Population treatment


Monitoring of Goodeid species

The figures entered into the species databank are evaluated after every update and the relative abundance of each species calculated following a system which takes into account the estimated total of adult specimens being maintained by the GWG. These results are considered alongside conservation status in the wild, currently based on John Lyons’ April 2011 figures, and total number of active breeders in order to decide which species/population should be targeted for intensive breeding efforts.

In order to maintain simplicity we categorise species as follows:

Wild populations: 

10 points: extinct in wild
8 points: critically endangered
6 points: endangered
4 points: vulnerable
2 points: least concern

Captive populations: 

5 points: less than 50 adults
4 points: between 50 and 150
3 points: between 150 and 300
2 points: between 300 and 1.000
1 point: more than 1.000 adults

Number of breeders:

1 point: 0-1 breeder
0.8 points: 2-4 breeders
0.6 points: 5-9 breeders
0.4 points: 10-19 breeders
0.2 points: 20 < breeders

The points total for a given species/population can then be used as a rough index relating to its overall conservation status; the higher the total, the greater concern it is to the GWG.

This index currently ranges from 3.2 - 16 points, and we consider species to fall within one of three categories based on score:

> 12 points: target species - first order (TS1)
6 - 12 points: target species - second order (TS2)
< 6 points:  not currently a target species


Captive Population Management

A standardised ‘voucher’ including details of origin and captive history is attached to any surplus stock distributed by GWG members in order to reduce the likelihood of hybridisation between populations as well as provide information to new breeders. There are essentially no restrictions regarding circulation of stock except in the case of TS1 species when there exist less than 5 breeders and 300 documented adults. These special cases are allocated to our most experienced/productive breeders in order to maximise potential – a measure we regard as essential in order to preserve captive populations. Breeders are selected based on proven past experience plus physical capacity for productive long-term maintenance.