Cricetinos (Cricetinae) are a subfamily of rodents, commonly known as hamsters (a Germanism). Nineteen current species have been identified, grouped into seven genera. Most are native to the Middle East and southeastern United States. All species are characterized by expanding pockets, called abazones, located inside the mouth, which run from the cheeks to the shoulders. Because they are very easy to breed in captivity, they are widely used as laboratory animals and as pets.. Characteristics. Life expectancy: from one and a half to three years, although there are known cases in which they have lived up to four years, but it depends on the species.. Adult weight: 30-40 g in Russian; 100-180 g the golden hamster.. Length: 8-10 cm Russian; 15-18 cm golden hamster.. Sexual maturity: two and a half months.. Enters into heat: (after two months) every four days.. Gestation time: between eighteen and twenty-one days for Russian and fifteen to seventeen days for golden hamsters.. Breeding per birth: average from seven to eight. Nineteen offspring have been reported.. Age at weaning: between three and four weeks.. There are different sizes and colors: golden hamsters, syrians, dwarfs, etc. Their adorable appearance and tiny body make these pets very popular. But hamsters are not as loving as they seem. These small rodents are quite delicate and have quite demanding needs...
Read More
Fish (from the Latin pisces) are primarily aquatic vertebrate animals, generally ectothermic (they regulate their temperature from the environment) and gill-breathing. They are usually covered by scales, and are equipped with fins, which allow their continuous movement in aquatic environments, and gills, with which they capture the oxygen dissolved in water. The Pisces group is not a taxon because it would be paraphyletic. Fish are abundant in both salt and fresh water, with species found from mountain streams (e.g., gobies), as well as from the deepest ocean (e.g., swallowtails).. Foods prepared with fish are an important source of food for humans. They can be large from wild specimens, or raised in a similar way to livestock (see aquaculture). Nowadays the so-called sport fishing is becoming more and more popular. Fish have played an important role in many cultures throughout history, ranging from religious deities to book and movie themes.. The specialty of zoology that deals specifically with fish is called ichthyology.. GENERAL CHARACTERISTICS OF FISH. They are aquatic vertebrates.. They have a bony or cartilaginous skeleton.. They have fins to move in the water: even or odd. Your body is covered with dermal scales or denticles.. They breathe through gills the oxygen dissolved in the water.. They have variable temperature.. They reproduce by eggs. They leave the eggs in the...
Read More
Birds are vertebrate, warm-blooded animals that walk, jump or stand on their hind limbs only, while their forelimbs have evolved into wings that, like many other unique anatomical features, allow them, in most cases, to fly, although not all of them fly. They have a body covered with feathers and, the birds sensu stricto, a horny beak without teeth. To reproduce, they lay eggs that incubate until they hatch.. They are aerial animals that are mainly characterized by being the only species to have feathers. A more elaborate definition would indicate that they are warm-blooded vertebrates more closely related to reptiles than to mammals and that they have a four-chambered heart (as do mammals), modified winged forelimbs (a trait shared with bats), a hard-shelled egg, and sharp vision, the main sense on which they rely for environmental information. Their sense of smell is not very developed and their hearing range is limited. Most birds are diurnal. More than 1,000 extinct species have been identified from fossil remains.. Characteristics. The birds emerged as flying, arboreal and warm-blooded creatures, with front legs adapted for flight and hind legs for perching. This basic plan has been modified so much in the course of evolution that in some ways it is difficult to recognize.. Among flying birds, the wandering albatross has the largest wingspan,...
Read More