Whois & Analysis for sharks-world.com

Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head.

Modern sharks are classified within the clade Selachimorpha (or Selachii) and are the sister group to the rays.

However, the term "shark" has also been used for extinct members of the subclass Elasmobranchii outside the Selachimorpha, such as Cladoselache and Xenacanthus, as well as other Chondrichthyes such as the holocephalid eugenedontidans.

Under this broader definition, the earliest known sharks date back to more than 420 million years ago.

Acanthodians are often referred to as "spiny sharks"; though they are not part of Chondrichthyes proper, they are a paraphyletic assemblage leading to cartilaginous fish as a whole.

Anatomy is the branch of biology concerned with the study of the structure of organisms and their parts.

Anatomy is inherently tied to embryology, comparative anatomy, evolutionary biology, and phylogeny, as these are the processes by which anatomy is generated over immediate (embryology) and long (evolution) timescales.

Human anatomy is one of the basic essential sciences of medicine.

Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parents".

Reproduction is a fundamental feature of all known life; each individual organism exists as the result of reproduction.

There are two forms of reproduction: asexual and sexual.

Conservation biology is the management of nature and of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction and the erosion of biotic interactions.

It is an interdisciplinary subject drawing on natural and social sciences, and the practice of natural resource management.

Modern humans (Homo sapiens, primarily ssp.

Homo sapiens sapiens) are the only extant members of Hominina tribe (or human tribe), a branch of the tribe Hominini belonging to the family of great apes.

They are characterized by erect posture and bipedal locomotion; manual dexterity and increased tool use, compared to other animals; and a general trend toward larger, more complex brains and societies.