The giant of the grouper family, the Goliath (formerly called Jewish) has brown or yellow mottling with small black spots on the head and fins, a large mouth with jawbones that extend well past its small eyes, and a rounded tail. The skeletal structure of large Goliath grouper cannot adequately support their weight out of the water without some type of damage.
If a large Goliath is brought on-board a vessel or out of the water, it is likely to sustain some form of internal injury and therefore be considered harvested. Goliath grouper populations declined throughout their range during the 1970s and 1980s due to increased fishing pressure from commercial and recreational fishers and divers.
There have been increases in abundance in certain areas (e.g., Tampa Bay, Charlotte Harbor and the Ten A Thousand Islands), and the distribution of Goliath grouper populations has extended into areas of its former range throughout Florida, including the Big Bend and Panhandle regions. Stock assessment were conducted for Goliath grouper in 2004 and 2010, but both were rejected by a review panel for use in federal management.
At their July 2014 meeting in Key Largo, this committee reviewed the most up-to-date scientific information on Goliath grouper and recommended a new stock assessment for this species. The stock assessment indicates abundance in south Florida has greatly increased since the fishery closed in 1990.
However, in the final step of the review process, the assessment was rejected by an independent panel of scientists for use in federal management due to a lack of reliable indicators of abundance outside south Florida. Goliath are also susceptible to large scale mortality events such as cold temperatures and red tide blooms.
When not feeding or spawning, adult Goliath groupers are generally solitary, sedentary and territorial. Before the Goliath grouper reaches full-size it is preyed upon by barracuda, king mackerel and moray eels, as well as sandbar and hammerhead sharks.
Calico crabs make up the majority of their diet, with other invertebrate species and fish filling in the rest. Reproductive maturity first occurs in fish 5 or 6 years of age (about 36 inches in length) due to their slow growth rate.
These groups occur at consistent sites such as wrecks, rock ledges and isolated patch reefs during July, August and September. Studies have shown fish may move up to 62 miles (100 km) from inshore reefs to these spawning sites.
In southwest Florida, presumed courtship behavior has been observed during the full moons in August and September. On the following slides, you'll discover the 31 different groups, or phyla, of invertebrates, ranging from amoeba-like platoons that stick to the sides of fish tanks to marine animals, like octopuses, that can achieve a near-vertebrate level of intelligence.
Some biologists go so far as to claim that these mysterious creatures are protists rather than true animals or flatworms (see the previous slide) that have “devolved” to a primitive state after millions of years of parasitism. These simple worms possess ganglia (clusters of nerve cells) rather than true brains, and respire through their skin via osmosis, either in water or damp terrestrial habitats.
You may never have heard of this phylum, but Gastrotricha are an essential link in the undersea food chain, feeding on the organic detritus that would otherwise accumulate on the seafloor. As tiny as they are, conifers are equipped with even tinier brains, a marked advance over the primitive ganglia characteristic of other microscopic invertebrates.
Chaetognatha are transparent and torpedo shaped, with clearly delineated heads, tails, and trunks, and their mouths are surrounded by dangerous-looking spines, with which they snatch plankton-sized prey out of the water. The larvae of these invertebrates are parasitic, infesting various insects and crustaceans (but thankfully not humans), while the full-grown adults live in fresh water and can be found in streams, puddles, and swimming pools.
The brush head lives and thrives in areas with marine gravel. Wikimedia Commons The invertebrates known as brush heads were only discovered in 1983, and for a good reason: These miniature (no more than one millimeter long) animals make their home in the tiny spaces in between marine gravel, and two species live in the deepest part of the Mediterranean Sea, about two miles beneath the surface. Symbiont typically live on the bodies of cold water lobsters. Real Monstrosities After 400 years of intense study, you may think human naturalists have accounted for every invertebrate phylum.
The half-millimeter-long Symbian lives on the bodies of cold-water lobsters, and it has such a bizarre lifestyle and appearance that it doesn't fit well in any existing invertebrate phylum. Although they are superficially very similar to Bryozoa (see next slide), Entoprocta have slightly different lifestyles, feeding habits, and internal anatomies.
No, they do not: The sex organs of males and females, such as they are, are merely tiny outgrowths of their protonephridia, the invertebrate equivalents of mammalian kidneys. When threatened, these smallish marine invertebrates contract their bodies into the shape of a peanut; otherwise, they eat by protruding one or two dozen cilia ted tentacles from their mouths, which filter organic matter from seawater.
Aside from their numerous paired legs, these invertebrates are characterized by their small eyes, their prominent antennae, and their disconcerting habit of squirting mucus at their prey. Weirdly enough, a few velvet worm species give birth to live young: The larvae develop inside the female, nourished by a placenta-like structure, and have a gestation period as long as 15 months (about the same as that of a black rhinoceros).
A brightly colored Sally light foot crab is one example of an arthropod. Getty Images By far the largest phylum of invertebrates, accounting for as many as five million species the world over, arthropods include insects, spiders, crustaceans (such as lobsters, crabs, and shrimp), millipedes and centipedes, and many other creepy, crawly creatures common to marine and terrestrial habitats. As a group, arthropods are characterized by their hard external skeletons (which need to be molted at some point during their life cycles), segmented body plans, and paired appendages (including tentacles, claws, and legs).
A gold-mouthed sea squirt is one example of a truncate. Wikimedia Commons Somewhat confusingly, the animal phylum Chordata has three subphyla, once embracing all the vertebrates (fish, birds, mammals, etc.) Lance lets, or Cephalochordata, are fish like animals equipped with hollow nerve cords (but no backbones) running the lengths of their bodies, while truncates, also known as Urochordata, are marine filter-feeders vaguely reminiscent of sponges but much more complicated anatomically.
Although some populations are below target levels, U.S. wild-caught red grouper is still a smart seafood choice because it is sustainably managed and responsibly harvested under U.S. regulations. Fishing gear used to catch red grouper rarely contacts the ocean bottom and has minimal impacts on habitat.
They engulf prey whole by opening their large mouths, dilating their gill covers, rapidly drawing in a current of water, and inhaling the food. Large sharks and carnivorous marine mammals prey on adult red grouper.
Red grouper are found in the western Atlantic Ocean from Massachusetts through the Gulf of Mexico and south to Brazil. Annual catch limits are used for red grouper in the commercial and recreational fisheries.
These fisheries are closed when their annual catch limit is projected to be met. Both the commercial and recreational fisheries have size limits to reduce harvest of immature red grouper.