| Daddy long legs |
Tipulidae |
| Daddy long legs spider |
Pholcidae |
| Damselfly |
Zygoptera |
| Dance fly |
Empididae |
| Darwinism |
The view of evolution as expressed by Charles Darwin, i.e. that evolution occurs by natural selection acting on random variation found in organisms, and resulting in the survival of the fittest. |
| Death rate |
Mortality. The number/percentage of deaths in a population over a given time. |
| Decapods |
The group of crustaceans which includes crabs, lobsters, prawns and shrimps. |
| Definitive host |
The host in which sexual reproduction takes place. Or in cases where there is no sexual reproduction, the host in which the parasite/symbiont becomes mature and reproduces. |
| Demography |
the study of statistics relating to births and deaths in populations |
| Demospongiae |
Class of sponges (Porifera) that contains the bath sponge. |
| Density |
the number of individuals per
unit area |
| Denticle |
a tooth-like process on the cuticle |
| Depauperate |
Impoverished; having few species. |
| Deposit feeder |
an animal that feeds on particles of organic matter that drift downwards through the water to settle on the bottom. |
| Dermaptera |
earwig |
| Dermestidae |
carpet beetle, skin beetle |
| Desiccation |
the removal of water, the process of drying |
| Detritus |
dead organic matter |
| Detrivore |
an animal that eats dead plant and animal matter |
| Dextral |
rotating to the right, as in snail shells. The opposite is sinistral. |
| Diadromous |
Migrating between fresh and sea water |
| Dichotomy |
a division into 2 parts or categories |
| Dictyoptera |
The order of Insects containing the cockroaches and mantids. Some authorities now separate these into 2 orders. |
| Diapause |
A period of arrested development found mainly in insects, in which physiological activity is very low, and the animal is highly resistant to unfavourable external conditions. |
| Diet selection |
An animal will usually rank
items in terms of profitability. Most profitable are those with a high size
and/or quality : search, handling time ratio |
| Diffusion |
The spontaneous tendency of a substance to move down its concentration gradient from a more concentrated to a less concentrated area |
| Digestion |
the process of breaking down food into molecules small enough for the body to absorb |
| Dimorphism |
The existence within a species of 2 distinct body forms differing in colour, or sex, or size, etc. |
| Diploid |
Having a double set of chromosomes |
| Diplopoda |
Millipedes |
| Diptera |
true flies |
| Disjunct |
Distinctly separate. Used when describing populations which are so separated from each other as to prohibit interbreeding, and therefore gene flow. |
| Dispersal |
The spread outwards of organisms from their point of origin or release. The extension of range of a population or species. |
| Display |
A behaviour or signal which conveys information, e.g. wolf spiders signalling with their palps before mating. |
| Disruptive colouration |
colouring making it difficult for a predator to recognise the whole animal - as seen in many butterflies and moths. |
| Distal |
at the furthest end from the attachment of an appendage - opposite of proximal |
| Diurnal |
active during the day |
| Diversity |
The number of species in a community, also known as species richness. The measure of the number of species and their relative abundance in a community. |
| DNA |
Deoxyribonucleic acid |
| Dominance hierarchy |
a social ranking, formed through agonistic behaviour, in which individuals are associated with each other so that some have greater access to resources than others. |
| Dorsal |
of or belonging to the back |
| Dragonfly |
Odonata, ansioptera |
| Drone |
the male bee hatched from an unfertilized egg |
| Drosophilidae |
fruit fly, vinegar fly |
| Dung beetle |
a beetle in the Scarabaeidae family. |
| Dytiscidae |
A family of water beetles. Both larvae and adults are carnivorous, the adults are usually strong swimmers. |
| Earthworm |
A worm in the Oligochaeta Class of the Phylum Annelida. |
| Earwig |
An insect in the Dermaptera Order |
| Ecdysis |
moulting of cuticle to increase body size, e.g. in crustaceans. Normally it is hormonally controlled. |
| Ecdysone |
The hormone in insects and crustaceans that stimulates ecdysis. |
| Echinoderms |
A phylum of animals including starfish, brittle stars, sea urchins, etc. Echinoderm - spiny skin. |
| Echinoidea |
sea urchins, heart urchins, sand dollars. |
| Echiura |
spoon worms |
| Ecological isolation |
the prevention of interbreeding between population in the same area because of ecological barriers |
| Ecology |
the study of how organisms interact with their environment |
| Ecosystem |
a collection of species living in the same habitat together with their physical surroundings |
| Ectotherms |
Animals that must use environmental energy and behavioural adaptations to regulate their body temperature. Cold-blooded animals, e.g. most invertebrates, reptiles and amphibians |
| Ectoparasite |
A parasite that lives on the outside of its host. Opposite is endoparasite. |
| Elateridae |
Click beetles, skipjack beetles |
| Elbowed antennae |
aka geniculate antennae; antennae bent at an angle near the middle, as seen in bumblebees |
| Elytra |
the hardened fore wings of beetles. They serve as covers for the hind wings |
| Embioptera |
Webspinners |
| Emigration |
the movement of an individual or a group out of a population or area. |
| Empididae |
dance flies |
| Endemic |
A species which is encountered only in a given area or region, e.g. Primula scotica is endemic to Scotland. |
| Endoparasite |
A parasite that lives within the body of its host. Opposite is ecto parasite. |
| Endopterygote |
An insect in which the wing buds develop internally, e.g. beetles |
| Endoskeleton |
a skeleton formed within the body - like the human skeleton. Opposite is exoskeleton. |
| Endotherms |
Animals that use metabolic energy to raise their body temperature, e.g. bumblebees, humans. |
| Energy flow |
The passage of energy through an organism, population or system; the passage of energy through a food chain or food web. |
| Epigyne |
in spiders and other female arachnids, the external structure of the reproductive opening, seen only in mature females |
| Entomogamous |
of a flower pollinated by insects |
| Entomology |
the study of insects |
| Entomophaguos |
feeding on insects, insectivorous |
| Entomophilous |
pollinated by and/or dispersed by insects |
| Enzyme |
A protein that turns on vital functions in the cell; a chemical messenger or catalyst. |
| Ephemeroptera |
Mayflies |
| Epidaemic |
used of a disease which affects a high proportion of the population and spreads over a wide area. |
| Epidermis |
the outmost cellular body covering |
| Epithelial cells |
Cover external surfaces and line the digestive tract and connecting structures. They are often flat in shape. |
| Epoch |
A major interval of geological time. An event or time marking the beginning of a new phase of development. |
| Era |
A major interval of geological time, e.g. the Precambrian. |
| Erosion |
The wearing away or weathering of land surfaces, e.g. by water, wind etc. |
| Errant |
moving freely. Opposite is sedentary. |
| Essential element |
A chemical element which is essential to the life of the organism. |
| Ethnozoology |
The study of the uses of animals and animal products by the races of man. |
| Ethology |
the study of how animals behave in their natural environment |
| Eukaryote |
An organism with cells that have a discrete nucleus containing the genetic material. |
| Eumenidae |
A family of solitary wasps also known as the mason or potter wasps |
| Euryhaline |
able to tolerate a wide range of seawater concentrations |
| Eusocial |
Bees and wasps in a colony of adults of two or more generations, composed of an egg laying queen and her daughters. |
| Eutely |
A fixed number of cells or nuclei in mature adult forms, as in some rotifers, acanthocephalans and nematodes.. |
| Eutrophication |
Over enrichment of water with nutrients, resulting in a population explosion of organisms and a reduction of oxygen. |
| Eutrophy |
The pollination of certain flowers by specialised insects. |
| Eversible |
capable of being turned inside-out |
| Evolution |
All the changes that have transformed life from its beginnings to the diversity we see today. |
| Evolutionary biology |
The science of evolution, ecology, behaviour and systematics. |
| Excretion |
disposal of the nitrogen-containing waste products of metabolism |
| Exopterygote |
an insect in which the wing buds develop externally, enlarging at each nymphal instar, e.g. in bugs. |
| Exoskeleton |
The horny outer shell which encloses and protects the body and to which the muscles are attached, as found in insects. |
| Exotic |
Alien; non-native; foreign; an introduced species. |
| Extant |
Existing or living at the present time. Opposite of extinct. |
| External fertilisation |
in reproduction a form of fertilisation that takes place outside the female's body - often in water. |
| Extinct |
No longer in existence;no longer living. Opposite of extant. |
| Extinction |
The disappearance of species or taxa from a habitat or biota. |
| Extra-oral digestion |
Digestion that takes place outside the organism, by secretion of salivary enzymes onto the food, with the resulting liquid digestive products being sucked up, e. g. in house flies and spiders. |
| Exude |
To ooze out, diffuse out. |
| Exuvium |
The cast off exoskeleton left by an arthropod after moulting. Most easily seen on a plant infested with aphids where the skins lie on the soil and leaves, also on the webs of successful spiders as the grow, and also here is a photograph of a woodlouse with its exuvium. |
| Eyespots |
simple eyes found on some annelids and flatworms. They enable the animal to distinguish light and dark, but little else. |
