Mutualism

 Mutualism 

Mutualism is an interspecific symbiotic relationship where both partners/ species are benefited from their interaction. 

• The term mutualism literally means "living together" and was coined by De Bary (1877).

Examples of Mutualism:

1] Termites and Trichonympha: Termites have a mutualistic relationship with endosymbiont -Trichonympha  (protozoa), a zooflagellate, that lives in the gut of termites and enables the termites to digest cellulose (the primary component of wood particles). These flagellates produce cellulase enzyme, which digests cellulose, producing by-products starch and glucose that both organisms can digest. With the help of their protist partners Trichonympha, then, the termites can eat wood. These  Trichonympha, a zooflagellate would die outside of the termite, and the termite would starve if it didn't have the endosymbionts, zooflagellate to help in wood digestion. By this, both partners are benefited from their interaction.

2] A mutualism between ants and the acacia trees, provides an excellent example of an obligate mutualism. 

•  The acacia provides a number of benefits to the ants, including shelter (hollow thorns), Ants feed on protein secreted by the beltian bodies present at the tip of leaflets of certain African Acacia trees. it also feeds on nectar secreted by nectarines found near the base of leaves. 
• In return,  The ant (Pseudomyrmex) provides several forms of protection to the acacia trees. It attacks and removes herbivorous insects, It also removes vines that might overgrow the acacia, and kills the growing shoots of nearby plants that might become competitors. It clears away leaf litter from near the plant, and since the acacia grows in a seasonally dry environment where it occasionally is threatened by fire, the ant's activities protect the tree from fire injury as easily.
  
  3] Bees and flowering plants have a mutualistic relationship: In this relation both species benefit. 

• Flowers benefit bees by providing them with all the food their colonies need, to survive. Bees feed on the nectar and pollen of flowers. Worker bees land on flowers and drink their nectar. The pollen sticks to the bee's hairy legs and body.   Plants cannot seek out mates the way animals do, they must rely on outside agents, called vectors, to move their genetic material from one plant to another. Such vectors include bees, certain birds, and wind.
• Flowering plants carry the male portion of their genetic material in their pollen. When bees fly from one flower to another, pollen is spread from plant to plant i.e pollination. If pollen from one flower is able to reach another flower of the same species, then that plant will be able to form seeds and reproduce.

                                           Scan to download

• Reference: Cook, Maria. "How Do Flowers & Bees Help Each Other?" sciencing.com, https://sciencing.com/do-flowers-bees-other-5796565.html. 13 February 2022.

Predation /B.Sc. I/ Animal Ecology

 Predation

Parasitism /B.Sc. I / Animal Ecology

Parasitism

• Ectoparasites live on the body surface of the host and do not cause disease in the host Examples to include ticks, fleas, leeches, and lice.
• Endoparasites live in the host’s body. Examples include Worms, Plasmodium, Bacteria, etc.

Symbiotic Associations /B.Sc.I / Animal Ecology

 Symbiotic Associations

• Symbiotic relationships are a special type of interaction between species or organisms. Sometimes beneficial, sometimes harmful, these relationships are essential to many organisms and ecosystems, and they provide a balance that can only be achieved by working together.

 

• Mutualism is a symbiotic relationship in which both species benefit.

 

• Commensalism is a symbiotic relationship in which one species benefits while the other species is not affected. Example: The relationship between cattle egrets and cattle.

 

• Parasitism is a symbiotic relationship in which one species (the parasite) benefits while the other species (the host) is harmed.

Commensalism

 The word "commensalism" is derived from the word "commensal", meaning "eating at the same table". The term was coined in 1876 by Belgian paleontologist and zoologist Pierre-Joseph van Beneden,

Commensalism is a type of relationship between two living organisms in which one organism benefits from the other without harming it. A commensal species benefits from another species by obtaining locomotion, shelter, food, or support from the host species, which (for the most part) neither benefits nor is harmed. The species that gains the benefit is called the commensal. The other species is termed the host species.

Examples of Commensalism

Remora fish have a disk on their heads that makes them able to attach to larger animals, such as sharks, mantas, and whales. When the larger animal feeds, the remora detaches itself to eat the extra food.

 

Remora are small fish that have a sucker-like disk on their heads that allows them to attach to other animals. Remora will use the sucker to attach to sharks, rays, turtles, whales, or other large marine animals. The remora benefits by getting to travel to new food and breeding areas without expending energy for travel and while being protected by the larger animal. The remora also benefits in another, somewhat grosser, way: its diet is made primarily of its host’s feces, so it has ample access to food while hitching a ride. Its carrier is unaffected because the sucker doesn’t harm or help it and the remora is small enough not to impede its movement or speed.

 

 

Figure : Commensalism cattle egrets on grazing cattle

·       Another typical example of commensalism is the cattle egrets (birds) that feed upon the insects stirred up by the feeding cattle. Cattle egrets get their food without disturbing the grazing cattle. ·       In these interactions, the cattle are unaffected, while the birds gain food.

 

 

 

Sea anemones and colorful clownfish also exhibit commensalism. Clownfish take shelter in the sea anemone to protect themselves from predators. In the adaptation process, clownfish develop a mucous coating around themselves, allowing them to take refuge in the sea anemone without affecting its stings. Also, clownfish feed upon the debris of the last meal of sea anemones, thus keeping them clean.

Domestic dogs, cats, and other animals appear to have started out with commensal relationships with humans.

Types of Commensalism (With Examples)

Inquilinism - In inquilinism, one organism uses another for permanent housing. An example is a bird that lives in a tree hole. Sometimes epiphytic plants growing on trees are considered iniquilism, while others might consider this to be a parasitic relationship because the epiphyte might weaken the tree or take nutrients that would otherwise go to the host. An example is a woodpecker drilling a cavity in a saguaro cactus to use as a nesting site. The woodpecker benefits; the cactus is unaffected.

 

Metabiosis - Metabiosis is a commensalism relationship in which one organism forms a habitat for another. An example is a hermit crab, which uses a shell from a dead gastropod for protection. Another example would be maggots living on a dead organism. Metabiosis is when an organism (often deceased) creates an environment for another organism, such as bacteria growing in the remains of a dead animal. The deceased animal, because it is dead, can’t be harmed or benefited, but the bacteria get a habitat and food source.

 

Phoresy - In phoresy, one animal attaches to another for transport. This type of commensalism is most often seen in arthropods, such as mites living on insects. Other examples include anemone attachment to hermit crab shells, pseudoscorpions living on mammals, and millipedes traveling on birds. Phoresy may be either obligate or facultative.

 

Microbiota - Microbiota is commensal organisms that form communities within a host organism. In this commensalism, the commensals grow inside the host to form a community. An example is the gut or skin microbiota in humans. Although there are conflicting views regarding classifying microbiota as a type of commensalism, recent studies have confirmed intestinal microbiota’s active and beneficial role in the healthy life of human beings. Historically, it is believed that the human gut provides shelter to the microbes without affecting the host human and is thus categorized as commensalism. However, recent studies have proven that gut microbiota is a source of essential amino acids and other nutrients required for the healthy life of humans. Thus, the classification of microbiota as a type of commensalism is under review by scientists

Competition

Animal Interactions/B.Sc. I/ Animal Ecology

 Animal Interactions

Animals interact with each other in multiple, complex patterns. though, we can make some general statements about these relations. This enables us to more understand the part that species play within their ecosystems and how individual species can favorably or negatively affect the species around them.

A resource, in ecological terms, is the thing ( like food, water, niche, sunlight, or prey) that's needed by an organism to perform a vital function such as growth or reproduction. A consumer is an organism that consumes a resource ( like predators, carnivores, or detritivores).

Species interactions can be grouped into four fundamental groups based on how the participating species are affected by the relation. 

They include

1. competitive interactions, 
2. consumer-resource interactions, 
3. detritivore-detritus interactions, and 
4. mutualistic interactions.

1. Competitive Interactions

• Competitive interactions are interactions involving two or more species that are competing for the same resource.
• In these interactions, both of the species involved are negatively affected. 
• Competitive interactions are in many cases indirect, such as when two species both consume the same resource but don't directly interact with each other. Rather, they affect each other by reducing the availability of resources. 
• An exemplification of this type of interaction might be observed between lions and hyenas. Since both species feed on the same prey, they negatively affect each other by reducing the quantity of that prey. 
• One species may have trouble hunting in an area where the other is already present.

2. Consumer-resource interactions

• Consumer-resource relations are relations in which individualities from one species consume individualities from another species. 
• Exemplifications of consumer-resource relations include Predator-prey relations/ interactions . These consumer-resource relations affect the species involved in different ways. Generally, this type of commerce has a positive impact on the consumer species and a negative impact on the resource species.
•  An illustration of consumer-resource interaction would be a Lion eating a zebra, or a zebra feeding on a grass. In the first illustration, the zebra is the resource, while in the alternate illustration it's the consumer.

3. Detritivore- detritus Interactions

• Detritivore- detritus interactions involve a species that consumes the debris ( dead or decaying organic matter) of another species. 
• The detritivore- detritus interaction is a positive interaction for the consumer species. It has no impact on the resource species since it's already dead.
•  Detritivores include small animals like as millipedes, slugs, woodlice, and sea cucumbers. 
• By cleaning up decomposing plant and animal matter, they play a major role in maintaining the healthiness of ecosystems.

4. Mutualistic Interactions

• Mutualistic interactions are interactions in which both species-- resource and consumer-- benefit from the interaction. 
• An example of this is the association between plants and pollinators. 
• Nearly three-quarters of flowering plants depend on animals to support them pollinating. 
• In exchange for this service, animals such as bees and butterflies are rewarded with food in the form of pollen or nectar. 
• The interaction is favorable for both species, plants, and animals.

References:

Klappenbach, Laura. "How Animals Interact in an Ecosystem." ThoughtCo, Sep. 6, 2021, thoughtco.com/how-do-species-interact-130924.