FLORA AND FAUNA OF BETWEEN RIVERS: REPRESENTATIVE SPECIES - BIOLOGY - 2025

The flora and fauna of Entre Ríos is represented by species such as the ñandubay, the irupé, the princho, the manduví, among others. Entre Ríos is one of the central provinces of Argentina, out of a total of 23 that exist in that country. This region, together with Corrientes and Misiones, is part of Argentine Mesopotamia.

Around 15% of the territory is made up of flooded lands and islands, which are surrounded by streams and rivers, such as the Paraná and Uruguay. The relief is flat, crossed by numerous watercourses. Regarding the climate, the north is subtropical, without the presence of the dry season. To the south it is of the temperate Pampean type.

Princho Source: Dario Sanches Irupe Source: TitiNicola

In the province there are more than 40 protected nature reserves. In these, the extensive and rich biodiversity of flora and fauna is protected in a natural way, by the rivers that surround the areas and by environmental laws of the country.

Flora of Entre Ríos

Ñandubay (

This tree is found in Brazil, Argentina, Uruguay, and Paraguay. In these countries, they tend to grow in the higher areas of the plains. Also, it could survive in those regions that periodically flood.

The height of this legume could be between 3 and 13 meters. The trunk is short, with a rough, thick and grayish-brown bark. In addition, it presents transverse and horizontal fissures, thus forming irregular plates.

The cup is flattened in shape. In the nodes of the branches there are thorns, approximately 2 centimeters long. These are conical and are distributed in pairs. The leaves of the ñandubay are small and deciduous, thus being able to be fasciculate or alternate.

The wood of Prosopis affinis is brown in color, with pink tones. Because it is very resistant to the elements, it could be used to make structures that will be exposed to the open air. In addition to this, it is a melliferous species and its pods are part of the diet of the animals that forage in the region.

Irupé (

The irupé or yacaré yrupe is an aquatic plant found in the basins of the Paraguay and Paraná rivers.

From the rhizome, which is submerged, the roots emerge. These are fibrous and adhere to the bottom of the body of water. Long and flexible petioles sprout from the root system, where the large floating leaves are located.

The leaves are covered in a cuticle, which helps repel water. At the bottom they have a porous tissue, presenting intercellularly filled cavities with air, thus facilitating the flotation of the plant. The structures of the plant that are submerged have thorns, thus protecting it from predators.

The irupé flower is characterized by a particular aroma, similar to that of pineapple. It grows on a stem that is up to 2.5 centimeters wide. The floral bud is elongated and white in color, with a pink calyx with 4 sepals. The outer petals have air chambers, which help the flower to float.

The fruit is a berry covered with thorns. It is globose and brown in color, containing numerous oval seeds inside.

Curupí (

This tree belongs to the Euphorbiaceae family. It is found in South America, especially in Uruguay, Argentina, Paraguay, Bolivia and Brazil. In Argentina, it lives in the delta areas of the Paraná River, where it is part of the gallery forest.

The curupí is a semi-deciduous tree species, with a wide, low and globose crown. One of the characteristics of its branches is that they tend to grow almost to the ground. Regarding the fruits, these are red, an aspect that makes them very striking.

Sapium haematospermum is used to make a homemade glue, known as glue. For this, the latex that emanates from the bark is used, after it is cut. However, latex can be highly irritating to the eyes and skin.

On the other hand, wood is light, which is why it is used in making boxes, carvings and as plywood. Curupí seeds have been used as a poison to exterminate rats.

Fauna of Entre Ríos

Princho (

The princho is a gregarious bird that inhabits both open and semi-open spaces in Brazil, Paraguay, Uruguay, Bolivia and Argentina.

The total length of this animal is approximately 34 centimeters. Although there is not a very marked sexual dimorphism, because the appearance of the male and the female is very similar, the female is usually a little larger than the male.

The upper body is dark brown, with some white stripes. In contrast, the throat, belly, chest and rump are white. The tail is wide, long and deep brown, with a white tip.

On the face, the eyes and a beak in yellow or orange tones stand out, as is the beak. Also, this species has a reddish-orange crest.

The guira cuckoo, as this species is also known, is an opportunistic predator that hunts its prey on the ground or captures it between branches. Their diet is based on insects, worms, frogs, tadpoles, and mice. It also feeds on small birds, their eggs, or chicks.

Collared Kingfisher (

This heart-shaped bird, which belongs to the Cerylidae family, is distributed from southern Texas to Tierra del Fuego. In Argentina, this species is found in almost the entire territory, especially in the Entre Ríos province.

The size of this animal is approximately 36 centimeters long. On the head, which is large, there is a semi-forelock and a straight and sharp bill.

The plumage on the back and head is bluish-gray, while the chest is brown. The ventral and subcaudal areas of the wing may be white, brown or reddish. On the other hand, a white stripe stands out on the neck, in the shape of a necklace. The female is identical to the male, except for having a slate blue breast.

On the Argentine coasts, the collared kingfisher can be seen posing alone on the branches, waiting to be able to dive and hunt their prey. Their diet is based on frogs, insects, crustaceans and also small fish.

Manduví (

The manduví is a fish that is part of the Auchenipteridae family. The adult species measures around 40 centimeters, weighing a maximum of 1 kilogram. It is characterized by its great swimming ability, thus allowing it to quickly escape from its predators.

The coloration is pinkish white and, due to the fineness of its skin, a black and branchy pattern, characteristic of this animal, can be observed through it. It has a long, flattened head.

At the front of the body it has a dorsal fin. While, at the other end, close to the anal area, it has a small adipose fin. In a lateral view of the king jaw, as the Ageneiosus valenciennesi is also called, a prominent and somewhat drooping belly can be seen.

References

1. Entreriostotal (2019). Entre Ríos Province. Recovered from entreriostotal.com.ar.
2. Kewscience (2019). Victoria cruziana. Recovered from powo.science.kew.org.
3. S. Schulenberg (2019). Guira Cuckoo (Guira guira). Neotropical Birds Online. Cornell Lab of Ornithology, Ithaca, NY, USA. Recovered from neotropical.birds.cornell.edu.
4. Montecito de Lovera educational nature reserve (2001). Large kingfisher. Recovered from cerrito.gob.ar.
5. Ministry of Production and Labor of Argentina (2019). Manduvi. Recovered from agroindustria.gob.ar.
6. Wikipedia (2019). Entre Rios, province. Recovered from en.wikipedia.org.