Fish of Monfragüe national park, Extremadura, Spain


This July 2015 video from the Guadalora river in Andalusia, Spain shows Tropidophoxinellus alburnoides (or: Squalius alburnoides) fish. This species lives a bit more to the north, in Extremadura, as well.

Still 13 April 2016 in Extremadura, Spain. We had arrived at Monfragüe national park. Before blogging about birds in that park, first about fish: based on a park sign, and this source.

Indigenous fish species in the park waters include the two barbel species Iberian barbel and Luciobarbus bocagei.

Also autochthonous: Iberian nase. And Iberochondrostoma lemmingii. Both species are related.

And Tropidophoxinellus alburnoides. And Squalius pyrenaicus.

All these autochthonous species mentioned here are endemic to Spain and Portugal.

This video from Spain says about itself:

20 January 2015

Brown trout (Salmo trutta), Iberian barbel (Luciobarbus bocagei) and Iberian nase (Pseudochondrotoma polylepis) ascending the vertical-slot fishway model built in Hydraulics Laboratory (Centre for studies and experimentation on public works, CEDEX).

Fish species of Monfragüe, introduced from elsewhere, include carp.

And Prussian carp (introduced from, originally, Asia).

And largemouth bass, pumpkinseed and black bullhead, all three from North America.

And northern pike. And zander.

And big wels catfish.

And much smaller eastern mosquitofish.

Marine animals helping each other, video


This video says about itself:

Jonathan Bird’s Blue World: Cleaning Stations (HD)

22 April 2016

Jonathan explores cleaning stations on the reef, where animals get cleaned of parasites and infection by other animals. Some examples shown are anemones and anemonefish (clownfish), wrasses, shrimp, manta rays, moray eels, Goliath groupers, sea turtles and barracuda. This episode was filmed in many locations such as Malaysia, the Philippines, Yap, Australia’s Great Barrier Reef and the Caribbean.

How marine animals live together, video


This video from the USA says about itself:

Jonathan Bird’s Blue World: Symbiosis In The Sea (HD)

15 April 2016

In this webisode Jonathan explores different types of symbiosis in the ocean, including mutualism, commensalism and parasitism, and how animals use it for survival.

Young trout freed in Dutch streams


This video shows some of the 10,000 baby sea trout freed on 2 April 2016 in brooks in Drenthe province in the Netherlands. As the fish grow up, they will migrate downstream, until they reach the Wadden Sea. They will live at sea for years, until they will return to the fresh water to spawn.

Brook lampreys are back in Dutch stream


This 1 April 2016 shows brook lampreys spawning in the Reusel brook in North Brabant province in the Netherlands.

They had become extinct there in the 1960s.

Recently, however, Reusel water quality has improved. Meanders and pebbly soil, lamprey habitat, came back. Last year, brook lampreys were reintroduced from the only other place in North Brabant where they still lived, the Dommel stream. This spring, brook lampreys are spawning in the Reusel again, for the first time after decades.

How clownfish live together peacefully


This video, recorded in India, says about itself:

21 August 2012

Symbiosis, including anemonefish & clownfish. Part 18 of my DVD, “Reef Life of the Andaman“.

From ScienceNews:

In the Coral Triangle, clownfish figured out how to share

by Sarah Zielinski

11:41am, April 1, 2016

Clownfish and anemones depend on one another. The stinging arms of the anemones provide clownfish with protection against predators. In return, the fish keep the anemone clean and provide nutrients, in the form of poop. Usually, several individual clownfish occupy a single anemone — a large and dominant female, an adult male and several subordinates — all from the same species. But with 28 species of clownfish and 10 species of anemone, there can be a lot of competition for who gets to occupy which anemone.

In the highly diverse waters of the Coral Triangle of Southeast Asia, however, clownfish have figured out how to share, researchers report March 30 in the Proceedings of the Royal Society B. Anemones in these waters are often home to multiple species of clownfish that live together peacefully.

From 2005 to 2014, Emma Camp, of the University of Technology Sydney and colleagues gathered data on clownfish and their anemone homes from 20 locations that had more than one species of clownfish residents. In 981 underwater survey transects, they encountered 1,508 clownfish, 377 of which lived in groups consisting of two or more fish species in a single anemone.

Most of those cohabiting clownfish could be found in the waters of the Coral Triangle, the team found, with the highest levels of species cohabitation occurring off Hoga Island in Indonesia. There, the researchers found 437 clownfish from six species living among 114 anemones of five species. Every anemone was occupied by clownfish, and half had two species of the fish.

In general, “when the number of clownfish species exceeded the number of host anemone species, cohabitation was almost always documented,” the researchers write.

The multiple-species groups divvied up space in an anemone similar to the way that a single-species group does, with subordinate fish sticking to the peripheries. That way, those subordinate fish can avoid fights — and potentially getting kicked off the anemone or even dying. “Living on the periphery of an anemone, despite the higher risk of predation, is a better option than having no host anemone,” the team writes.

These multi-species groups might even be better for both of the clownfish species, since they wouldn’t have to compete so much over mates, and perhaps even less over food, if the species had different diets.

This isn’t the first time that scientists have found cohabitation to be an effective strategy in an area of high biodiversity. This has also been demonstrated with scorpions in the Amazon. But it does show how important it is to conserve species in regions such as this, the researchers say — because losing one species can easily wipe out several more.

Bull shark in Dutch lake?


In this 31 March 2016 video, a Dutch wildlife warden talks about the Kolkven lake in the Kampina nature reserve in North Brabant province. Recently, a photo was made of a shark‘s fin protruding out of the water there. Probably, a bull shark, a species often held in aquariums, has been freed in the lake after growing too big for the aquarium.

Stay tuned, the warden says.

However, it turned out to be an April Fools’ Day joke. So, a ´bullshit´ shark.

This video says about itself:

9 March 2015

This documentary looks at the bull shark (Carcharhinus leucas), also known as the Zambezi shark or, unofficially, as Zambi in Africa and Nicaragua shark in Nicaragua. It is a requiem shark commonly found worldwide in warm, shallow waters along coasts and in rivers. The bull shark is known for its aggressive nature, predilection for warm shallow water, and presence in brackish and freshwater systems including estuaries and rivers. This is the full bull shark documentary.

Bull sharks can thrive in both saltwater and freshwater and can travel far up rivers. They have even been known to travel as far up the Mississippi River as Illinois, although there have been few recorded freshwater attacks. They are probably responsible for the majority of near-shore shark attacks, including many attacks attributed to other species.

Unlike the river sharks of the genus Glyphis, bull sharks are not true freshwater sharks, despite their ability to survive in freshwater habitats.