Veterinary info

[finevet]

Frogs embryos are typically surrounded by several layers of gelatinous material. When several eggs are clumped together, they are collectively known as frogspawn. The jelly provides support and protection while allowing the passage of oxygen, carbon dioxide and ammonia. It absorbs moisture and swells on contact with water. After fertilization, the innermost portion liquifies to allow free movement of the developing embryo. Most eggs are black or dark brown and this has the advantage of absorbing warmth from the sun which the insulating capsule retains. The shape and size of the egg mass is characteristic of the species. The length of the egg stage depends on the species and the environmental conditions. Aquatic eggs normally hatch within one week when the capsule splits as a result of enzymes released by the developing larvae.

The larvae that emerge from the eggs, known as tadpoles (polliwogs), typically have oval bodies and long, vertically flattened tails. Tadpoles lack eyelids and have cartilaginous skeletons,lateral line systems, gills for respiration, and vertically flattened tails they use for swimming. From early in its development, a gill pouch covers the tadpole's gills and front legs. The lungs soon start to develop and are used as an accessory breathing organ. Tadpoles lack true teeth, but the jaws in most species have two elongated, parallel rows of small, keratinized structures called keradonts in their upper jaws. Tadpoles are typically herbivorous, feeding mostly on algae, including diatoms filtered from the water through the gills. Some species are carnivorous at the tadpole stage, eating insects, smaller tadpoles, and fish.

At the end of the tadpole stage, a frog undergoes metamorphosis in which its body makes a sudden transition into the adult form. This metamorphosis typically lasts only 24 hours, and is initiated by production of the hormone thyroxine. This causes different tissues to develop in different ways. The principal changes that take place include the development of the lungs and the disappearance of the gills and gill pouch, making the front legs visible. The lower jaw transforms into the big mandible of the carnivorous adult, and the long, spiral gut of the herbivorous tadpole is replaced by the typical short gut of a predator. The nervous system becomes adapted for hearing and stereoscopic vision, and for new methods of locomotion and feeding. The eyes are repositioned higher up on the head and the eyelids and associated glands are formed. The eardrum, middle ear, and inner ear are developed. The skin becomes thicker and tougher, the lateral line system is lost, and skin glands are developed.The final stage is the disappearance of the tail, but this takes place rather later, the tissue being used to produce a spurt of growth in the limbs. Frogs are at their most vulnerable to predators when they are undergoing metamorphosis.

[finevet]

Tardigrades also known as water bears or moss piglets. They are notable for being perhaps the most durable of known organisms; they are able to survive extreme conditions that would be rapidly fatal to nearly all other known life forms. They can withstand temperature ranges from −458 °F; −272 °C to about 300 °F; 150 °C, pressures about six times greater than those found in the deepest ocean trenches,ionizing radiation at doses hundreds of times higher than the lethal dose for a human, and the vacuum of outer space. They can go without food or water for more than 30 years, drying out to the point where they are 3% or less water, only to rehydrate, forage, and reproduce. They are not considered extremophilic because they are not adapted to exploit these conditions. This means that their chances of dying increase the longer they are exposed to the extreme environments, whereas true extremophiles thrive in a physically or geochemically extreme environment that would harm most other organisms.

[finevet]

Devil fish are most common in the Mediterranean Sea and can be found elsewhere in the Eastern Atlantic Ocean, off the southwest coast ofIreland and south of Portugal, and possibly in the northwest Atlantic. They predominantly prefer deep waters. It grows to a maximum recorded length of 5.2 metres, making it one of the largest rays. It possesses a spiny tail.  Devil rays feed on planktonic crustaceans and small schooling fish, which are trapped using the modified gill covers (branchial plates) responsible for its "devil-like" silhouette. The species is ovoviviparous: the young hatch from their eggs inside the mother's body and emerge later when they are more fully grown. Only a single live young which is called a pup is born at a time.

[finevet]

Paramecium

[finevet]

[finevet]

Coccidiosis is a parasitic disease of the intestinal tract of animals caused by coccidian protozoa. The disease spreads from one animal to another by contact with infected feces or ingestion of infected tissue. Diarrhea, which may become bloody in severe cases, is the primary symptom. Most animals infected with coccidia are asymptomatic, but young or immunocompromised animals may suffer severe symptoms and death.While coccidia can infect a wide variety of animals, including humans, birds, and livestock, they are usually species-specific.  Eimeria is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in cattle and poultry, among other animals.

Symptoms of Eimeria infection include bloody diarrhea due to intestinal epithelium dying off when a large number of oocysts and merozoites burst out of the cells. The severity of the disease is directly dependent on the number of infective Eimeria oocysts that are ingested by the bovine. In light infections the damage to the gut might only be minimal and be rapidly repaired as cells are rapidly replaced by the body. However, in heavy infections it may only take two weeks for many intestinal epithelial cells to be infected with either Eimeria meronts or gametocytes. These cause the epithelial cells to burst, which causes significant damage to the intestine epithelial layer, and releases blood, fluid, and electrolytes into the intestine.

Medications are available for the parasite; however, drug resistance is common, as well as possible drug residues in the meat once the animal is butchered. Vaccines have been developed, but one vaccine will only cover one species and not others. So far, the best practice is to vaccinate the chicks once they hatch from the egg so they are immune for life.