Infolific » Coral Reef Life

Marine Invertebrates: Some Can See and Some Can't

Travis Burke — Sat, 05 Jan 2013 22:23:22 +0000

The brilliant colors of coral reef fish are matched only by those of the invertebrates that share their habitat. From soft corals to harlequin shrimps and nudibranchs, vivid colors are the rule rather than the exception. As even the colors are not simple embellishments, but a crucial part of the [...]

Marine Fish Larva Development

Travis Burke — Mon, 31 Dec 2012 20:57:14 +0000

When the embryo hatches from its egg and begins the next stage of its life as a larval fish, the pace of its development remains rapid. The odds of it surviving past the larval stage are still tiny, but to have any chance at all it needs to grow -- [...]

Reef Fish Diets

Travis Burke — Fri, 14 Dec 2012 02:47:22 +0000

Over tens of thousands of years, fish have evolved to be expert foragers, feeding on a huge range of different food sources, both animal and vegetable. Some have become specialists on a certain kind of food, others are opportunists, feeding on whatever they can. One thing all species have in [...]

Sunlight - The Start of the Food Web

Travis Burke — Mon, 26 Nov 2012 21:40:17 +0000

The shallow sunlit waters provide the perfect conditions for plant growth. The algae provide a rich and solid foundation to the food web on the reef, supporting a wide range of herbivores. But one of the most important groups of organisms on the reef are the specialized algae known as [...]

Learning From Others

Travis Burke — Wed, 21 Nov 2012 20:01:36 +0000

For most of their lives, coral reef fishes live in close contact with hundreds or even thousands of other reef dwellers. There are disadvantages to this in terms of shortages of space for territories and high levels of competition for food. But there is some compensation for the fish in [...]

Fish Learning

Travis Burke — Thu, 15 Nov 2012 05:49:59 +0000

To survive in the competitive environment of the coral reef, fish need to be adaptable. Those with the ability and the intelligence to learn and to adapt their behavioral strategies are the most likely to come out on top. The image that many people conjure up when the question of [...]

Recognizing Other Fish

Travis Burke — Sun, 04 Nov 2012 14:00:32 +0000

The ability to recognize others is vital to fish. They have to know whether the individuals they encounter are predators, competitors, or members of their own species that might potentially be a breeding partner. This recognition can be performed in a number of different ways, but the patterns and colors [...]

Advertising Toxicity to Defend Against Predators

Travis Burke — Sat, 06 Oct 2012 01:18:00 +0000

Although chemical defenses can provide excellent protection for many reef organisms, there is always a danger that an inquisitive predator might launch an attack before realizing its mistake. Although this may have dire consequences for the attacker, the prey animal may also suffer serious injury. Therefore, it pays for animals [...]

Navigating the Reef

Travis Burke — Sat, 29 Sep 2012 16:49:06 +0000

Although a reef may look to us like a huge continuous environment, the reality for fish is much more complex. Their habitat is a patchwork of hiding places, feeding sites, and fiercely defended territories. Being able to orientate within the environment is therefore a crucial skill for fishes. It is [...]

The Coral Reef During the Day

Travis Burke — Thu, 27 Sep 2012 21:19:21 +0000

The coral reef during the day is a dazzling collage of colors and activity. Huge numbers of fish and invertebrates bustle around the reef in a way reminiscent of a human city. In the tropics, day and night are of similar length, so before retiring to the relative safety of [...]

Finding Food in Seagrass Beds

Travis Burke — Mon, 17 Sep 2012 08:19:24 +0000

The sandy plains and seagrass beds that exist in coral lagoons and in the spaces between large coral heads are home to a variety of invertebrates, including mollusks, worms, and shrimps. Some of these animals seek shelter by hiding beneath the sand at certain times throughout the day, away from [...]

Fish Fights: Weighing Up the Opposition

Travis Burke — Wed, 12 Sep 2012 04:57:59 +0000

When rival fish size each other up from afar, the most common outcome is that one of them will recognize the other's superiority and keep its distance, or be chased off without putting up any resistance. But when fish are fairly closely matched in terms of their size and motivation, [...]

How Fish Produce and Detect Sound

Travis Burke — Sun, 02 Sep 2012 23:54:15 +0000

It is ironic that one of the early heroes of coral reef research -- Jacques Cousteau -- chose to call his most famous book, The Silent World. In fact, it is far from silent; these waters are a constant lively hubbub of noise. Recent research has shown that fish communicate [...]

Fish Intelligence

Travis Burke — Fri, 17 Aug 2012 18:43:08 +0000

Asking how intelligent fish are is a relatively new question. It is new in the sense that until fairly recently, the general consensus was that fish had no intelligence and simply reacted to various stimuli like mindless little robots. Gradually, more evidence has accumulated from a range of different studies [...]

Using Behavior for Communication

Travis Burke — Thu, 16 Aug 2012 11:53:17 +0000

Body language -- communicating with others through behavior -- is a vital part of the behavior repertoire of all visual animals and fish are no exception. A wide variety of signals can be transmitted through body language; some are relatively subtle, but others are very deliberate and obvious. When it's [...]

Poisonous Reef Fishes

Travis Burke — Wed, 15 Aug 2012 17:17:47 +0000

The Stonefish is Poisonous Enough to Kill a Person Reef fishes face the same predation pressures as invertebrates, so it is perhaps not surprising that some of them, too, defend themselves with toxins. However, fish have fewer methods of deploying their poisons. In most cases, they inflict them using their [...]

Coral Reef Ecology

Travis Burke — Fri, 10 Aug 2012 19:56:26 +0000

Coral reefs are home to an incredibly diverse range of organisms, in many cases living at densities that far exceed those found in other aquatic habitats. This is despite the fact that, in most cases, corals live in waters with low levels of nutrients. The total number of fish species [...]

Clownfish and Sea Anemone Behavior

Travis Burke — Fri, 10 Aug 2012 13:51:14 +0000

Probably the most famous example of a symbiotic ("living together") relationship on the coral reef -- if not in the entire animal kingdom -- is the remarkable relationship between clownfish and anemones. How important is this relationship to the partner organisms? It seems that both organisms benefit considerably from the [...]

Invertebrate Feeding Tactics

Travis Burke — Mon, 06 Aug 2012 23:02:49 +0000

It is not only fish that prey on reef invertebrates, nor do all these invertebrates live a life of grazing and filter feeding; there are some fearsome predators among the invertebrates. These hunters have adopted some innovative strategies to get past the sometimes quite considerable defenses of their fellow inverts, [...]

Adult Reef Fish

Travis Burke — Mon, 16 Jul 2012 22:59:35 +0000

The final stage in a fish's life cycle is adulthood. To reach this point, each individual fish must have overcome virtually insurmountable odds with a combination of good luck and good genes. They needed good luck in the earliest part of their existence as eggs and larvae, and good genes [...]

Rhythms of Marine Life

Travis Burke — Tue, 03 Jul 2012 15:59:36 +0000

Fish have three main aims over the course of their lives: to eat, to avoid being eaten, and to reproduce. The way they approach these essential functions varies from species to species, but in the end, it is governed by rhythms. Rhythms might be the short-term rhythm of the Earth [...]

Juvenile Reef Fish

Travis Burke — Fri, 15 Jun 2012 22:37:32 +0000

Less than 1% of the fish that started their journey through life inside the egg survive to settle on a coral reef as a juvenile. These larvae come inshore to the reef, guided by its smells and sounds, often borne on incoming tides and under cover of darkness. Yet even [...]

Cleaner Wrasses

Travis Burke — Tue, 01 May 2012 07:30:38 +0000

Co-operation can sometimes go beyond simple commensalisms and take the form of a real partnership -- a mutualism. One dramatic example is the way that some species of fish and shrimps clean parasites from the skin of larger fish. The high densities of fish found on coral reefs gives rise [...]

Chameleons of the Sea

Travis Burke — Wed, 29 Feb 2012 01:28:20 +0000

Small animals on the reef are in constant danger of ending up as a snack for the ever-hungry predators patrolling the area.This fact of life has driven the evolution of some remarkable adaptations, not least those used by reef animals to blend into their background. For camouflage to be most [...]

Fish Fights: The Lead-Up

Travis Burke — Sun, 26 Feb 2012 12:32:38 +0000

The aggressive nature of many tropical marine fish, particularly their intolerance for their own or similar species, can present a real problem for fishkeepers. Like all animals, fish must compete to acquire resources such as food, territories, or mates. On the coral reef, food, hiding places, territories and mates are [...]

Defending Against Predators

Travis Burke — Sat, 18 Feb 2012 11:02:54 +0000

The coral reef is a dangerous place for all its inhabitants; most animals live in close proximity to a host of dangers and different kinds of predators. Their survival depends on their defenses and their ability to break the predation cycle. For reef fish, self-preservation tactics range from keeping alert [...]

Filter Feeders and Anemones

Travis Burke — Wed, 18 Jan 2012 07:25:03 +0000

By far the majority of individual marine invertebrates on the coral reef feed on microscopic prey borne on the ocean currents, sifting it from the water with a variety of net- and mesh-like body parts. These filter-feeding animals are usually sessile, or at the least slow moving, so they rely [...]

Living on the Reef

Travis Burke — Mon, 12 Dec 2011 05:09:45 +0000

Fish are one of the most successful groups of animals on the planet. There are over 20,000 species of fish, occupying every imaginable habitat. In each case, evolution has shaped both their appearance and their senses over countless generations and millions of years, resulting in the most effective adaptations to [...]

Fish Communicating Through Smell

Travis Burke — Sat, 26 Nov 2011 20:00:32 +0000

Although vision is arguably the most important sense for most inhabitants of the coral reef, their sense of smell also has a key role. Odors may be detected a long distance from their source -- beyond the range of an animal's vision -- and can help, say, a predator locate [...]

Seasonal Changes on Coral Reefs

Travis Burke — Fri, 25 Nov 2011 06:48:19 +0000

At the equator there is very little variation in day length or temperature over the course of the year. As a result, the animals that live on coral reefs at very low latitudes show few regular annual patterns in their growth or behavior. But with each mile traveled north or [...]

Coral Reefs at Dawn and Dusk

Travis Burke — Sun, 20 Nov 2011 22:10:33 +0000

Dawn and dusk are incredibly active times on coral reefs. Together, these twilight, or crepuscular, periods take up only about an hour of each day, which amounts to only about 4% of the 24-hour cycle, but they are extremely important to all reef life. This is a time of transition [...]

Crazy Facts About Marine Fish

Travis Burke — Wed, 10 Aug 2011 11:11:55 +0000

I like to read about marine fish. I also enjoying watching shows like Dicovery Channel's The Blue Planet series. That TV series in particular provided an amazing looking into the world of marine fish. Each book and show seems to have a few interesting tidbits of trivia that I've collected [...]

Invertebrate Use of Smell

Travis Burke — Tue, 19 Jul 2011 10:30:20 +0000

Many reef Invertebrates, especially those that lack a good sense of vision, are acutely sensitive to telltale chemicals in the water. Sometimes even the faintest trace, perhaps consisting of just a few molecules of a key chemical, can trigger amazing behavioral responses. Some chemical odors, such as those that carry [...]

Evading Reef Predators When Chased

Travis Burke — Wed, 13 Jul 2011 10:24:40 +0000

When a predator launches an attack, it is time for prey animals to get out of the way with all speed. Of course, anywhere will do to start off with, so long as it is away from danger. However, if the prey animal is cut off from safety, then its [...]

Development of a Fish Egg

Travis Burke — Sun, 10 Jul 2011 10:14:34 +0000

Fish begin life inside an egg. As we have seen, for many coral reef species the exact moment of fertilization occurs in the water column amid a swarm of predators -- not the easiest start in life! From this point on the pace of development is relentless; eggs are an [...]

Fish that Eat the Coral Reef

Travis Burke — Fri, 01 Jul 2011 08:30:27 +0000

Coral reefs are by far the largest animal-built structures on Earth. The Great Barrier Reef stretches for nearly 1,500 miles (2,400 km) and is even visible from space. Nevertheless, most of the coral reef is dead, composed of the skeletons of individual polyps. Only the superficial layer of the reef [...]

The Importance of Algae on the Reef

Travis Burke — Tue, 28 Jun 2011 08:19:56 +0000

The bright sunshine of the tropics is great news for the group of mainly microscopic plants called algae. They prosper, especially in shallow waters, and as they photosynthesize, they produce sugars that attract herbivores to feast on them. Some species of algae grow as a covering on underwater substrates, but [...]

Lunar Cycles on the Reef

Travis Burke — Sat, 25 Jun 2011 07:56:26 +0000

Life on the coral reef is not only synchronized to the 24-hour cycle of night and day and to the annual seasonal changes seen most markedly in places such as the Red Sea. The orbit of the moon is also enormously important to life in the sea. It is the [...]

Fish Fighting Tactics

Travis Burke — Thu, 16 Jun 2011 06:09:49 +0000

If two closely matched fish fail to decide the issue by displays, an actual fight may develop, but this is relatively rare. Two aggressors must be very closely matched, with a great deal at stake, before they fight. How do fish make the transition from displaying to fighting? Sometimes the [...]

Reef Predator Hunting Techniques

Travis Burke — Mon, 13 Jun 2011 05:45:39 +0000

It's dog eat dog -- or fish eat fish -- on the reef. Predation by larger fish is a fact of life for members of the coral reef community, and this danger plays a large part in shaping many aspects of life there. Fish predators come in all shapes and [...]

Shrimps and Gobies Behavior

Travis Burke — Thu, 26 May 2011 02:02:32 +0000

Dramatic living arrangements between two completely different species are not confined to anemones and their clownfish lodgers.The relationship that sometimes occurs between shrimps and gobies is equally fascinating. How does the shrimp and goby relationship world? Some species of shrimps and gobies have a living arrangement that benefits both. The [...]

Sharp Minds on the Reef

Travis Burke — Tue, 17 May 2011 00:10:40 +0000

Exactly what constitutes intelligence in an animal is a controversial subject. It can also be a question that we regard subjectively, comparing the intelligence of an animal directly to our own, even though the animal is likely to have evolved to face very different pressures than us, pressures requiring a [...]

Planktivore Feeding Habits

Travis Burke — Fri, 13 May 2011 23:18:51 +0000

Tides and ocean currents deliver a continuous supply of microscopic plants and animals past coral reefs. This abundance of food supports a huge number of sea creatures, from the corals all the way up to enormous animals such as manta rays and the biggest of them all, the whale shark. [...]

The Coral Reef at Night

Travis Burke — Thu, 28 Apr 2011 20:28:22 +0000

The dark of night provides cover for a host of reef creatures, allowing them to emerge from their daytime shelters, safe from the depredations of the animals that threaten them. In many instances, the tables are turned - the diurnal hunters of invertebrates are themselves at great risk from the [...]

Defending Reef Territories

Travis Burke — Wed, 13 Apr 2011 17:17:36 +0000

Defending a territory is an expensive business. A territorial fish has access to all the food its patch can supply, but must spend a large amount of time and effort in driving away possible intruders.When the benefits outweigh the costs, as can happen at certain times of the year, or [...]

Territories on the Reef

Travis Burke — Sun, 10 Apr 2011 16:35:51 +0000

The coral reef is home to huge numbers of animals, each seeking to gather food, to shelter, and to find suitable space to breed. But these resources are scarce; there is rarely sufficient to go around so the competition is intense. Under these conditions, the only way that reef fish [...]

Mimicry - An Effective Defense

Travis Burke — Fri, 01 Apr 2011 15:04:28 +0000

Given a choice between tackling an angry moray eel or a small, inoffensive morsel of a fish, there are no prizes for guessing which one a predator is likely to opt for. But if the small fish in question can fool the predator into thinking it is a moray eel, [...]

Chemical Messages Underwater

Travis Burke — Tue, 29 Mar 2011 14:57:50 +0000

Animals detect the chemical cues that surround them using both their senses of smell (olfaction) and taste (gustation). Of these, olfaction is the more important, especially over long distance. Taste is used to assess things that are physically in contact with chemoreceptor cells. The underwater environment is a soup, full [...]

Eating on the Reef

Travis Burke — Sat, 26 Mar 2011 14:09:42 +0000

All animals must find food in order to maintain an energy supply to fuel their metabolic processes. Each individual faces competition for scarce food resources; only those that are consistently successful are able to grow and, in turn, reproduce. Finding sufficient food is not just about being able to fight [...]

Dominance Hierarchies on the Reef

Travis Burke — Sun, 27 Feb 2011 07:45:42 +0000

Although dominance hierarchies were first studied in domestic chickens -- hence the term "pecking order" -- many different kinds of animals, fish included, fight among themselves to see who is boss. In the wild, these dominance hierarchies are usually formed between conspecifics, but in aquariums a hierarchy can often develop [...]