...More Details on The Characteristics!...

Differences between Invertebrate and vertebrate by Vania Almira

Definition:

Invertebrates

invertebrates are the most abundant organisms on earth. They occupy almost all habitats, they can be found crawling, flying, swimming or floating. Invertebrates are the animals without backbone. These animals do not have internal skeleton made of bone. They play a vital role in the earth's ecosystem. About 99 per cent of the known organisms are invertebrates. Out of the planets estimated 15-30 million species about 90% of the animals are invertebrates. These come in may shapes and sizes and provide services that are vital for our survival. The most common vertebrates include sponges, annelids, echinoderms, molluscs and arthropods. Arthropods includes insects, crustaceans and arachnids.

Animals of Invertebrates:

• Marine Invertebrates - There are a wide variety of interesting ocean animals that are invertebrates. These include sponges, corals, jellyfish, anemones, and starfish.
• Mollusks - Mollusks have a soft body that is covered by an outer layer called a mantle. Many mollusks live inside a shell, but not all of them. Some examples of mollusks include squid, snails, slugs, octopuses, and oysters.
• Crustaceans - Crustaceans are a type of arthropod, meaning that they have jointed legs. They also have an exoskeleton (their bones are on the outside like a shell). Some examples of crustaceans are crabs, lobster, shrimp, and barnacles.
• Worms - The term "worm" is not a scientific word, but is often used to refer to invertebrate animals that don't have legs. Worms may live in the soil, in the water, or even inside other animals as parasites. Some examples include the tapeworm, the leech, and the earthworm.
• Insects - Insects are part of the Earth's largest animal phylum, the arthropods. There are over 1 million species of insects including such animals as the grasshopper, dragonfly, yellow jacket, butterfly, and praying mantis.
• Spiders, Centipedes and Scorpions - These animals are all part of the arthropod phylum. Spiders and scorpions are arachnids because they have eight legs. Centipedes and millipedes are myriapods and have lots of legs. Some myriapods have as many as 750 legs. Some example species include the tarantula and black widow, which are both spiders.

Vertebrates:

Vertebrates are animals that have a backbone or spinal column, also called vertebrae. These animals include fish, birds, mammals, amphibians, and reptiles. Vertebrates are classified by the chordate subphylum vertebrata. Invertebrates are any other animal that is classified outside of that class. There are currently around 65,000 known species of vertebrate animals. This sounds like a lot, but vertebrates are only around 3% of all the animals on Earth. Most of the animal species are invertebrates.

Animals of Vertebrates:

• Fish - Fish are animals that live in the water. They have gills that allow them to breathe under water. Different species of fish may live in fresh water or salt water. Some examples of fish include the brook trout, the great white shark, lionfish, and the swordfish.
• Birds - Birds are animals that have feathers, wings, and lay eggs. Many, but not all, birds can fly. Some examples of bird species include the bald eagle, the cardinal, the flamingo, ostriches, and the red-tailed hawk.
• Mammals - Mammals are warm-blooded animals that nurse their young with milk and have fur or hair. Some examples of mammals include humans, dolphins, giraffes, horses, and spotted hyenas.
• Amphibians - Amphibians are cold-blooded animals. They start out their lives living in the water with gills just like fish. Later they develop lungs and can move to dry land. Amphibians include frogs, toads, newts, and salamanders.
• Reptiles - Reptiles are cold-blooded animals which lay eggs. Their skin is covered with hard and dry scales. Reptile species include alligators, crocodiles, snakes, lizards, and turtles.

Differences:

• Vertebrates have a backbone with a spinal cord, whereas invertebrates do not.

• The diversity is exceptionally high among the invertebrates compared to vertebrates.

• Vertebrates are always bilaterally symmetrical, while invertebrates could show either bilateral or radial symmetry.

• Vertebrates are usually large-bodied and move fast compared to invertebrates.

• Vertebrates have a closed blood system, a well-developed brain, either gills or lungs for respiration, and a complex and sophisticated nervous system, whereas those are primitive in invertebrates. Therefore, it concerns that vertebrates have many specializations to extract the best out of the environment compared to invertebrates.

From those differences above, someone could has an additional infromation that invertebrates are more adaptive due to their simplicity, whereas vertebrates do not have a good adaptability in comparison because of the specialization. However, I would like to quote a popular quote to finish that in evolution specialization paralyses and ultra specialization kills the viability of taxons.

Characteristics of Invertebrates

• The main characteristic that separates invertebrates from other organisms is the absence of the spinal column and backbone.
• They are multicelluar organisms, they completely lack cell walls.
• They are devoid hard bony endoskeleton.
• Due to the lack of complex skeletal systems, some invertebrates tend to be slow and small in nature.
• Due to the lack of the backbone and complex nervous system the invertebrates cannot occupy mulitple environments, though they are found in the harshest of the environments.
• Invertebrates live all over the world in various habitats.
• Body is divided into three parts - head, thorax and the abdomen.
• They do not have lungs for respiration.
• Respiration is through skin.
• Some invertebrate groups possess a hard, chitinous exoskeleton.
• Most of them have tissues, that are specific organization of cells.
• Most of them reproduce sexually by the fusion of the male and female gametes.
• Few invertebrates like the sponges are sedentary, but most of the organisms are motile.
• Most invertebrates are organized with symmetric body organization.
• They can not make their own food, are heterotrophs.

( Post by Vania Almira )

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CLASSIFY IT!

CLASSIFICATION OF VERTEBRATES

1. Class Cyclostomata

The living species in this class are all ectoparasites on some fishes. They have elongated body, They bear through gills in which they respire. The mouth of the cyclostomes sucks circularly without jaws. They do not have body scales and fins, and of course they have vertebrae. They're marines organisms but they migrate to freshwater for spawning. They metamorphose, after metamorphosis their larvae returns to the ocean.

E.g. Petromyzon (Lamprey), and Myxine (Hagfish).

2. Class Chondrichthyes

These organisms are marine and have streamlined body. And the endoskeleton is cartilaginous. Their mouth is located ventrally and the notochord is present throughout life. The gills are seperated. Their skin contains minute placoid scales, these scales are modified as teeth and they have powerful jaws. They're also predators.

E.g. Various types of sharks, Scolidon, Pristis, Trygon.

3. Class Osteichthyes

These class has both marine species and fresh water species, with bony endoskeletons. Their body is streamlined. Mouth is terminal in position. The gills are covered with operculum on each side and are in four pairs.The skin is covered by ctenoid/cycloid scales. Air bladder is present, it regulates buoyancy. Two-chambered heart is present, with one auricle and one ventricle. They are poikilothermic animals. The sexes are separate, fertilization takes place externally.

E.g. Hippocampus, Claritas

4. Class Amphibia

The name Amphibia indicates - from Greek, Amphi meaning dual and bios meaning life.  Ampibians can live both in aquatic and terrestrial habitats. These animals have two pairs of limbs. Body is divisible into head and trunk and tail is present in some animals. The skin of these animals are scaleless and moist. The eyes have eyelids, and the ears are represented by a tympanum. Cloaca is a opening to the exterior, it is a common chamber for the alimentary canal, urinary and reproductive tracts.Gills, lungs and skin aids in respiration. Heart is three-chambered. They are cold-blooded animals. Sexes are separate, fertilization is external. They are oviparous animals and development is indirect.

E.g. frogs, toad, salamander

5. Class Reptilia

In Latin repere or reptum means to creep or crawl, hence, the class name refers to locomotion that is of creeping or crawling mode.

These animals are mostly terrestrial and their body is covered dry and cornified skin, epidermal scales or scutes. External ear opening is absent, tympanum represents the ear. Limbs, if present are of two pairs. Usually heart is three-chambered, but is four chambered in crocodiles. They are poilkilothermic animals. Some animals like the snake and the lizards shed their skin. Sexes are separate, internal fertilization takes place. They are oviparous and development is direct.

E.g. Turtle, Crocodile

6. Class Aves

Most of the members can fly, except the flightless birds. The characteristic feature of birds is the presence of feathers. The forelimbs are modified as wings. The hind limbs are modified for walking, swimming or clasping and generally have scales. The skin is dry and does not have glands, except a oil gland at the base of the tail. Endoskeleton is bony, and the bones are hollow with air cavities known as pneumatic bones. Heart is four-chambered completely. They are warm-blooded animals. Lungs are the organs of respiration. Sexes are separate, fertilization is internal.

E.g. Pigeon, parrot, and any kinds of birds

7. Class Mammals

Mammals are present in almost all habitats - polar ice caps, deserts, mountains, forests, and grasslands. The unique characteristic of the class mammalia is the presence of milk producing glands (mammary glands), by which the young ones are nourished. The limbs are of two pairs. The skin is covered with hairs. External ear 'pinna' is present. Heart is four-chambered and they are homeothermic animals. Respiration is through lungs. Sexes are separate and fertilization is internal. They viviparous animals, with direct development. Humans are included as Mammals.

E.g. Cats, Dogs, Kangaroo, Rabbit, etc

CLASSIFICATION FOR INVERTEBRATES

( Post by Aurelia Nadine )

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Invertebrates Or Vertebrates?

There are two basic groups of higher animals. They are vertebrates and invertebrates. While both have advanced through the processes of evolution, there is one fundamental difference. Invertebrates do not have backbones. Both groups are in the Kingdom Animalia, but their bodies are organized differently. What makes invertebrates different? All invertebrates share common traits. At the bottom of the invertebrate world are the sponges. Sometimes they don't fit in but they are still part of the group. Here's the nice and neat little list.

1. They’re multicellular. Means that the cells are working together for survival, because all of the cells have their own duties and responsibilities
2. No backbone. That’s the whole point of invertebrate, no vertebrae
3. No cell walls. When we talk about plants, we always mentioned cell walls, different with invertebrates. Being an animal means that having cell walls
4. Most of them reproduce sexually (not asexually)
5. That means two gametes combine to form a new organism. Those gametes come from separate organisms (male and female).

6. Invertebrates can't make their own food. Scientists use the word heterotrophic. Heterotrophs feed off other things to get their energy. Plants are autotrophic. They make their own food. Being heterotrophic is one of the main characteristics of being an animal. We eat things, whether it is plants or other animals. That's just the way the world works.

Vertebrates are the most advanced organisms on earth. Just like their name, they have vertebrae or backbone, unlike invertebrates. They have a series of nerves along their back or dorsal side. Vertebrae or the backbone works to support the nerves in the back part of their body, the nerves can’t just sit there, the y need support and protection. Fifty thousand species might seem like a lot. Compared to the invertebrates, there are not that many species of vertebrates. You might be asking why. One reason is that vertebrates are usually larger than invertebrates. They need more space. Another reason is that, even though they are more advanced, there are many limitations on the environments that are available to them. Vertebrates are smart, they have brains, of course. Just like any other living things in this world. But vertebrates are more intelligent than invertebrates because they have advanced nervous system, just like humans, we have advanced nervous system used to think.

General characteristics of the sub-phylum Vertebrata are as follows, although some are already mentioned above, here’s the list:

• Vertebrates have a well developed brain.
• Brain is set inside a bony box, known as cranium.
• Notochord is present in all chordates during sometime of development, it is formed on the dorsal side of the primitive gut in the early embryo stage.
• Most vertebrates possess guts with a non-terminal anus.

• The mouth cavity and the oesophagus is connected by the pharyngeal gill slits to a muscular tube pharynx, which opens to the exterior.
• They possess a dorsal hollow nerve tube at some stage of their life.
• Possess a dorsal cartilaginous nerve rod known as the notochord.
• At some stage of their life possess gill slits in the pharyngeal region.
• Have partially open circulatory system.
• Possess two pairs of appendages.
• The endoskeleton is made of cartilage or bone.
• The first vertebrates were jawless fishes with single caudal fin.
• The advancement of vertebrates with a hinged jaw which opened new food options and jawed fishes became the dominant creatures in the sea.
• All vertebrates have a heart and closed circulatory system.
• Reproduction is normally sexual.
• Feed on variety of organic materials.
• Unisexual animals, have one pair of gonads.

( Post by Aurelia Nadine )

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