Costa Rica

A United States based world fisheries conservation association is gunning for punishment to be dished out, after a sportfishing boat was attacked by a commercial Venezuelan tuna purse seining boat and a helicopter off of Costa Rica’s coast.

This incident was reported, and is well documented, on The Billfish Foundation’s website: http://www.billfish.org.

The past August 1st, at just about 3PM, a United States sportfishing boat, the Silver-Rod-O, owned by Gary Carter, a TBF member, of Duluth, GA., was assaulted by the other craft, Venezuelan flagged tuna purse seiner La Rosa Mistica (The Mystic Rose), while minding its own business some 15 miles off the shores of Garza, Costa Rica.

According to Gary, the Silver-Rod-O was minding its own business, trolling around a school of spinner dolphin for yellow fin tuna and billfish, when a helicopter off of the La Rosa Mistica, began to circle overhead.

“We were celebrating one of our guest’s first-ever sailfish release, when the seiner veered from its course and headed directly toward our boat. The helicopter then began making passes over the anglers and as the seiner came closer and began setting its net, the helicopter started dropping incendiary devises around the Silver-Rod-O and the school of spinners.”

“Several explosives landed within 50 meters of the boat. The purse seiner continued to power straight toward our boat,” Carter said, “It was threatening to either encircle us in their net or to plow us into the sea unless we abandoned the school of dolphin. Rather than endanger our guests, we retreated and watched and listened as the La Rosa Mistica closed the net and its crew obnoxiously celebrated its victory.”

Just goes to show you, be careful where you fish! Hopefully, the Costa Rican authorities will look into the matter, and justice will be served.

Brachypopomus gauderio is not the only electric knifefish recently described from South America, U.S. researchers John P. Sullivan* and Carl D. Hopkins** have described another member of the genus Brachyhypopomus and given it the name Brachyhypopomus bullocki.

This new species is named in honour of Theodore Holmes Bullock, a renowned neurobiologist who died in 2005. Bullock was a pioneer of the comparative neurobiology of both invertebrates and vertebrates and is credited with the first physiological recordings from an electroreceptor and for championing electric fishes as a model system in neurobiology. The electric organ discharge waveform of Brachyhypopomus bullocki is biphasic, 0.9–1.6 milliseconds in duration, and the pulse rate varies from 20–80 Hz.

Brachyhypopomus bullocki is found throughout the Orinoco Basin in Venezuela and
Colombia. It can also be encountered in the in the Rio Branco drainage of Guyana and the Roraima State of Brazil, as well as in the upper part of Rio Negro near the mouth of Rio Branco.

Brachyhypopomus bullocki appears to prefer clear, shallow, standing water in open savannah, or savannah mixed with stands of Mauritia palm. It has also been collected among plants growing along the banks of small pools fed by streams. In Rio Negro, a specimen was found amongst palm leaf litter near the outlet of a black water stream.

Brachyhypopomus bullocki distinguishes itself from its close relatives by having larger eyes (comparative to the head), a short abdomen, and distally enlarged poorly ossified third and fourth branchiostegal rays.

The paper can be downloaded from Cornell University.

* John P. Sullivan, Department of Ichthyology, The Academy of Natural Sciences, Philadelphia. Email: sullivan@ansp.org

** Carl D. Hopkins, Department of Neurobiology and Behavior, Cornell University, New York. Email: cdh8@cornell.edu

A strange algae plume has turned the normally crystal clear Caribbean Sea around the Virgin Islands green down to a depth of roughly 80 feet (25 metres) and sharply decreased visibility in these popular dive waters. How and if the plume will have any long-term effect on the region’s marine life remains unknown.

Tyler Smith, assistant professor at the Center for Marine and Environmental Studies at the University of the Virgin Islands, said that when he went diving Tuesday the visibility inside the plume was no more than 10 feet (3 metres). Below 80 feet, the water was just as clear as normally.

The reason behind the extraordinary plume can be found in South America, in the Orinoco River which flows through Venezuela before reaching the Atlantic Ocean. When the Orinoco outflow is larger than normal, the vast amounts of nutrient-rich freshwater from Venezuela cause a major algae bloom in the nearby ocean. Mixed fresh- and saltwater is lighter than seawater and will therefore rise to the top of the water column.

“It’s very stable, so it just sits there,” Smith explains.

Carried by currents, the algae plume has now spread from the South American east-coast to the Caribbean Sea and can currently be seen not only off the British and U.S. Virgin Islands but in Puerto Rican waters as well. The first patch was noticed by Smith and his colleagues in the waters off St. Croix on April 9.

When the amount of photosynthesising alga increases in a region, it attracts all sorts of organisms that feed on algae and make it possible for these populations to boom as well. The algae plume around the Virgin Islands supports an entire food chain of marine life, including plankton, jellyfish, crustaceans and fish. It is not dangerous to swim or scuba dive in, but some people might dislike the high density of jellyfish.

“This is an event that occurs every year, but we haven’t seen it come this far north,” says Trika Gerard, marine ecologist with the U.S. National Oceanic and Atmospheric Administration (NOAA). In a stroke of good luck, a NOAA research vessel was scheduled to research reef fish in these waters from April 7 to April 20 – right at the peak of the unexpected plume.

To find out more about how the plume effects marine life, the Caribbean Fisheries Management Council is urging anyone who goes out fishing in the green plume to report their location, target species and success rate of each trip. According to local fishermen the fishing is always awfully bad when the water is green, but this has not been scientifically researched yet and all data is of interest.

You can reach the Caribbean Fisheries Management Council by calling (787) 766-5927. Their website is http://www.caribbeanfmc.com.

The catfish L239 has finally been described by science and given a proper name: Baryancistrus beggini. Ichthyologists Lujan, Arce and Armbruster described the species in a paper[1] published in the journal Copeia[2].

Baryancistrus beggini lives in Venezuela and Colombia; in Rio Guaviare and at the confluence of Rio Ventuari and Rio Orinoco. The researchers found the fish in crevices amongst boulders. By analysing stomach contents, they were able to learn that this catfish feeds on periphyton and associated microfauna growing on rocks. (Periphyton is a mixture of algae, heterotrophic microbes, cyanobacteria, and detritus that can be found attached to submerged surfaces, e.g. stones, in most underwater ecosystems.)

In the aquarium trade, L239 is known as Blue panaque or Blue-fin panaque. The name beggini was given by Lujan and his colleagues in honour of Chris Beggin, the owner of an aquarium fish store in Nashville, USA who funded the research. The species has been placed in the genus Baryancistrus, but this might have to be corrected in the future as we learn more about the tribe Ancistrini.

Baryancistrus beggini sports a uniformly dark black to brown base colour with a blue sheen and the abdomen is naked. Along each side of the body you can see a distinctive keel above the pectoral finns; a keel formed by the strongly bent first three to five plates of the midventral series. The body also features two to three symmetrical and ordered predorsal plate rows and the last dorsal-fin ray is connected to the adipose fin.

Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Siluriformes
Family: Loricariidae
Subfamily: Hypostominae
Tribe: Ancistrini
Genus: Baryancistrus

New species: Baryancistrus beggini

The cichlid genus Crenicichla now has two new described members: Crenicichla tesay and Crenicichla mandelburgeri.

Crenicichla tesay

Crenicichla tesay lives in the Paraná River drainage and was described by Argentinian ichthyologists Jorge Casciotta and Adriana Almirón. The fish was caught in the Iguazú River upstream of Iguazú falls in Argentina, an environment characterized by falls and pools with clear and rapidly flowing water. The bottom in this habitat consists of stones, mud and sand.

The name Crenicichla tesay is derived from the Guaraní word for tears; the fish displays a tear-shaped suborbital stripe. You can distinguish Crenicichla tesay from its close relatives by the existence of a serrated posterior preopercle border, the number of scales on the E1 row, the length of the snout, and the colour pattern which consists of a suborbital stripe, 4–6 dark blotches and numerous irregularly scattered dots on the sides of the body.

The description has been published in the journal Revue Suisse de Zoologie[1]. For more information, see the paper: Casciotta, J and A Almirón (2008) Crenicichla tesay, a new species of cichlid (Perciformes: Labroidei) from the río Iguazú basin in Argentina. Revue Suisse de Zoologie 115, pp. 651–660.

Crenicichla mandelburgeri

Just like Crenicichla tesay, this newly described cichlid hails from the Paraná River drainage. It was described by Swedish ichthyologist Sven Kullander and named Crenicichla mandelburgeri in honour of Paraguayan ichthyologist Darío Mandelburger.

The Crenicichla mandelburgeri specimens were collected from two different environments. Some lived in the rapids of a large stream (5-10 meters wide and up to 1 meter deep) with turbid, brownish water. Others lived in a much smaller stream (up to 3 meters wide) with shallower brown water where both velocity and transparency fluctuated. In this environment, the bottom consisted of stones and sand and was generally without any plants.

Young Crenicichla mandelburgeri cichlids feature numerous narrow vertical bars along the side, which changes into an irregular dark horizontal band as the fish matures. You can also distinguish Crenicichla mandelburgeri from other crenicichlas by the distinct caudal blotch, the number of scales in the lateral row and in the E1 row, the lower jaw (which is longer than the upper), and the serrated preopercular margin.

For more information, see the paper: Kullander, SO (2009) Crenicichla mandelburgeri, a new species of cichlid fish (Teleostei: Cichlidae) from the Paraná river drainage in Paraguay. You can find it in Zootaxa 2006: 41–50.[2]

Crenicichla

Crenicichla is the cichlid genus where you can find the largest number of described species, about 75 species. They live on the South American continent where they inhabit freshwater rivers, streams, pools and lakes. The richest variation of species is encountered in the Amazon region, but you can find Crenicichla cichlids as far north as Guyana, Venezuela and Colombia and as far south as Uruguay and central Argentina where the water can become fairly cold in the winter.

This post will introduce a number of new catfish species, a couple of tetras and an a few cichlid species.

Let’s start with the cichlid species. The species known as Apistogramma sp Mamore have been scientifically described by Wolfgang Staeck and Ingo Schindler and named A. erythrura. It is a small species and the largest speciemen that have been found so far was 30.8 mm SL. (just over 1.2 inch). It seems to feed on small invertebrates. Thy can be found in waters with the following conditions pH 5.2–6.4; electrical conductivity <10–20 μS/cm; total and temporary hardness < l°dH; water temperature 25.1–31.0°C. They are cave spawners and can be bred in aquariums. The male guards a territory which can contain several females. The females guard the fry.

Scientists Felipe Ottoni and Wilson Costa from Brazil have in the latest issue of the journal Vertebrate Zoology described nine new species of Australoheros cichlids from southern Brazil[1].

Australoheros autrani, A. Barbosae, A. ipatinguensis, A. macacuensis, A. muriae, A. paraibae, A.s robustus, A. saquarema

New tetras

Two new species of flag tetra have been described[2]. Both species originates in Venezuela. The new species Hyphessobrycon paucilepis and H. tuyensis was described by Carlos García-Alzate, César Román-Valencia and Donald Taphorn in the latest issue of the journal Vertebrate Zoology. At the same time they recognize three other valid species: H. diancistrus, H. fernandezi and H. sovichthys.

Hyphessobrycon paucilepis originates from the small drainages in Lara state, northern Venezuela. H. tuyensis from the Tuy River drainage in northern Venezuela

New catfish species

Brazilian scientists Héctor Alcaraz, Weferson da Graça and Oscar Shibatta have in the latest issue of the journal Neotropical Ichthyology named a new species of bumblebee catfish from Paraguay Microglanis carlae as attribute to ichthyologist Carla Pavanelli[3]. The species is found in moderately fast flowing water in Paraguay River drainage.

Brazilian ichthyologists Luisa Sarmento-Soares and Ronaldo Martins-Pinheiro have described three new Tatia species bringing the total number of described species up to twelve[4]. The three new species described are T. caxiuanensis (named after the Floresta Nacional de Caxiuanã.), T. meesi (named after Gerloff Mees) and T. nigra (named after its dark color)

T. caxiuanensis is found in the Floresta Nacional de Caxiuanã, T. meesi in Essequibo River drainage in Guyana and T. nigra in the Uatumã and Trombetas river drainages.

Marcelo Rocha, Renildo de Oliveira and Lúcia Py-Daniel have described a new Gladioglanis catfish, Gladioglanis anacanthus, which can be found in the Aripuanã River in central Brazil[5].

Lúcia Py-Daniel and Ilana Fichberg have described a new whiptail catfish, Rineloricaria daraha. This new species is found in the Rio Daráa in the Rio Negro drainage which have given the species its name[6].