Category America south – Atlantic Coast – sub tropical ecoregion

Lutjanus spp.

The snappers are a large and diverse group of robustbodied, carnivorous fishes. Most species possess relatively large mouths with stout canine teeth and bodies covered with relatively large, coarse scales. They are frequently brightly coloured. They are demersal (spending most time swimming close to the sea bed) in some cases down to 450m and are found in the tropical and sub topical waters of the Atlantic, Indian and Pacific Oceans. There are over one hundred individual species globally, but within the Pacific Coast Sub-tropical eco region there are only a limited number of species that you are likely to see at diving depth, and these will tend to be in the warmer waters of the region.

Echinometra lucunter

Sea urchins are often used as indicator organisms in public aquariums to determine whether the system is functioning properly. These organisms are extremely sensitive to water conditions and are first to show signs of stress, seen when their spines are laid down or are shed.

Warning! Some sea urchins are covered with sharp venom-filled spines that can easily penetrate and break off into the skin – even through a wetsuit. The DAN (Divers Alert Network) website contains useful information on how to handle the unfortunate effects of accidental brushes with these and other poisonous marine organisms.

Check out www.diversalertnetwork.org for any information that you need.

Sea urchins (echinoderms) are a group of marine invertebrates that can be found in almost every...

Especially Spiny Lobster Palinurus argus

The Palinurus genus (frequently transcribed as Panulirus) is represented by numerous species in all of the world’s tropical and sub-tropical seas as well as more temperate waters. It is a predatory, nocturnal animal with a vividly decorated coat.

They are often numerous locally; they linger in crevices (with their long antennae sticking out) during the day and hunt small benthic organisms at night, but they also feed on organic detritus whenever they happen across it. Lobsters have recently suffered a dramatic demographic decline; intensive fishing has annihilated entire populations, especially where tourism abounds.

Please record all sightings of lobsters, identifying individual species where possible.

However, we would particularly appr...

Serranidae (Epinephelus marginatus E. itajara and Mycteroperca acutirostris)

When people talk about coral reefs, fishermen tend to shrug their shoulders and complain about snagged lines and torn nets. But when you talk about groupers, they suddenly sit up and pay attention. Groupers are among the economically most important fishes of the coral reef, because of their popularity as food.

Yet without the coral reef there would probably be no groupers. For this reason, groupers are an extremely important indicator species and your record of their existence or non-existence during your dive tells us a lot. Like all indicators, it is valuable if you can record the particular species you sight. However, recording the total number of groupers is just as important. The species that we
would...

Identifying sharks in the wild is a great challenge! While scientists can spend weeks examining every detail of a species, divers may encounter a shark for only a few seconds or minutes. Many species look alike and one individual may not be identical to the next. There are, however, relatively few species in any one specific dive site and with some preparation and a little practice it is possible for all of us to recognise the more common and distinctive species. The key to successful shark identification underwater is a process of elimination, based on a mental checklist of the main features to look for in every animal encountered. One feature alone is rarely enough for a positive identification, so gather as much information as you can before drawing firm conclusions.

earthdive wants you...