Teil C - Annex 
51 
Dragonets - Callionymidae 
Only the genus (Callionymus) occurs in the German EEZ. This includes the common drag- 
onet (Callionymus lyra), the spotted dragonet (C. maculatus) and the reticulated dragonet 
(C. reticulatus). Species differentiation is more difficult in females than in males. C. macu 
latus and C. reticulatus are relatively small, therefore a magnifying glass should be used 
for identification, in particular as the thorns of the front gill cover must be examined in de 
tail. In addition to the identification clues in Muusand Nielsen (1999), drawings of the front 
gill cover thorns should be consulted, e. g. in Louisy (2002) and Fricke (1986). 
Gobies - Gobiidae 
Four species are considered established in the German EEZ: the common goby (Poma- 
toschistus microps), the painted goby (P. pictus), the sand goby (P minutus) and Loz 
ano’s goby (P lozanoi). The latter two species belong to the P minutus complex. Exact 
species identification is often difficult under field conditions. Flowever, safe identifica 
tion of P microps and P pictus is possible in the laboratory by using a stereo micro 
scope (binocular) and consulting Miller (1986). Flamerlynck (1990) should be consulted 
for differentiating the species P minutus and P lozanoi. To ensure the correctness of 
classification results, a random sample of classified material should be sent to experts 
for verification. In the event of large catches of gobies, the species classification of all 
individuals at sea can be very time-consuming. In such cases, the species classification 
should take place by representative sub-samples in the laboratory and subsequent 
extrapolation to the total catch. As the case may be, voucher specimen should be kept 
for the voucher collection. 
Determination of length distribution 
Length distribution must be recorded for all fish taxa. Length is defined as total length, meas 
ured between tip of the snout and tip of the tail. For herrings, sprats, sardines and anchovies, 
length is recorded in length classes of 0.5 cm, respectively rounded down to the next smallest 
0.5 cm step (“0.5 cm below”). All other fish taxa are measured in full 1 cm length classes, 
respectively rounded down to the next smallest full centimetre (“1 cm below”). 
It is recommended to measure and weigh all Elasmobranchii (sharks and rays) separately by 
gender. 
The exact representative length distribution is recorded for each catch category (species/ge 
nus). This can be the combined total catch of the catch category or a representative sub 
sample. A representative sub-sample consists of at least 75 fish; in all cases it must be as 
sessed whether the identified distribution corresponds to normal distribution. In cases where 
a true representative sub-sample cannot be chosen, the taxon in question must be separated 
into two or more size categories. 
• Example 1: A catch category consists of 999 fish measuring 18-26 cm in length and of one 
fish measuring 40 cm. A sub-sample of 100 fish would result in either no or 10 fish of 40 cm 
length for this catch category. The correct method is to exclude this one fish from the sam 
ple and to measure it as a separate sample in the size category 1. A sub-sample is taken 
from the remaining 999 fish (here: size category 2), measured and extrapolated to the 
number (or weight) of the size category 2.