INTRODUCTION – ORGANIZATION OF COELOM The word coelom describes the body cavity that is internal space. But there can be difference in coelom true coelom will always be fluid filled lying between outer body wall and inner digestive tube. It arises between two layers of embryonic mesoderm and consist of most of the visceral organs.Hence […]
ORGANIZATION OF COELOM Read More »
What are Metazoans? Metazoans can be define as multicellular organisms or as cellular animal or more accurately simply as animals.They are holozoic multicellular organisms. Which are develop from embryo. Their body cells are generally organized in tissues and organs. [exception, porifera have cellular level of organization and coelenterates have tissue level of organization.] There gametes
THEORIES OF ORIGIN OF METAZOANS Read More »
What is a species? A group or class of animals or plants (usually constituting a subdivision of a genus) having a certain common and permanent characterstics which clearly distinguish it from other groups. BIOLOGICAL SPECIES CONCEPT REPRODUCTIVE ISOLATING MECHANISM PRE-ZYGOTIC POST-ZYGOTIC ECOLOGICAL HYBRID INVIABILITY TEMPORAL STERLITY BEHAVIORAL (barriers to isolation) REDUCED FITNESS OF HYBRID OFFSPRING
Environmental Limiting Factors Limiting Factors – All living things need food, water, shelter and space to survive. As long as organisms have all of these things available to them their population will continue to grow. However, populations can not grow forever. Some form of environmental resistance will stop the population’s growth. The form of environmental resistance
Environmental Limiting Factors Read More »
The rotifera are wheel animalcules. They are microscopic, bilaterally symmetrical, free living aquatic animals and pseudocoelomate animals.
ROTIFERA – STRUCTURE,LIFE HISTORY AND AFFINITIES Read More »
Key Characters of Holocephali General organization of Holocephalians External Features of Holocephali Fins and Locomotion Digestive System Respiratory System Circulatory System Nervous System Urinogenital System Fertilization Eggs and Development Sensory Organs Affinities of Holocephali Resemblances with the Elasmobranchs Primitive Shark’s Features of Holocephali Modern Shark’s Features of Holocephali Resemblances with Dipnoi Resemblances with Teleosts Primitive
Holocephali – General organization and affinities Read More »
The genus Lepisma comprises primitive insects that belong to the family Lepismatidae and order Zygentoma. The silverfish (L. saccharinum), the most well-known species in the genus Lepisma, is a worldwide species that prefers moist environments, hides in cracks, and is typically found in human homes. In some cases, it can become a household annoyance. Although
Lepisma (Silver fish) Read More »
Solifuges, or sun spiders, belong to the genus Galeodes. This genus has around 200 species that are distributed throughout Asia, southeastern Europe, and northern Africa. They are mostly nocturnal and found in dry environments, just like other solifuges. They are not as robust or as dark and contrastingly colored as some other solifuges, and they
The Atlantic horseshoe crab (Limulus polyphemus) is the only member of the genus Limulus that is still alive. Although several other species have been identified and subsequently assigned to other genera, the genus now has one fossil species credited to it. Classification of Limulus (Horseshoe crab) Phylum Arthropoda Jointed appendages. Class Arachnida Terrestrial or aquatic
Limulus (Horseshoe crab) Read More »
Male spiders (Araneus) in this genus are typically 1⁄3 to 1⁄4 the size of females, making them possibly the most blatant example of sexual dimorphism in the whole orb-weaver family.
Araneus (orb-weaving spiders) Read More »
The predatory arachnids known as scorpions (Palamnaeus) have eight legs, two grabbing pincers, and a slender, segmented tail that always ends with a stinger and is frequently carried in a distinctive forward curve over the back.
Palamnaeus (Scorpion) Read More »
Peripatus is zoologically very interesting, because it exhibits both arthropod and annelid characters as under. Peripatus is supposed to be the connecting link between Annelida and Arthropoda.
The class Diplopoda, which derives its name from the Latin mille, which means “thousand,” and pes, which means “foot,” is the formal term for the group of arthropods known as Julus (millipedes).
There are several centipede species in the genus Scolopendra that are found in both milder temperate regions and tropical regions of the planet. The species differ greatly in size and color. The majority of scolopendra are enormous centipedes
Scolopendra (Centipede) Read More »
Crabs in the genus Carcinus (Greek: Καρκίνoς Karkinos) include the significant invasive species Carcinus maenas and the Mediterranean Sea-endemic species C. aestuarii.
The little, sand-burrowing decapod crab species Hippa adactyla inhabits the shores of the Indo-West Pacific. It can be found in the swash area of the intertidal zone on bare sandy beaches.
Crocodile vs alligator vs gharial are large semi-aquatic reptiles belonging to the order Crocodilia. They differ greatly in appearance, habitat, behavior, and distribution, although having many traits in common, like as strong jaws, armored bodies, and a lifestyle related to water. Comprehending these differences facilitates precise identification and emphasizes their ecological significance. Physical Differences Between
Differences between Crocodile vs Alligator vs Gharial Read More »
Commonly identified as belonging to the genus Pagurus, Eupagurus is a genus of marine hermit crabs in the Paguridae family. They are distinguished by their asymmetrical, soft, and curled abdomens, which necessitate sheltering in empty snail shells. These decapods are found in marine habitats all over the world, frequently coexisting with sea anemones.
Eupagurus (Hermit crab) Read More »
The history of biological classification states that the Greek philosopher Aristotle categorized many creatures according to their environment, traits, etc. Later, in the 18th century, Swedish botanist Carolus Linnaeus established the Taxonomic Hierarchy Categories, a classification scheme that is still in use today.
What is Taxonomic Hierarchy? Read More »
Crayfish vs Lobster : Differences Explained – The fact that lobsters are sometimes referred to as crayfish in some places only serves to further confuse the two species. They do appear strikingly same, so it’s simple to make the mistake. Both have big pincers and robust exoskeletons, and they both live in water. In actuality, however, they belong to two distinct species.
Crayfish vs Lobster : Differences Explained Read More »
