• Symptoms:
–DIARRHEA
–ABDOMINAL CRAMPS
–VOMITING

18. Interesting Facts
• Grouper mouths and gills form a powerful
sucking system that sucks their prey in from a
distance
• Also use their mouth to dig into sand to form their
shelters under big rocks, jetting it out through
their gills
• Their gills muscles are so powerful, it is nearly
impossible to pull them out of cave if they feel
threated and extend those muscles to lock
themselves in

19. Interesting Facts
• Nassau grouper can produce a variety of loud
booming sounds, created by vibrating the
swim bladder, in an attempt to intimidate
predators
• Goliath grouper have ability to produce a
distinctly audible rumbling sound generated by
the muscular contraction of the swim bladder

20. Nassau grouper

21. My favorite grouper
Yellowfin grouper