1 Why is species identification important?

As highlighted in the Introduction, the accurate identification of organisms is important when measuring the biodiversity of an area. It is also a prerequisite when attempting to find out more about the ecology of a species. And without accurate identification it is impossible to determine how many species exist in a given area.

Identifying organisms is, however, a task fraught with difficulties. A single type of organism may be misidentified as several different species. For example, if the males and females look very different or if the species is very variable, such as the harlequin ladybird (Harmonia axyridis). In some cases, the larval stages of a species may also be mistakenly identified as a different species. (Refer back to Week 2 for more information on what constitutes a species.)

Alternatively, several different types of organism may be lumped together as a single species. This has happened many times, especially with ‘cryptic’ species such as the soprano pipistrelle bat (Pipistrellus pygmaeus). This wasn’t distinguished as a separate species from the morphologically very similar brown pipistrelle (Pipistrellus pipistrellus) until 1999, initially based on differences in echolocation frequencies. There may be large numbers of cryptic species in certain groups of organisms such as fungi.

Over the course of this week you will examine photographs and videos that demonstrate, through examples, common situations in which simply assuming individual species that look somewhat different are actually different could give a substantial over- or underestimate of the number of species.