Three new species of saddled loricariid catfishes, and a review of Hemiancistrus, Peckoltia, and allied genera (Siluriformes)

(Figs 2–4). CORBIDI 14685, an adult male (Figs 2–4) from 13.5806 S, 75.2449 W (WGS84), Chicchobamba, upstream of Represa Negrayccassa, upper drainage of the Huaytará river, 3900 m, Provincia Huaytará, Región Huancavelica, Peru, collected by A. Catenazzi, V. Vargas García, and M. Jaico Huayanay

We describe a new species of Telmatobius from the Pacific slopes of the Andes in central Peru. Specimens were collected at 3900 m elevation near Huaytará, Huancavelica, in the upper drainage of the Pisco river. The new species has a snout–vent length of 52.5 ± 1.1 mm (49.3–55.7 mm, n = 6) in adult females, and 48.5 mm in the single adult male. The new species has bright yellow and orange coloration ventrally and is readily distinguished from all other central Peruvian Andean species of Telmatobius but T. intermedius by having vomerine teeth but lacking premaxillary and maxillary teeth, and by its slender body shape and long legs. The new species differs from T. intermedius by its larger size, flatter head, and the absence of cutaneous keratinized spicules (present even in immature females of T. intermedius), and in males by the presence of minute, densely packed nuptial spines on dorsal and medial surfaces of thumbs (large, sparsely packed nuptial spines in T. intermedius). The hyper-arid coastal valleys of Peru generally support low species richness, particularly for groups such as aquatic breeding amphibians. The discovery of a new species in this environment, and along a major highway crossing the Andes, shows that much remains to be done to document amphibian diversity in Peru.

The Tropical Andes are characterized by a large diversification of the aquatic frogs of the genus Telmatobius Wiegmann, 1834. Sixty-two species are currently recognized in this genus (AmphibiaWeb 2014; Aguilar and Valencia 2009; Frost 2014; including species previously assigned to Batrachophrynus Peters, 1873). The altitudinal distribution of Telmatobius ranges from 1000 m to 5400 m (De la Riva and Harvey 2003; Seimon et al. 2007), and its longitudinal distribution extends from the equator (T. niger Barbour & Noble, 1920, whose populations have been extirpated in Ecuador; Merino-Viteri et al. 2005) to 29°S, on the eastern slopes of the Argentinean Andes (T. contrerasi Cei, 1977). Twenty-eight species of Telmatobius are distributed in Peru (Lehr 2005; AmphibiaWeb 2014), but of these only five [T. arequipensis Vellard, 1955; T. intermedius Vellard, 1955; T. jelskii (Peters, 1873); T. peruvianus Wiegmann, 1834; T. rimac Schmidt, 1954] are known to occur in the hyper-arid coastal valleys that drain directly into the Pacific Ocean.

During October 2012 we made several surveys for the Biodiversity and Monitoring Assessment Program of the Smithsonian Conservation Biology Institute’s Center for Conservation Education and Sustainability (Catenazzi et al. 2013a; Catenazzi et al. 2013b). During one of these surveys, we found a population of Telmatobius in the upper drainage of the Huaytará river (Region of Huancavelica), a tributary of the Pisco river in the Pacific slopes of the central Peruvian Andes. Individuals of this population possess traits that do not correspond to the morphological characteristics of other species found in the arid coastal valleys of central Peru (Fig. 1), namely T. rimac to the north and T. intermedius to the south (Vellard 1951; Schmidt 1954; Lehr 2005). Therefore, here we describe the new species and provide a diagnosis to differentiate it from congeneric forms.

Source: Read Full Artical at - zookeys

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New study finds Alaskans familiar with ocean acidification, not aware of risks to fisheries

New research published in Marine Policy from the first Alaska-focused study on public understanding and awareness of ocean acidification risk shows that Alaskans are three times more aware of ocean acidification than Americans in general.  However, Alaskans have difficulty seeing ocean acidification as an immediate risk, and the direct risks to Alaska’s fisheries are still not well understood. The research, “Gauging perceptions of ocean acidification in Alaska,” can be read online.

In Alaska, the impacts of ocean acidification have the potential to be even worse than “other coastal communities because of an accelerated rate of change in ocean chemistry, and statewide reliance on commercial and subsistence fishing. Accurately evaluating ocean acidification risk directly influences the ability to respond to change. The research builds on earlier NOAA-led research showing that communities in southeast and southwest Alaska are more at risk than other areas of the state because of their heavy reliance on fisheries expected to be impacted by ocean acidification.

“We wanted to learn the best way to provide Alaskans with the information they need to properly respond to ocean acidification,” said Lauren Frisch, who led the study and is a research associate at the University of Alaska Fairbanks Ocean Acidification Research Center. “The first step was to determine where there are gaps in the understanding of ocean acidification so that we can then work to fill them in.”

                      Crab fishing
A new study shows that Alaskans know about ocean acidification, but are not aware of the risk it poses to Alaskan fisheries. (NOAA)

Some 2000 Alaskans received a questionnaire in September, 2013. Questionnaires asked about each respondent’s role in the state's fishing industry as well as their belief in, understanding of, and concern about ocean acidification. The questionnaire’s response rate was 18 percent, which is high for studies of this nature. Results showed limited understanding of how Alaska will be uniquely impacted by ocean acidification. For example, only 28 percent of Alaskans believe that ocean acidification would have a greater impact on Alaska than other states in the United States.  Alaskans affiliated with the state’s fishing industry are not significantly more concerned about ocean acidification than those unaffiliated, and only 33 percent believe that ocean acidification will decrease revenue for fisheries. Finally, ocean acidification is perceived as a distant risk.  

“It can be difficult to think about ocean acidification as an immediate risk with all of the other challenges that we’re facing,” said Jeremy Mathis, who is the co-lead author on the paper describing the study’s results and an oceanographer at NOAA’s Pacific Marine Environmental Laboratory. “We really have to work harder to get the message out to stakeholders around Alaska that ocean acidification is something that they need to consider sooner rather than later.”

With a better idea of what Alaskans understand about this issue, the next step is to shape public education in a way that facilitates a long-term discussion of ocean acidification drivers and impacts, as well as mitigation and adaptation strategies.

“Moving forward, we need to figure out how to enhance this understanding that acidification is not uniform, and therefore adaptation plans will be more successful if they are local.  Educating communities with local examples about their specific risk could help foster this understanding.  The best thing we can do is provide vulnerable communities the toolset to evaluate risk themselves,” said Frisch.

Source: NOAA

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New research shows ocean warming poses "immediate threat" to keystone reef-building coral in the Caribbean

New research published in The Proceeding of the Royal Society - Biological Sciences provides new insights on the threat  ocean warming poses on coral growth in Mesoamerican barrier reefs.  The research, partially funded by CPO's Climate Monitoring program, used laboratory experiments to examine the adverse effects of ocean warming and acidification, and showed that the warming predicted by the IPCC for the end of the 21st century produced a five-fold decrease in coral calcification - the process by which corals produce calcium carbonate (CaCO3) and build reefs.

“The reef-building coral Siderastrea siderea exhibits parabolic responses to ocean acidification and warming,” is part of on-going work of NOAA-funded researcher Dr. Justin Ries that is looking at various aspects of climate variability, change, and ocean acidification on coral growth.  Dr. Ries and colleagues have been examining long term coral reef growth patterns at one of the largest barrier reefs in the world, off the coast of southern Belize. The research aims to create100 year records of coral growth at this reef by examining growth rates and environmental factors. As part of this work, Dr. Ries and his team found substantially decreasing growth rates over the last several years, at the same time that ocean acidification and temperature have been increasing.

Massive Starlet Coral (Siderastrea siderea) Image courtesy: D. Gordon E. Robertson via Creative Commons

This new research, led by post-doctoral researcher Dr. Karl Castillo, was designed to isolate the effects increasing ocean acidification and temperature had on Siderastrea sidereal, an important keystone and reef building coral species at the reef. By extracting coral colonies and returning them to the lab, researchers were able to design separate experiments around increasing temperature and decreasing ocean pH, and measure the coral response. While the most adverse effects on corals may arise from both acidification and temperature warming, researchers wanted to better understand the specific responses to these individually, which could aid efforts to predict and potentially mitigate the impacts of changing ocean conditions on coral.

They found that both ocean acidification and ocean warming had a “parabolic effect” on this important coral species. This means that while moderate decreases in the pH of seawater and moderate rises in temperature led to increases in coral building, in both cases researchers found a “tipping point” at which the coral calcification rates started decreasing. For ocean acidification, researchers recreated seawater conditions that would occur from the atmospheric carbon dioxide concentration from pre-industrial up through the present, the predicted end-of-century value, and up to six times the present condition. They found the “tipping point” at which calcification started leveling off and finally decreasing was actually well past the acidifications that would be expected by the end of century. For this particular species, they concluded, ocean acidification expected over the next century alone may not have a significant adverse effect.

Figure 1: Rates of reef-building calcification observed during the experiment for (left panel) increasing levels of ocean acidification and (right panel) temperatures ranging from 25C to 32C.

For warming ocean temperatures, however, the results were very different.  For the temperature experiments, researchers grew the coral colonies in temperatures from 25C to 32C, which covers the range of annual minimum and maximum temperatures of ocean temperatures recorded near the reef over 2002-2014, as well as annual average seawater temperatures expected over the next century. Thus the researchers were hoping to capture how the coral responds to the year to year variability seen now as well as what general conditions are predicted to by like by the end of the century. They found that while reef-building calcification rates increased for corals at 28C relative to 32C, skeletal building dropped off dramatically – nearly 80% - in corals growing at 32C. This parabolic response indicates that for this important reef building species, ocean warming over the next few decades could be an immediate serious threat, as conditions pass what the research found to be a species tipping point. Researchers note that the actual reef will experience changes in both stressors – ocean acidification and ocean warming – together over the next century, and will continue to work to understand how this and other reefs may respond.

You can watch a YouTube video on this and other aspects of Dr. Ries coral reef research here:  



Source: CRO

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Dolphins are attracted to magnets: Add dolphins to the list of magnetosensitive animals, French researchers say

Bottlenose dolphins

Add dolphins to the list of magnetosensitive animals, French researchers say. Dolphins are indeed sensitive to magnetic stimuli, as they behave differently when swimming near magnetized objects. So says Dorothee Kremers and her colleagues at Ethos unit of the Université de Rennes in France, in a study in Springer's journal Naturwissenschaften -- The Science of Nature. Their research, conducted in the delphinarium of Planète Sauvage in France, provides experimental behavioral proof that these marine animals are magnetoreceptive.

Magnetoreception implies the ability to perceive a magnetic field. It is supposed to play an important role in how some land and aquatic species orientate and navigate themselves. Some observations of the migration routes of free-ranging cetaceans, such as whales, dolphins and porpoises, and their stranding sites suggested that they may also be sensitive to geomagnetic fields.

Because experimental evidence in this regard has been lacking, Kremers and her colleagues set out to study the behavior of six bottlenose dolphins in the delphinarium of Planète Sauvage in Port-Saint-Père. This outdoor facility consists of four pools, covering 2,000 m² of water surface. They watched the animals' spontaneous reaction to a barrel containing a strongly magnetized block or a demagnetized one. Except from this characteristic, the blocks were identical in form and density. The barrels were therefore indistinguishable as far as echolocation was concerned, the method by which dolphins locate objects by bouncing sound waves off them.

During the experimental sessions, the animals were free to swim in and out of the pool where the barrel was installed. All six dolphins were studied simultaneously, while all group members were free to interact at any time with the barrel during a given session. The person who was assigned the job to place the barrels in the pools did not know whether it was magnetized or not. This was also true for the person who analyzed the videos showing how the various dolphins reacted to the barrels.

The analyses of Ethos team revealed that the dolphins approached the barrel much faster when it contained a strongly magnetized block than when it contained a similar not magnetized one. However, the dolphins did not interact with both types of barrels differently. They may therefore have been more intrigued than physically drawn to the barrel with the magnetized block.

"Dolphins are able to discriminate between objects based on their magnetic properties, which is a prerequisite for magnetoreception-based navigation," says Kremers. "Our results provide new, experimentally obtained evidence that cetaceans have a magenetic sense, and should therefore be added to the list of magnetosensitive species."

Source: Springer Science+Business Media

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The science behind swimming: From whales to larvae, common principles at work in swimming

Whale and diver (stock illustration). Using simple hydrodynamics, researchers were able to show that a handful of principles govern how virtually every animal -- from the tiniest fish to birds to gigantic whales propel themselves though the water. Credit: © James Thew / Fotolia

At nearly 100 feet long and weighing as much as 170 tons, the blue whale is the largest creature on the planet, and by far the heaviest living thing ever seen on Earth. So there's no way it could have anything in common with the tiniest fish larvae, which measure millimeters in length and tip the scales at a fraction of a gram, right?

Not so fast, says L. Mahadevan, the Lola England de Valpine Professor of Applied Mathematics, of Organismic and Evolutionary Biology, and of Physics.

Using simple hydrodynamics, a team of researchers led by Mahadevan was able to show that a handful of principles govern how virtually every animal -- from the tiniest fish to birds to gigantic whales propel themselves though the water. The study is described in a September 14 paper in Nature Physics.

"What we wanted to investigate was how the speed of an organism changes as a function of how large it is, how quickly it moves and how much it moves," Mahadevan said. "To resolve that in detail, however, is very complex, because there is a great deal of differences in morphology and what parts of the body different creatures use to swim. The question is: Is there anything in common across all these organisms? The answer, we found, is yes."

In an effort to uncover those common principles, Mahadevan working with a postdoctoral fellow in his group , Mattia Gazzola, and a colleague Mederic Argentina from the University of Nice, began by trying to unpack the physics of how different creatures swim.

"The traditional approach to swimming phenomena is to take a certain specimen and accurately characterize it via experiments and/or simulations, and try to generalize from there, but it is very hard to strip out specific biological effects from general principles," Gazzola said. "We instead thought that while swimmers exhibit a huge diversity in shapes and kinematics, at the end of the day they all live in the same media, water.

"Therefore we thought that if a unifying mechanistic principle existed, it had to lie in the constraints that the flow environment poses to all its inhabitants," he continued. "And this is a purely physical problem, much easier to solve since it is not affected by biological vagaries. What I like about this paper is that in one line of algebra we derived a compact formula that accounts for 50 years of experiments. This is an example of how powerful minimal modeling can be."

"The basic relationship we wanted to understand was how the input variables -- namely the size of the organism, the amount an organism moves and how quickly it moves -- control the output variable, which is effectively the speed at which it moves," Mahadevan explained. "What we found is that there is a specific relationship, which can be described by in terms of a simple scaling law with two limits."

The first, which corresponds to creatures moving at intermediate speeds, describes situations where the bulk of the resistance is caused by skin friction, because water "sticks" to the organism's body. At faster speeds, Mahadevan said, the resistance organisms face largely comes from pressure that builds up in front of and around them, which is described by the second limit.

"While it wasn't a surprise that the resistance changed at organisms moved faster, the fact that those challenges could be so simply described was interesting and provocative, because we are talking about organisms that range in size from a few millimeters to the size of a blue whale," Mahadevan said.

Armed with those observations, Mahadevan and colleagues turned to a host of empirical observations that had been made over the past 50-plus years. When those data were plotted on a graph, the researchers found that the swimming speed of virtually every organism, from fish larvae to frogs to birds, amphibians and even whales, could be described by one of the two equations.

The same also held true, Mahadevan said, when Gazzola created complex computer models to solve the governing equations of fluid dynamics to describe how different organisms swim.

"What is particularly interesting is that all the organisms essentially reach the hydrodynamic limits of performance," he said. "Our simple theory, which doesn't distinguish in any detailed way between something like a blue whale and fish larvae, except in the parameters of how large you are, much you move and how quickly you move, can describe all this diversity. That suggests there are general principles at work here."


Source: Harvard University

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