Invertebrate Zoology: A Study Guide - T. A. Dauda 2014

The Significance of Invertebrate Animals in Natural Processes and Human Life

Invertebrates have colonised A wide variety of habitats on Earth: Water, soil, the Earth's surface, the air, and even other organisms as parasites or symbionts. The Role of animals in nature and human life is immense, and their Functions are extremely diverse.

The role of animals in the biogeochemical cycling of organic matter. Green plants produce organic matter, which is then consumed by herbivorous animals (such as caterpillar larvae, leaf beetles, and bark beetles). These, in turn, become prey for carnivores (ground beetles, ants, ladybirds, etc.). A number of other animals (such as dung beetles, carrion beetles, and Skin beetles) feed on animal excrement and remains.

Soil-dwelling animals (earthworms, centipedes, many insect larvae, certain mites, etc.) alongside microorganisms biochemically transform complex Organic compounds into Mineral Substances accessible to plants. Moreover, as they move through the soil, these animals displace soil layers, mixing organic compounds with mineral particles; by tunnelling, they improve soil aeration and water retention. Thus, soil is largely formed through the combined Impact of plant, animal, and microbial organisms, and its fertility depends heavily on the Abundance of these soil-dwelling communities.

Geological (rock-forming) activity of animals. The sediments of the World Ocean are largely formed by the accumulation of shells of single-celled organisms inhabiting the water Column (plankton) and the seabed (benthos). After death, their shells sink to the bottom, forming massive layers of ooze. The largest areas (29%) are covered by calcareous globigerina oozes, formed by the shells of foraminiferans of the genus Globigerina from the Class Sarcodina. Radiolarian oozes, formed by the microscopic skeletons of radiolarians (Sarcodina), account for 3.4%. Coral oozes, consisting of the breakdown products of coral reefs, cover approximately 3% of the seabed.

Many invertebrate animals (such as Annelids, Sponges, crustaceans, and Molluscs) play a significant role in The formation of marine deposits, particularly in shallow-water zones.

Using fossil animal remains to determine the relative age of rock strata. The Study of fossils helps us read the evolutionary and geological METABOLISM/13.html">History of the Earth's animal kingdom. Each historical period in our planet's history is characterised by the flourishing of specific animal groups. Consequently, their remains serve as index fossils, which make it possible to establish the chronological sequence of sedimentary deposits containing mineral resources, determine the relative age of strata, reconstruct past climatic changes, and map the distribution of land and sea in the distant geological past. Index fossils primarily comprise the remains of mass-form organisms: shelled Protozoans (foraminiferans, radiolarians), sponges, various Echinoderms, and others.

In recent decades, the study of microscopic remains of small organisms (foraminiferans, ostracods, crustaceans, etc.) and their mass accumulations has become increasingly important in the prospecting for mineral resources (such as oil and coal).

The role of animals in plant pollination. In Europe, 80% of angiosperms are insect-pollinated, about 19% are wind-pollinated, and roughly 1% rely on other Methods. The successful reproduction of most flowering plants, as well as the fruiting of all fruit trees, berry bushes, buckwheat, and clover, depends on effective pollinators. The most prominent pollinators include Hymenoptera (bees, bumblebees), Diptera (hoverflies, tachinid flies, soldier flies, etc.), butterflies, beetles, ants, and other flower-visiting insects that transfer pollen from one plant to another. Besides insects, other animals can also act as pollinators. For instance, many American hummingbirds transfer pollen that adheres to their feathers while the birds extract food (nectar or various small Arthropods) from flowers.

Damage caused by animals. First of all, it should be noted that there are no inherently "harmful" or "useful" animals in nature, although they may cause harm or bring benefits to humans. Animals frequently inflict substantial damage on agriculture and forestry. Furthermore, many species act as vectors, reservoirs, and causative agents of Human and Animal diseases.

According to estimates by international organisations, the economic damage caused by agricultural pests alone amounts to approximately 20% of the total global crop yield annually. The primary culprits are specific insect species, certain mites and molluscs, and various Roundworms.

During periods of mass outbreaks of forest pests, vast areas of coniferous forests in Germany, Poland, the Baltic states, and Belarus have been destroyed. By feeding on leaves or needles, pests severely weaken trees and reduce wood increment. Weakened trees become much more susceptible to bark beetles and other wood-boring pests, ultimately perishing. Rational forest management, proper sanitary felling, pest control, and population monitoring help prevent mass outbreaks over large areas.

A considerable number of animals are hazardous to humans. Examples include venomous jellyfish among Cnidarians; karakurt spiders, tarantulas, and scorpions among arachnids; centipedes; and stinging Hymenoptera, certain beetles, and other insects.

A number of human and animal diseases are caused by protozoans (such as malaria by the malaria parasite Plasmodium, African sleeping sickness by flagellated trypanosomes, and amoebic dysentery by the dysentery amoeba).

Many ticks, lice, and fleas serve as reservoirs and vectors for severe diseases, including tick-borne encephalitis, epidemic and relapsing typhus, and plague.

Parasitic worms (numbering around 10,000 species) infect numerous animals and humans.

Review and Self-Assessment Questions:

1. What natural processes involve animals?

2. What kinds of damage are caused by invertebrate animals?