PATTERN OF FEEDING AND DIGESTION IN LOWER INVERTEBRATES Pattern of feeding and digestion in lower invertebrates :- Every organism needs energy to perform its basic metabolic function. This energy can be obtain from food and sun. As sun is a universal source of energy but only autotrophic organism can obtain energy from sun. The energy […]
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INTRODUCTION The phylum Bryozoa, or Polyzoa, or Ectoprocta are the greatest and most common of the three lophophore phyla. Colonial sessile animals such as Cnidaria and Ectoprocta were for a long time confused by early naturalist sea plants and named them as zoophytes. In 1827 Grant found that ectoprocta are highly organised than true polyps
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INTRODUCTION The Entoprocta or Endoprocta are group of small sessile aquatic animals. In which the body cavity is believed to be pseudocoel. They were formerly include in the phylum Bryozoa which however are true coelomate animals. Members of phylum Entoprocta were known as early as 1774, when Pallas describe a colony of Pedicellina. In 1870
INTRODUCTION Phoronida are long and thin worm like organisms. All phoronids reproduce sexually. Some of them are hermaphrodite while other aredioecious. Fertilization is internal as well as external. Intermediate larval stage is present. This species generally live in coastline of mostly all oceans and seas except the Antarctic ocean. Phoronids are generally algae feeder and
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HYDROSTATIC MOVEMENT Hydrostatic movement :- Different organism needs different things for their survival and reproduction. To obtain food and defence itself from predator they must move. Their are different mechanism for movement one of them is hydrostatic movement. Hydrostatic movement occur when dominantly muscles are involved in their movement many organism show such kind of
INTRODUCTION Locomotion in Protozoa – Moving ones body is an essential need of any organism. Some organism are sessile while other moves at very high speed. Some organisms moves very slowly such as amoeba or euglena where as other can move fastest example leopard. There is a vast diversity of organism on the basis of
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
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
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
The rotifera are wheel animalcules. They are microscopic, bilaterally symmetrical, free living aquatic animals and pseudocoelomate animals.
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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
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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
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
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.
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.
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
