none |
normal (not striking) |
|
none |
tube-like |
|
|
no spines |
no spines |
no rows |
one dorso-ventral cluster or band |
melanophores on head + trunk |
no rows |
tail partly covered with melanophores |
melanophores on head + trunk |
pigmented |
pigmented |
with row of melanophores |
normal melanophores at fin base |
normal (i.e. small or absent) without melanophores |
Eyes not stalked; complex pigment pattern unique among Bathylagus species (including Leuroglossus spp.); voluminous rugose foregut; fewer pairs of ventrolateral gut melanophores (6-8) than in B. nigrigenys (8-10); dorsal and ventral pigment at notochord tip vs. only ventrally in B. nigrigenys; trunk series heavier and more regular than in B. nigrigenys; more total vertebrae than B. nigrigenys (43-47 vs. 41-45); only bathylagid without stalked eyes and pigment consisting of a linear series of small melanophores.
Pigmentation: linear series of small melanophores; initially a series of paired spots dorsolaterally to gut extending from pectoral fin base to terminal section, becoming embedded with development (6-8 pairs developing to 7-8 pairs); notochord tip (dorsal and ventral).
Flexion: series of melanophores develops along hypaxial region, and soon after a series develops along epaxial; more lateral spots are added; median finfold; increased head pigment.
Postflexion-transformation: hypaxial and epaxial series along entire body, then 2 or more per myomere.
Sequence of fin development: caudal, anal, dorsal, pectorals and pelvics. |