THE BROWN GROUPER
- Friendly Fins
- Nov 18, 2024
- 4 min read
Updated: Mar 7
Why know the brown grouper?
“Simply because I am the Queen of the Mediterranean cliffs, I am hosting you in my home, it is only right to introduce yourself!”
How it differs from other fish:
It can reach one and a half metres in length and weigh up to 70 kg.
It is a fish with a very pronounced head and a wide mouth equipped with large "lips"
The front part of the dorsal fin is equipped with spines that it straightens perpendicular to the body when it feels threatened.
It has two large pectoral fins that it flaps slightly when it relaxes in mid-water.
He has two very large and curious eyes that inspire a certain sense of tranquility!
“But our strong point is the color! You recognize us immediately!”
The coloration of the grouper
It is very varied and colorful: the basic color is brown, more greenish in young specimens, with numerous whitish or light yellow spots on the belly and sides. The dorsal and ventral colors then blend together creating unique shades for each grouper.
Small groupers are also able to change color in a certain way, accentuating the contrast between the light spots and the dark base color.
“This tactic helps us blend in better with the algae and sponges that live on our seabed.”
As the specimens grow they become increasingly darker.
Where the brown grouper lives
The dusky grouper lives sedentary in the Mediterranean Sea, particularly on medium-sloping rocky walls and rocky seabeds, rich in ravines and caves between 10 and 50 m deep. The young specimens instead tend to live and hide inside the Posidonia meadows.
“I am a very calm fish, I love looking for food and resting in warm surface waters, while when I am looking for company to reproduce, I prefer colder waters, above 20 m.”
The brown grouper's den
The brown grouper is a solitary and sedentary species, in fact it has a main den, possibly with two openings to facilitate a possible escape and other temporary shelters.
“We have our favorite abode, just like you!”
The grouper is extremely clever and strategic. Not only does it look for a den with two openings, but it also looks for a narrow one, in which it can fit just right. Why?
"This way we avoid unwanted visits from potential larger predators. Also, by opening our mouths and pointing ourselves with the spines of our dorsal fins at the wall of the shelter, we can get stuck inside, preventing anyone from pulling us out."
What does the brown grouper eat?
The dusky grouper, like any other grouper, is an excellent hunter. It often nests among the rocks, hunting during the day and sucking in with a quick snap of its mouth, a remarkable variety of animals including crustaceans, small fish and cephalopods such as octopuses (its favorites). It tends to hunt in the most superficial meters, up to about fifteen meters deep.
The special life of the brown grouper
It is a very long-lived fish, capable of living up to approximately 50 years.
The male has a harem of about 10 females that he defends from younger suitors.
Sexual maturity occurs around the length of 45 cm.
Protogynous species
“You humans call us that, but to make a long story short, we groupers are all born female and when we reach 80 cm in length we become male! It certainly can't be said that we are not complete fish!”
This sex change was not easy to discover! However, it is now well established that groupers up to about 80 cm are females and after that they are males. This discovery was fundamental. Why? We will soon know…
The courtship
The courtship of the grouper is a great experience to observe: it happens mostly in summer, on full moon nights and at dusk.
The males change color, from a very dark brown, they begin to become increasingly silvery spots on the sides and muzzle, they move very quickly going from greater depths to less and vice versa.
Females, on the other hand, become slightly lighter.
The male has a very difficult task, as he must not only conquer one female but must create his own harem and... Like all females, female groupers are also very demanding!
Once they find a mate, the two swim together, intertwining, with the male's silvery color gleaming in the semi-darkness.
At a certain point they swim quickly towards the surface and at that moment the female will release her eggs into the water and the male will fertilize them.
Once mating is over, the two return to the depths and separate.
“We don’t take care of the little larvae that have just hatched, but we fertilize and produce so many eggs that we have a very good chance of continuing our species!”
Enemies of the brown grouper
The grouper at an early age can easily become prey to larger fish but once adult and imposing it fears no one in its kingdom!
“I love swimming undisturbed between ravines and caves, no one would ever attack me from behind!”
“No one… Except humans…”
The grouper's meat is highly prized, and its considerable size makes it a highly sought-after trophy for underwater and amateur sport fishing.
It has just been said, however, that the largest individuals are males, so if only the largest groupers are fished, it means that only the males are being fished.
This has a catastrophic result for the coastal population of groupers. They are sedentary animals that certainly do not migrate to find a partner. This absence of males makes mating difficult and therefore the survival of the species.
In the last century, groupers have been exposed to a serious risk of extinction precisely because of this fishing aimed at large specimens. Today, however, they are increasing in the Mediterranean Marine Protected Areas, where they cannot be fished.
“When you look closely at us, you will immediately realize that we are shy but also extremely curious fish! We often wonder why you come close to us making strange bubbles and with your camera…
But if you like this so much, we can give you useful tips to get in touch with us without scaring us!”
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