How many fish species are there?

The first global census of life in the sea has logged some 230,000 species, however a ten year study on the subject performed by over 300 scientists warns of mass extinctions.

This ten year study has been the largest, most extensive study to attempt a stab at that age old question “Just how many fish are there in the sea?”

The ten year study, which was published today, is attempting to answer that question. It has analyzed the diversity, distribution and abundance of life in the world’s oceans. This study, dubbed The Census of Marine Life, hopes to give a ballpark estimate of the present marine life, and has estimated that there are more than 230,000 species living in our oceans.

“From coast to the open ocean, from the shallows to the deep, from little things like microbes to large things such as fish and whales,” explained Patricia Miloslavich of Universidad Simón Bolívar, Venezuela and co-senior scientist of the COML.
The study which was carried out also covers animals such as; crabs, plankton, birds, sponges, worms, squids, sharks and slugs.

Moe than 360 scientists from around the world got together and have spent the past ten years surveying 25 different regions, ranging from the Antarctic through the more temperate and tropical seas, to the Arctic, to attempt a head count of the different kinds of plants and animals.

The results of the study show that just about twenty percent of the marine species of the world are crustaceans such as lobsters, krill, barnacles, and crabs. Toss in Molluscs (such as squid and octopus) and fish (which include sharks) and that adds up to half of the number of species which are found in the oceans of the world.

The charismatic species often used in those ecological conservation campaigns – sea lions, turtles, whales and sea birds – make up less than 2% of the species in our world’s oceans.

Which is really interesting when you think about it.. We tend to only take notice of the species right on the surface, without really giving a second thought to those that dwell within the depths..

The surveys also pointed out the major areas of concern for the conservationist groups. “In every region, they’ve got the same story of a major collapse of what were usually very abundant fish stocks or crabs or crustaceans that are now only 5-10% of what they used to be,” explained Mark Costello of the Leigh Marine Laboratory, University of Auckland in New Zealand. “These are largely due to over-harvesting and poor management of those fisheries. That’s probably the biggest and most consistent threat to marine biodiversity around the world.”

The main threats that have been found up till now are; overfishing, degraded habitats, pollution and the arrival of invasive species. However, it was pointed out that more problems are on the horizon including; rising water temperatures, acidification thanks to global warming, and the expansion of areas unable to support life in the ocean.

Hopefully this survey will raise global awareness, and as a race, we can get together and start trying to preserve the abundant life, which is at the depths of our oceans.

Bermuda‘s first Lionfish Tournament resulted in just four participants returning with lionfish for the weigh-in. Although this might sound disheartening, it is actually happy news for Lionfish project leader Chris Flook of the Bermuda Aquarium, Museum and Zoo since it indicates a relative scarcity of lionfish in Bermuda waters.

Lionfish is an invasive species in the Caribbean where it lacks naturally predators and multiplies uncontrollably. In the Bahamas, female lionfish spawn twice a month. Lionfish Tournaments like the one just held in the Bermudas is a way to boost public awareness and decimate the number of lionfish in the Caribbean. A Lionfish Tournament held in the Bahamas a few weeks ago resulted in the catch of about 1,400 lionfish.

“If we’d caught 1,000 fish it would have been very concerning, because it means it’s happening here like everywhere else,” Flook explained. “It means we may be ahead of the game and are potentially managing the population here in Bermuda.”

However, Flook also said that one of the reasons why not many fish were caught Bermuda’s Lionfish Tournament could be that they were hiding in deep waters following the storm surge of the recent Hurricane Bill and Tropical Storm Danny.

Mr. Flook began the Lionfish Culling Programme last year to encourage divers and fishermen to hunt down the species. Organised by environmental group Groundswell, the ‘Eat ‘um to beat ‘um’ event also aimed to show how invasive lionfish can be utilized as a food source.

“I think everybody who tasted it was very for it. It’s a great tasting fish,” said Flook, as Chris Malpas, executive chef at the Bank of Butterfield, cooked up samples of speared lionfish at Pier 41.

“The tournament has got the message out and so now hopefully people might start asking for lionfish in restaurants and fishermen will bring them in rather than throwing them overboard.

By eating lionfish we will take the pressure off some of our commercial fish. Every one you take is one less eating our juvenile fish,” said Flook.

If you want to know more about spearfishing lionfish in Bermudas, contact the Bermuda Aquarium at 293-2727 ext. 127, or the Marine Conservation Officer at 293-4464 extension 146 or e-mail lionfish@gov.bm. The Marine Conservation Officer should also be contacted if you see a lionfish in Bermuda waters.

A previously unknown species of crustacean and two previously unknown species of annelid worms have been discovered during a cave dive near Lanzarote in the Canary Islands off the coast of northern Africa. The discoveries were made by a team of international scientists and cave divers exploring the Tunnel de la Atlantida – the longest submarine lava tube in the world.

The crustacean belongs to the genus Speleonectes in the class Remipedia, while the annelid worms are members of the class Polychaeta.

The crustacean has been named Speleonectes atlantida, after the cave system in which it lives. It looks a lot like its close relative Speleonectes ondinae which was discovered in the same lava tube in 1985. The two crustaceans may have diverged into separate species some 20,000 years ago after the Monte Corona volcano had erupted, forming the famous six-kilometre long lava tube.

Until quite recently, the class Remipedia was unknown to science. The first member of this class was found in 1979 by divers exploring a marine system in the Bahamas archipelago. Since then, 22 Remipedia species have been named and described. Most of them live in Central America, from the Yucatan Peninsula of Mexico through the north-eastern Caribbean. However, two species are instead found in caves in Lanzarote and Western Australia. The existence of these wayward species puzzles the scientists, since it is assumed that these small eyeless cave-dwellers would not be able to simply swim from the Caribbean to West Africa and Western Australia. One theory suggests that this class might be a very old crustacean group that was already widespread 200 million years ago. If this is true, the two species living off Lanzarote became isolated from the Caribbean group by the formation of the Atlantic Ocean.

As mentioned above, members of the class Remipedia live in dark submarine caves and have no eyes. Instead, they find their way around using long antennae. The heads of these predatory crustaceans are equipped with prehensile limbs and poisonous fangs.

The results of the lava cave exploration will be published in a special issue of the Springer journal Marine Biodiversity in September 2009.

The cave exploration team consisted of scientists from Texas A&M University and Pennsylvania State University in the USA, the University of La Laguna in Spain, and the University of Veterinary Medicine Hannover and the University of Hamburg, both in Germany.

An expansion of vertical seagrass occurring some 25 million years ago was probably what prompted seahorses to evolve from horizontal swimmers to upright creatures. If you live in vertical seagrass, an upright position is ideal since it allows you to stay hidden among the vertical blades.

This new idea is put forward in a report by Professor Beheregaray* and Dr Teske** published in the journal Biology Letters on May 6.

Sea horse picture from our Seahorse section.

Only two known fossils of seahorse have been found and this scarcity of fossil records has made it difficult for scientists to determine when seahorses evolved to swim upright. The older of the two fossils is “just” 13 million years old and no links between the two fossils and horizontally-swimming fish has been found.

“When you look back in time, you don’t see intermediate seahorse-like fish,” Beheregaray explains. There are however fish alive today that look like horizontally-swimming seahorses and Beheregaray and Teske have therefore studied them in hope of finding clues as to when seahorses made the transition from horizontal to vertical swimming.

By comparing DNA from seahorses with DNA from other species of the same family, Beheregaray and Teske were able to determine who the closest living relative to seahorses was.

“The pygmy pipehorses are by far the most seahorse-like fish on earth, says Beheregaray. “They do look like the seahorses, but they swim horizontally“.

When you have two closely related species, you can use molecular dating techniques to calculate when the two species diverged from each other. Beheregaray and Teske used a molecular dating technique that relies on the accumulation of differences in the DNA between the two species, and then used the two existing fossils to calibrate the rate of evolution of DNA in their molecular clock. By doing so, the two researchers could conclude that the last common ancestor of seahorses and pygmy pipehorses lived around 25 to 28 million years ago. At this point, something must have happened that led to the formation of two distinct species, and Beheregaray and Teske believe that this “thing” was the expansion of seagrass in the habitat where seahorses first evolved.

The time in history when seahorses arose, the Oligocene epoch, coincided with the formation of vast areas of shallow water in Austalasia. These shallow waters became overgrown with seagrass and turned into the perfect habitat for upright swimming seahorses that could remain hidden from predators among the vertical blades. The pygmy pipehorse on the other hand lived in large algae on reefs and had no use for an upright position, hence it continued to swim horizontally just like their common ancestor.

“The two groups split in a period when there were conditions favouring that split,” says Beheregaray. “It’s like us. We started walking upright when we moved to the savannahs. On the other hand, the seahorses invaded the new vast areas of seagrass.”

* Associate Professor Luciano Beheregaray of Flinders University

http://www.flinders.edu.au

** Dr Peter Teske of Macquarie University

http://www.macquarie.edu.au

Today we have the pleasure of bringing you a unique interview with Marc van Roosmalen which illustrates his situation and problems as he sees them. For those of you who aren’t familiar with who Marc van Roosmalen is, what he has done, and his present situation, I recommend reading this short introduction before reading the interview.

Thanks for taking the time to answer our questions Marc!

You have discovered a number of different species. Was finding one of them more special than finding the others? Is it still as much fun to find new species as it was when you found your first new species?

Marc G.M. van Roosmalen (MGMvR): Most fun but also most time and energy consuming for me was finding the ‘Land of Dermis’, where the relatives of Dermis occur – the baby black-capped dwarf marmoset that was delivered on my Manaus doorstep April 1996. With decades of experience in keeping all kinds of primates in halfway houses I knew right away that Dermis represented a new species of monkey and, undoubtedly, also a new primate genus. That event instantly took away the scepsis in me as a primatologist that nowadays it would be impossible to find new species of primates hitherto unknown to science. The quest that followed to find the monkey’s distribution somewhere in the huge Rio Madeira Basin had me stumbling into a Conan Doyle type of ‘Lost World’ – the Rio Aripuanã Basin – a hotspot of biodiversity that I soon recognized to be a totally new ecosystem within Amazonia, whose fauna and flora had never before been inventoried by naturalists, animal collectors, botanists and ornithologists alike. It took me a number of boat surveys to find Callibella humilis, a needle in a haystack as big as France. During innumerable surveys of the local rainforest and through interviews with the locals showing pictures of Dermis I happened to identify at least five other hitherto undescribed primates in the area.

Other highly memorable discoveries were those of some large terrestrial mammals whose existence I did not know of until I had close encounters with them while hiking alone through the forest. First spotting of a giant peccary (Pecari maximus) family silently crossing my trail while I was watching a group of Gray sakis in the canopy, or a group of dwarf peccaries (Pecari?) bumping literally into my feet while chasing one another through the undergrowth. And, back in camp, asking the locals what the hell the creature was that I had come upon that day…

Nowadays, under the Lula regime, it is not so much fun anymore to find new species because you run the risk to get caught in the ‘criminal’ act of collecting and transporting living evidence to support the validity of your find. To be able to publish it in a peer reviewed scientific journal you need at least to collect and deposit holotype material in a Brazilian museum. Without the proper collecting permits – a federal “license to kill” you can apply for in Brasilia, but never get granted – you seriously run the risk to be thrown in jail on accusation of what officials in Brazil call “biopiracy”. That is when you – like me – still collect, transport or keep alive any biological sample that could serve as holotype material or for DNA analysis in order to determine the phylogenetic and taxonomic status of your find. This way they make it impossible for Brazilian as well as foreign scientists to carry out biodiversity studies so needed for a sound nature conservation policy.

What do you feel when you finally find a species you have been looking for during a long time?

MGMvR: In the field you really feel yourself catapulted back in time, following the footsteps of the great naturalists such as Alexander von Humboldt, Wallace, Bates, Spruce, Spix & Martius. Little progress has been made in the Brazilian Amazon ever since my natural-history heroes collected and described a large part of the Amazonian flora and fauna. In this euphoria one tends to forget that times have changed. That having the great privilege to pick up the thread these icons left behind some 150-200 years ago is now considered a ‘criminal act against nature’.

Continue reading →

According to a new study from Uppsala University, the origin of fingers and toes can be traced back to a type of fish that inhabited the ocean 380 million years ago. This new finding has overturned the prevailing theory on how and when digits appeared, since it has long been assumed that the very first creatures to develop primitive fingers were the early tetrapods, air-breathing amphibians that evolved from lobed-finned fish during the Devonian period and crawled up onto land about 365 million years ago.

Lead author Catherine Boisvert[1] and co-author Per Ahlberg[2], both of Uppsala University in Sweden, used a hospital CT scanner to investigate a fish fossil still embedded in clay. “We could see the internal skeleton very clearly, and were able to model it without ever physically touching the specimen,” says Ahlberg. The scan revealed four finger-like stubby bones at the end of the fin skeleton. The bones were quite short and without joints, but it was still very clear that they were primitive fingers. “This was the key piece of the puzzle that confirms that rudimentary fingers were already present in the ancestors of tetrapods,” Catherine Boisvert explains.

The scanned fossil was that of a meter-long Panderichthys, a shallow-water fish from the Devonian period. Panderichthys is an “intermediary” species famous for exhibiting transitional features between lobe-finned fishes and early tetrapods, while still clearly being a fish and not a tetrapod. The specimen used was not a new finding; it had just never been examined with a CT scan before.

So, why have researchers for so long assumed that digits were something that evolved in tetrapods without being present in their fishy ancestors? The main reason is the Zebra fish (Danio rerio), a commonly used model organism when vertebrate development and gene function is studied. If you examine a Zebra fish, you will find that genes necessary for finger development aren’t present in this animal. Researchers therefore assumed that fingers first appeared in tetrapods and not in fish.

It should be noted that similar rudimentary fingers were found two years ago in a Tiktaalik, an extinct lobe-finned fish that lived during the same period as Panderichthys. Tiktaalik is however more similar to tetrapods than Panderichthys.

The Panderichthys study was published in Nature on September 21.

The Bolivian Amazon (picture by: Thomas van den Berk)

The Bolivian River Dolphin has finally been graced with the acknowledgement that it is, in fact, a separate species from its close relative, the Amazon River Dolphin. Lighter in color, smaller, and having more teeth, are only a few of the things that separate this newly named species apart from the others. It is able to move its head side to side; something other dolphins can not do,  to manuever through flooded forests during heavy rains and flooding.

Unfortunately the Bolivian River Dolphin, like all dolphins, is facing a questionable future do to pollution, fishing, industrialization, damming, and deforestation. 1,500 dolphins are caught and killed each year by fishermen to be used as bait. Hopefully, unlike the newly extinct Yangtze River dolphin in China, the Bolivian River Dolphin will be able to saved by awareness and conservation efforts.

for a complete article on the Bolivian River Dolphins visit: http://www.telegraph.co.uk/earth/main.jhtml?xml=/earth/2008/04/29/eadolph129.xml

A new species of Tetra has been found in the drainage from the Portuguese River in Venezuela. The scientific name Hyphessobrycon otrynus. Ortynus is Greek for “spur,” which describes, the large bone spur-like hooks that curve from each side of the anal fin on the adult males of the species. Further information on this new species is lacking, but will be provided as research is gathered.

For a free excerpt from the Zootaxa 1747: 61-68 (April 2008) by RICARDO C. BENINE & GUILHERME A. M. LOPES (Brazil) That describes a little aboutH. Ortynus visit:  http://www.mapress.com/zootaxa/2008/f/z01747p068f.pdf