Invertebrates

Latest observations of Invertebrates

iSpot INVERTEBRATES

The term "Invertebrates" covers a very broad group, including insects, worms, molluscs, arachnids, and many others, that tends to get lumped together under the heading 'bugs' or 'mini-beasts'. The vast majority of all animal species are invertebrates, and estimates of the number of species in southern Africa exceed 150,000 or more.

Within this huge number of species there are animals that specialise in almost every conceivable habitat, and their life-cycles are correspondingly varied. Entire families, classes and even orders are often specialized in certain habitats or lifestyles.

Photography for identification

The characters needed for identification vary between the different groups, so the general advice is to try and get shots from various angles, including close-ups and more distant habitat shots for context. Size matters! If there is nothing in your photo to give a sense of scale you should measure or estimate the size and keep a note of that.

Insects

Insects are by far the most successful group on earth in terms of species. Several groups actually have two distinct life forms, a larval stage devoted to eating and growing, and an image stage devoted to dispersal and reproduction; the egg and pupae stages between these can act as ôpauseö phases to allow survival under unfavourable conditions. The following orders have more than 100 species in southern Africa.

  • Fleas (Siphonaptera): 100 species.
  • Dragonflies and Damselflies (Odonata): 160 species.
  • Mantids (Mantodea): 185 species.
  • Caddisflies (Trichoptera): 195 species.
  • Termites (Isoptera): 200 species.
  • Thrips (Thysanoptera): 230 species.
  • Cockroaches (Blattodea): 240 species. Some 20 genera are endemic. In Fynbos 3 genera and 25 species are endemic, and in Succulent Karoo 3 genera and 20 species are endemic.
  • Lacewings (Neuroptera): 385 species.
  • Crickets and Grasshoppers (Orthoptera): about 900 species, with many endemics.
  • Lice (Phthiraptera): about 1150 species, many highly specialized to species of mammals and birds.
  • Bugs (Hemiptera): over 2000 species of Stinkbugs (Heteroptera) and over 1400 species of Hopperbugs (Homoptera). Some 13 families have more than 100 species, including Capsids, Lacebugs, Assassinbugs, Twigwilters, Seedbugs, Stinkbugs, Cicadas, Treehoppers, Leafhoppers, Aphids, Armourscales, Softscales and Mealybugs.
  • Flies (Diptera): over 4800 species. Some 15 families have more than 100 species, including Craneflies, Midges, Mosquitoes, Soldierflies, Horseflies, Mydasflies, Robberflies, Beeflies (940 species), Danceflies, Hoverflies, Leafmining Flies, Houseflies, Bluebottleflies, Fleshflies and Tachanidflies. See Manual of Afrotropical Diptera
  • Moths and Butterflies (Lepidoptera): over 5900 species. Some 14 families have more than 100 species, including Goatmoths, Clothesmoths, Burnetmoths, Slugmoths, Pearlmoths, Lappetmoths, Hawkmoths, Pussmoths, Tigermoths, Tussockmoths, Skippers and Blues, with two having over 1000 species: Loopermoths (1000) and Owletmoths (1700). To help identify moths try the African Moth database
  • Wasps, Bees and Ants (Hymnoptera): over 6000 species. Some 12 families have more than 100 species, including Ichneumonid Wasps, Braconid Wasps, Aphelinid Wasps, Encyrtid Wasps, Dryinid Wasps, Cuckoowasps, Velvetwasps, Spiderwasps, Potterwasps, Sandwasps (730 species), Carpenterbees and Ants (600). Namaqualand (Succulent Karoo ) is known as a centre of speciation for solitary bees. To help identify ants try the Ants of Africa pages and Ants of the World, and wasps and bees Wasps, bees
  • Beetles (Coleoptera): over 18 000 species. Some 23 families have more than 100 species , including Tigerbeetles, Waterbeetles, Antstonebeetles, Rovebeetles, Mitebeetles, Jewelbeetles, Throscid Beetles, Clickbeetles, Chequerbeetles, Softwing Flowerbeetles, Pollenbeetles, Ladybirdbeetles, Hairy Ladybirdbeetles, Blisterbeetles, Longhornbeetles, Peaweevils, Fungusweevils, Domeweevils, , with five having over 1000 species: Leafbeetles (1300), Groundbeetles (1400), Scarabbeetles (1950), Snoutweevils (2500), and Toktokkiebeetles (3100). Namaqualand (Succulent Karoo ) is known as a centre of radiation for Monkey Beetles (Scarabs), and the Namib for Toktokkiebeetles.

Crustaceans

Crustaceans have achieved in the seas what Insects did on land: at sea they are by far the most successful group in terms of species. Moulting is required to grow and the entire outer skeleton is shed: this is a vulnerable phase as until the new skeleton has hardened the animals are soft and helpless. Most species have planktonic larvae, some with over 13 larval stages. The following orders are significant in southern Africa (other groups include Seedshrimps, Copepods, Leafshrimps, Cumacea shrimps, Tanaidshrimps, Mantidshrimps, Opossumshrimps, Krill, Cleanershrimps and Sandprawns).

  • Rocklobsters (Macrura): 5 species, including Crayfish (or West Coast Rocklobster).
  • Hermitcrabs (Anomura): 45 species.
  • Barnacles (Cirripedia): ?? species.
  • Isopods (Isopoda): 270 species: these are flattened top to bottom.
  • Amphipods (Amphipoda): 300 species: these are flattened side to side.
  • Truecrabs (Brachyura): 300 species.

Chelicerates

There are about 3600 species of Spiders in 64 families in southern Africa. Scorpions number 130 species in 4 families. Their relatives Solifuges, Whipscorpions, Harvestmen, Ticks and Mites are also diverse. All these require special techniques to study in detail (e.g. scorpions glow in UV light), but are well worth the effort, if only to know if what has stung or bitten you is venomous (less than 10 species) or not: please be careful!

Molluscs

Molluscs are characterized by having a head and foot, the former with a calcium rasp, and the latter usually with a lime shell. There are seven classes, although Lampshells and Tuskshells are not well known.

  • Chitons (Polyplacophora): 26 species.
  • Muscles and Clams (Bivalva): ?? species.
  • Abalones, Limpets, Winkels, Chitons, Turbanshells, Cowries, Whelks, and Coneshells (Gastropoda): ?? species.
  • Octopuses, Squids and Cuttlefish (Cephalopoda): ?? species.
  • Seahares (Opisthobranchia): 300 species. These predators have no shells.

Land Molluscs are the familiar snails and slugs. We have about 650 species in southern Africa. These can be grouped into 3 bioregions û the Cape (associated with the Cape Floral Kingdom or Fynbos) which although not very rich, has a very high endemism and ancient Gondwana roots; the Arid Northwest with specialized desert snails; and, the species-rich Eastern zone. Within the latter region a group associated with the Maputoland/Pondoland centre of plant endemism can be discerned. Over half the fauna comprises Tropical African groups, of which the Agate, Bark, Hunter, Awl and Tail Snails dominate. The largest genus is Gulelle (with 125 species, mostly small û 4mm), and as suggested by their common name, Hunter Snails, they are carnivorous. Forests (Afrotemperate Forest and Eastern Subtropical Forest) are richest for snails (up to 30 species in any one spot), as is densely wooded Savanna, but Grassland is poor in species.

Echinoderms

Echinoderms are exclusively marine: their plumbing, which includes the hydraulics of the tubefeet, precludes terrestrial or freshwater existence. They comprise five classes, namely Brittlestars (120 species), Featherstars (17), Seacucumbers (?), Seaurchins (60) and Starfish (90).

Bristleworms (Polychaeta)

Bristleworms are far more common than most people realise: over 800 species are known from southern Africa shores. Some species cannot easily be identified from photographs û for example the Nereidae require a dissection of the mouthparts to extrude the pharynx (gullet) and display the paragnaths (tiny teeth below the jaw) to identify the genera and species. Nevertheless, there are many spectacular forms well worth exploring further (e.g. Bambooworms, Beadworms, Bloodworms, Clubworms, Fanworms, Fireworms, Iridescentworms, Tangleworms, Tubeworms and Wonderworms, to name but a few).

Useful links in the UK: help us by suggesting local links û please contact us if you have any.

bees, wasps and ants

beetles

butterflies and moths

dragonflies and damselflies

flies

grasshoppers and crickets

true bugs

other insects

other invertebrates

There are local invertebrate groups in many counties, to find out about yours try contacting your local Environmental Records Centre or Wildlife Trust. See also Nature Societies Online from the Natural History Museum.

Marine invertebrates

  • Marine invertebrates are recorded as part of the MarLIN project, which has online identification resources and recording forms.
  • The Marine Biological Association promotes research into marine life, publishes a range of journals and other resources, and runs events and courses.
  • Seasearch works with volunteer divers to record marine habitats, as well as running projects on particular species.
  • The Marine Conservation Society promotes the conservation of marine habitats and species.

Invertebrates group links

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