Behaviour

Congratulations. If you read this page, you have reached the extra material that supplements the Red Sea snorkeling guide to the fish of the coral reef. – Through >> this link << and in the footer of each of the pages you will find links to the other pages with extra material that you can also reach through the QR codes in the book.

Fish are doing some activity …
here is always something going on. Many of the fish are constantly moving and they seem busy.
Most often they are busy feeding, and depending on their feeding strategy, their behavior is different: Grazing fish such as the the rabbitfish (spinefoot, see Siganus luridus page 18-19) are busy doing random swimming on top of the reef to feed on the algae that grow with the sun as the energy source. Some fish are very territorial and defend their territory. If you watch the Sohal surgeonfish (page 12) they seem to spend most of their time guarding their area, to make sure they have the algae for themselves.

Many fish are predators and are thus eating other animals either invertebrates (see page 38-39) or other fish. Ambush feeders are sitting still on the reef, e.g. smallscale scorpionfish (Scorpaenopsis oxycephala, page 29) or freckled hawkfish (Paracirrhites forsteri, page 28), waiting to snatch the prey once it come within reach. Mullets are active swimming around in the sandy area swallowing sand (see page 11) . They are filter-feeding – the sand is let out through the gills and small animals are retained in the mouth. They often swim in in small schools in the shallow sandy parts.

You can often find the parrotfish (page 12) biting off corals and you may hear the sound underwater – it is quite loud. Parrotfish feeds on the living part of the coral and if they are not feeding, you may see them swim pooping sand in large quantities. Actually, the parrotfish is to a large degree responsible for the production of white coral sand as one parrotfish can produce up to 400 kg sand per year!
Many fish prefer to stay hidden in the daytime or find protection in the crowd. Fish such as squirrelfish, big eye, and soldierfish (page 32-33) come out late in the day, when the sun is setting.

The Doublebar bream (Acanthopagrus bifasciatus, page 22), many snappers, and yellowfin goatfish prefer staying in a group in the daytime and disperse to feed at night.


 

One of the fish that are active during the day is the Pianofang blenny. It is a small, long, slender but quick fish recognised by the black wavy stripe. It annoys the other fish by biting off some of their scales. It may strike the other fish from behind, if they are not alert. It is also named “hit-and-run blenny” as they quickly swim back to shelter in the reef after an attack.
The Red Sea shrimpgoby is busy on the lookout while the shrimp that it lives with is busy digging out the hole in which they both live.

 

It is always fun to visit a cleaning station. – The bluestreak cleaner wrasse is always busy if other fish wants to get rid of parasites. And if you keep a few meters distance you may see a lot of different species coming for treat. And it is amazing to see a large fish that could easily eat the cleaner wrasse for an afternoon snack turn on the side and open the mouth and let the cleaner wrasse swim in and around the mouth and gills.

Try to focus on a specific fish for a while to see what it is doing. They behavior tells you a lot about the fish, what it eats, if it is mostly active day or night, solitary or prefer groups – live in one spot or cruise the reef, etc.
And remember to notice how it swims – using the tail, the pectorial fins or other…