Key to the Atlantic Species of Microgobius
From Birdsong 1981
1a. Three pores in preopercle sensory canal;
soft dorsal fin with more
than 17 elements; anal fin with more than 18 elements;
lateral scale
rows greater than 65 .............................................................................
2
1b. Two pores in preopercle sensory canal;
soft dorsal fin usually with
17 or fewer elements; anal fin with 18 or fewer elements; lateral
scale
rows fewer than 65 ..................................................................................3
2a. Soft dorsal-fin elements 20-21; anal fin
elements 21 (occasionally 20);
lateral scale rows about 77-90; scales mostly cycloid; females
with pale
bar edged in black on body above pectoral fin ................................
signatus
2b. Soft dorsal fin elements 18-19; anal fin
elements 19 (occasionally 20);
lateral scale rows about 68-78; scales mostly ctenoid; no dark
markings
on body in either sex ..................................................................
microlepis
3a. A fleshy median crest present on nape;
a prominent dark spot on
body below spinous dorsal fin origin; caudal fin usually greater
than
40% of SL ........................................................................................
meeki
3b. Fleshy median crest absent or poorly developed
on nape; body with
no dark spot below spinous dorsal origin or with many dark spots;
caudal fin usually less than 40% of SL ...................................................4
4a. Scales mostly ctenoid; about 4 enlarged
caninoid teeth in outer row
of each dentary; interorbital width broad (about 4% of SL);
a broad
yellow stripe on side with 2 narrow yellow stripes above .....................
carri
4b. Scales mostly cycloid; about 8 enlarged
caninoid teeth in outer row
of each dentary; interorbital width narrow (less than 3% of
SL); no yellow
stripe on body ...............................................................................................
5
5a. Three pores in lateral cephalic sensory
canal; body with numerous
dark blotches; mouth of males greatly enlarged (greater than
15% of SL
in males larger than 25 mm) ................................................................
gulosus
5b. Two pores in lateral cephalic sensory canal;
body without dark spots;
mouth of males little enlarged (less than 15% of SL in males)
...... thalassinus
