A few years back scientists became aware that Amazonian manatees (Trichechus inunguis) migrate from shallow to deep water each year, starting in October or November when the dry season makes the water level decrease in their favoured habitat. A team of Brazilian and British researchers now claim have found out why these mesmerizing creatures undertake a perilous journey to get to a habitat that doesn’t have much to offer food wise.

By studying manatees living in the Mamiraua and Amana Sustainable Development Reserves in north-western Brazil, the team found out that if the manatees wouldn’t move, the animals would be become stranded in the shallow water and exposed to predators such as caimans and jaguars.

“Amazonian manatees migrate to a habitat that doesn’t offer easy living conditions in order to flee from a habitat that becomes inhospitable,” says team-member Dr Eduardo Moraes Arraut from the National Institute for Space Research in Sao Paulo, Brazil.

A dangerous voyage
In order to reach deeper waters, the manatees must pass through narrow bottlenecks in the landscape where they easily fall prey to predators – including humans. Hunting manatee is illegal in Brazil but the local people have a long tradition of eating the meat.

Once the manatees reach their destination, it isn’t much of a relief either. Due to a lack of aquatic plants in their new home, they are forced to go without food for several months.

“When you have two options that are not good, you choose the one that is less bad,” Dr Arraut explains, adding that the harshness of the low-water conditions surprised him.

Modern technology and ancient knowledge
In order to learn more about the elusive manatees, the international research team asked local inhabitants about the movements of the manatees, and placed modern radio tracking devices on 10 individual manatees. What they found was that the Amazon landscape forces the manatees to migrate through a type of narrow lakes known as rias, a type of submerged river valleys.

Dr Arraut now wishes to track manatees in other parts of the Amazon to find out if they are facing similar obstacles as the populations in Mamiraua and Amana.

The findings have been published in the Journal of Zoology.

http://www.zsl.org/info/publications/

A gentle giant
The Amazon manatee is one of the smallest species of manatee but can nevertheless reach a length of 9.2 ft (2.8 m) and weight 800-1200 lbs (360-540 kg). It is only found in the Amazon River basin, in the countries Brazil, Peru, Colombia, Guyana and Ecuador.

During the high-water season (mid-May to late June), the Amazon manatees live in quiet lakes (so called varzeas) that form within river flood plains in the Amazon. In this hospitable environment, they feast on aquatic plants and typically consume 8% of their weight in greens each day. For a manatee weighing 800 lbs, that means 64 lbs – almost 30 kg!

Picture is depicting a manatee in Florida (not an Amazonian Manatee)

A new species of the genus Chromaphyosemion has been described by Jean-Françcois Agnèse and his co-authors in a paper* published in a recent issue of the journal Zootaxa.

The new species, who has been given the name Chromaphyosemion campomaanense, belongs to the A. calliurum species group and was collected from the the Ntem River drainage in southern Cameroon. The name campomaanense is derived from Campo Ma’an National Park, the place where the fish was found.

According to the study, Chromaphyosemion campomaanense inhabits small streams and shallow pools in the rainforest. It prefers to stay close to the river bank and stays away from deeper areas with more fast moving water.

Chromaphyosemion campomaanense differs from its close relatives by displaying an asymmetrical colour pattern on the caudal fin consisting of a yellow lower margin and a white upper margin. The body is dark blue and adorned with red spots forming horizontal rows towards the head. Posteriorly, the rows merge into vertical rows. When researchers studied the genetic make-up of this fish they found that its karyotype distinguished it from the other species of the A. calliurum species group; it was
caracterized by unusually high number of chromosomes and arms compared.

The main focus of the study was to examine the molecular phylogeny of the members of the A. calliurum species group. Using a 760 base-pair fragment of the mitochondrial cytochrome b gene, researchers found the group to be composed of 10 species:

A. ahli
A. australe
A. calliurum
A. campomaanense
A. celiae
A. edeanum
A. franzwerneri
A. heinemanni
A. lividum
A. pascheni

* Agnèse, J-F, R Brummett, P Caminade, J Catalan and E Kornobisi (2009) Genetic characterization of the Aphyosemion calliurum species group and description of a new species from this assemblage: A. campomaanense (Cyprinodontiformes: Aplocheiloidei: Nothobranchiidae) from Southern Cameroon. Zootaxa 2045, pp. 43–59.

Wild-caught pets are often recommended against, since the harvest of wild caught specimen may deplete wild populations. In the Brazilian rainforest, the harvesting of popular aquarium species such as cardinal tetras have however helped prevent deforestation and made it possible for local residents to earn a living without resorting to logging, mining, cattle ranching, and slash-and-burn agriculture.

“All this is very counter-intuitive,” says Scott Dowd, an Amazon biologist at the New England Aquarium who has been researching the dark acidic waters of Rio Negro, a major Amazon tributary in Northern Brazil, for the past two decades. “You would think biologists would not want to take fish out of the rainforest. But the fish are the key to miminizing deforestation. The people’s other economic options – timber harvest, cattle ranching and gold mining – are environmental disasters.”
The Rio Negro region has been a major fish exporter for over half a century and 60 percent of local populations rely in this source of income for their sustenance. Since deforestation is known to be detrimental to the survival of financially valuable fish species like the cardinal tetra fish, the Brazilian government has protected the Rio Negro rainforest from logging and burning – at least until now. The situation may be about to change dramatically as more and more aquarium shops switch from wild-caught fish to farm-raised specimens. Wild-caught specimens are used to the dark, soft and highly acidic water conditions of Rio Negro, while farm-raised fish tend to be acclimatized to common tap-water conditions (i.e. clear water that is not very soft or acidic) and therefore easier to keep.

To prevent the market for wild-caught Rio Negro fish from collapsing, Dowd is participating in a “Buy a Fish, Save a Tree” campaign. “The local fisheries look like they are headed for collapse”, Down explains. “But there’s hope that this threat can be addressed. If you ask fish hobbyists if they care about the environment, a very high percentage say they care about it deeply.”

Dowd hopes that the “Buy a Fish, Save a Tree” branding will help Brazilian fish harvesters to benefit from the growing trend of cause labelling, such as Fair Trade and FSC (Forest Stewardship Council).

Another important step in making wild-caught Rio Negro fish a popular alternative to farmed-raised specimens is to adapt them to normal aquarium conditions, and the New England Aquarium is therefore helping local fishermen to efficiently acclimatize wild-caught tetras to a pH-value around 7.0.

Dowd also hope to take advantage of the Internet, by assigning lot numbers to every batch of aquarium fish caught in Rio Negro. “Imagine if you could go online and see a video of the actual fisherman who caught your tropical fish, says Dowd. “I want hobbyists to know directly how their choices can affect people thousands of miles away and how they can make a contribution to saving the rainforest. Things don’t look good, but we can begin to turn all of this around.”

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’.

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Born in the Netherlands in 1947, Marc van Roosmalen is a Brazilian primatologist of Dutch birth living in Manaus, Brazil. After studying biology at the University of Amsterdam he did four years of doctoral fieldwork in Suriname studying the Red-faced Spider Monkey. Since then, van Roosmalen has devoted his life to the scientific exploration of the South American flora and fauna.

Marc van Roosmalen is described as a hand-on naturalist and has spent long periods of time doing research work in the Amazonian rainforest, while simultaneously producing prolific amounts of scientific papers, books, reviews, and wildlife documentaries. His work has led to the discovery and description of several new species, such as Callibella humilis, the dwarf marmoset, the second smallest monkey in the world, and Lecythis oldemani, a tree belonging to the Brazil Nut family. From 1986 to 2003, van Roosmalen served as senior scientist at the National Institute for Amazonian Research (INPA) under the Brazilian Ministry of Science and Technology.

Parallel to his research work, van Roosmalen is a dedicated conservationalist trying to protect the Brazilian rainforest from destruction by humans. During the late 1980s, he launched “The Center for the Rehabilitation and Re-introduction of Endangered Wildlife” in the federal Rio Cuieiras Nature Reserve; a centre where all kinds of animals, but especially monkeys confiscated from the illegal pet trade, were rehabilitated in the local rain forest. In 1999, he founded the NGO “Amazon Association for the Preservation of High Biodiversity Areas” (AAPA) and began purchasing areas of pristine rainforest in regions harboring extremely high biodiversity and/or animals and plants new to science.

For his outstanding work in South America, van Roosmalen has received several honors and was knighted as Officer in the Order of the Golden Ark by Prince Bernhard of the Netherlands in 1997. At the turn of the millennium, van Roosmalen was selected as one of the worldwide recognized “Heroes for the Planet” by Time Magazine.

You can read about van Roosmalen’s current predicament in our interview with him which is found here. More information can also be found in this Wired article and this article published by the Smithsonian institution.

“For if there are out there big tree-dwelling, ground-dwelling and even aquatic mammals not known to science – a dwarf tapir, a giant peccary, a white deer, a dwarf manatee, another river dolphin, to name a few – what do we really know about its flora and fauna? Very Little. About its ecology – the utterly complex web of relationships between plants and animals? Even less. Then what do we know about the sustainability of this ecosystem? Absolutely nothing.”

– Marc van Roosmalen