Virtual Dissection Project
Presented by Henryk Viana
The Digestion of an Earthworm
The Common Earthworm
Our Objectives are:
- Learn the generalities of the earthworm digestive system.
- Discuss the organs of the earthworm digestive system.
- Analyze the function of the earthworm digestive system.
The General Information
Organs of Digestive System
- Mouth: the opening where the earthworm intakes soil.
- Buccal Cavity: the space where soil is in preparation for digestion.
- Pharynx: the junction between the buccal cavity and the esophagus.
- Esophagus: the smooth muscular tube which pushes the soil into the intestine.
- Crop: the area that helps in the movement of soil and temporally stores food.
- Gizzard: the area where the soil and food is crushed in order to extract the nutrients.
- Intestine: the tubular structure that extract nutrients from the soil.
Function of Digestive System
Extra Information About the Common Earthworm
Earthworm Taxonomy:
- Kingdom: Animalia
- Phylum: Annelida
- Class: Clitelatta
- Order: Haplotaxida
- Family: Lambricicdae
- Genus: Lumbricus
- Species: Terrestris
- Earthworm have actually evolved in response to environmental stress and have adapt to survive in harsh conditions.
- The main evolutionary adaptation relates to its roughly cylindrical bodies that are perfectly suited for wiggling or burrowing through tight environments.
- A worm's sense of touch is also an evolutionary adaptation that allows it to sense things like increased moisture, approaching predators and temperature changes.
- · Earthworms are divided into four groups, called ecotypes, each of which has a different life style.
- Compost earthworms. As their name would suggest, these are most likely to be found in a compost bin. They prefer warm and moist environments with a ready supply of fresh compost material. They can very rapidly consume this material and also reproduce very quickly. Compost earthworms tend to be bright red in color and stripy. Compost earthworm species include Eisenia fetida and Eisenia veneta
- . Epigeic earthworms live on the surface of the soil in leaf litter. These species tend not to make burrows but live in and feed on the leaf litter. Epigeic earthworms are also often bright red or reddy-brown, but they are not stripy. Epigeic earthworm speices include Dendrobaena octaedra, Dendrobaena attemsi,Dendrodrilus rubidus, Eiseniella tetraedra, Heliodrilus oculatus, Lumbricus rubellus,Lumbricus castaneus, Lumbricus festivus, Lumbricus friendi, Satchellius mammali.
- Endogeic earthworms live in and feed on the soil. They make horizontal burrows through the soil to move around and to feed and they will reuse these burrows to a certain extent. Endogeic earthworms are often pale colours, grey, pale pink, green or blue. Some can burrow very deeply in the soil. Endogeic earthworm species include Allolobophora chlorotica, Apporectodea caliginosa, Apporectodea icterica,Apporectodea rosea, Murchieona muldali, Octolasion cyaneum and Octolasion tyrtaeum.
- Anecic earthworms make permanent vertical burrows in soil. They feed on leaves on the soil surface that they drag into their burrows. They also cast on the surface, and these casts can quite often be seen in grasslands. They also make middens (piles of casts) around the entrance to their burrows. Anecic species are the largest species of earthworms in the UK. They are darkly coloured at the head end (red or brown) and have paler tail. Anecic earthworm species include Lumbricus terrestris and Apporectodea longa.
- During agricultural processes, earthworms can improve the soil fertility, creating air pockets, in areas where the soil is too compact for human agriculture.
- Earthworm in the soil make minerals more accessible, so plants may improve their growth.
The Circulatory System of a Perch
The Ordinary Perch
Our Objectives are:
- Learn the generalities of the perch circulatory system.
- Discuss the organs of the perch circulatory system.
- Analyze the function of the perch circulatory system.
The General Information
Organs of the Circulatory System
- Sinus Venosus: chamber where low oxygenated blood from the veins collects.
- Atrium: Blood from the sinus venosus enters here awaiting to be pumped into the ventricles
- Ventricle: Blood from the atrium enters this main pump awaiting to be expelled to the bulbus arteriosus.
- Bulbus Arteriosus: Funnel where low oxygenated blood will be pumped towards the gills.
Function of the circulatory system
Extra Information About the Ordinary Perch
- · Kingdom: Animalia
- · Phylum: Chordata
- · Superclass: Osteichthyes
- · Class: Actinopterygii
- · Subclass: Neopterygii
- · Infraclass: Teleostei
- · Order: Perciformes
- · Family: Percidae
- · Genus: Perca
Perches have many fine and sharp teeth. Due to its ability to crossbreed and the similar morphology among different varieties of perches, the perch has survived and adapted over time to many different environments. Zooplankton is the primary food source for young and larval perch, which increased their survival rate.
Their microhabitat is usually along the shore among reeds and aquatic weeds, docks, and other structures. They are less abundant in deep and clear open water or unproductive lakes.In North America, perch are an extremely important food source for birds. Perch are commonly active during the day and inactive at night.Perch are most often found in schools. Their vision is necessary for schooling and the schools break up at dusk and reform at dawn. The schools typically contain 50 to 200 fish, and are arranged by age and size in a spindle shape.
The Perch have been commercially harvested over 100 years in United States and Canada over the Great Lakes area. Tons of perches with a value of millions of dollars are captured and sold each year.Also Fishing of perches is very popular as sport activity in North America and the rest of the world.
The Respiratory System of Arthropods
The Regular Grasshopper
The grasshopper is a terrestrial arthropod of the suborder Caelifera in the order Orthoptera. Species that change color and behavior at high population densities are called locusts.
Our Objectives are:
- Learn the generalities of the grasshopper respiratory system.
- Discuss the organs of the grasshopper respiratory system.
- Analyze the function of the grasshopper respiratory system.
The General information:
Grasshopper breath through a network of branching tracheal tubes extending through the body. Their respiratory system is adapted to terrestrial life. Other arthropods have respiratory systems adapted to aquatic life.
Organs of the Respiratory System:
- Tracheae: are air-filled tubes which open at the surfaces of the thorax and abdomen through pairs of spiracles.
- Spiracle valves: open to allow oxygen and carbon dioxide exchange.
- Tracheoles: found at the end of the tracheal tubes, are insinuated between cells and carry oxygen throughout the body.
Function of the Respiratory System:
The main function of the respiratory system is to perform air exchange to allow for oxygenation. Air enters and leaves the tracheal tubes through spiracles which are small openings located along the side of the body. Air exchange happens through the tracheoles where oxygen is delivered to the tissue.
Extra Information About the Regular Grasshopper
- Kingdom: Animalia
- Phylum: Arthopoda
- Subphylum: Hexapoda
- Class: Insecta
- Order: Orthoptera
- Suborder: Caelifera
Grasshopper Evolution:
The ancestors of grasshoppers evolved over 200 millions year ago, during the Triassic period, when the first reptiles appeared on Earth. they are indeed adapted to fly very rapidly and without hesitation to capture their prey or escape from predators which had given them an evolutionary advantage.
Grasshopper Ecology: Many animal Many animals use sound to communicate, especially when it comes to wooing the opposite sex. To attract females, male grasshoppers rub their hind legs over a vein on their wings, producing a buzzing call that females use to locate and select their mates. Because grasshoppers have powerful jumping legs and wings. Most grasshoppers are strong fliers, and will make good use of their wings to escape predators.
Grasshopper Human Impact:
In many areas of Africa, Asia, and America both locusts and grasshoppers are a regular ingredient of the local diet. They also can cause tremendous damage to crops and could completely defoliate a landscape, leaving farmers without crops and people without food.