light organs |
normal (not striking) |
|
light organs |
spherical or gut loop |
pigmented |
pigmented |
no spines |
no spines |
ventral row |
one dorso-ventral cluster or band |
melanophores on trunk |
ventral row |
one dorso-ventral cluster or band |
melanophores on head + trunk |
unpigmented |
unpigmented |
with row of melanophores |
normal melanophores at fin base |
fin rays only without melanophores |
Anal fin origin slightly anterior to dorsal fin origin; no adipose fin; photophores form more suddenly than in G. elongatum; photophores present; characteristic loop in hindgut below prominent gas bladder; oval eye; pigment on ventral margin of tail, dorsally on gas bladder, and laterally on gut; no internal parhypural pigment.
Pigmentation:
Preflexion-flexion: series of 5-13 along ventral margin of tail; sparse ventrally on caudal finfold; over gas bladder after about 4 mm; pair along sides of gut just behind pectoral fin; present or absent on hindgut loop.
Postflexion-transformation: 17-18 in ventral tail series; double row forms along anal fin base; row along each side of gut from pectoral to hindgut; increasing over entire gut area during transformation; few on caudal peduncle near hypural edges; pair anteriorly on midbrain by about 6-7 mm; on hindbrain by about 11.5 mm; increases on head.
Sequence of fin development: caudal, anal, dorsal, pectorals and pelvics. |