Grass Pickerel - BIO 210 Species Study
Development
Esox americanus vermiculatus species
follows a strict development pattern beginning with mature,
fertilized eggs hatching into mobile fry and then the mobile fry
growing into a fingerling from which growth progresses leading
to the development of an adult Grass Pickerel. (Kleinert and
Mraz, 1966) After fertilization occurs, egg maturation takes
place for roughly ten days, at which point, the mature egg
evolves from egg form into a mobile fry. (Kleinert and Mraz,
1966) A fry is simply a newly hatched egg for this species. This
newly hatched egg already shows characteristics of E.
americanus vermiculatus due to its visible pigment-free
lateral lines running from snout to tail. Another unique
characteristic of this fry is its black eye pigmentation. (Kleinert
and Mraz, 1966) Growth occurs in the fry stage and soon the fry
becomes the determinate size of a fingerling; the approximate
size of a human finger. Fingerlings visibly portray an even more
accentuated pigment-free region running laterally along both
sides of the body. (Kleinert and Mraz, 1966) Once the fingerling
stage has been reached, growth occurs into a mature, adult Grass
Pickerel in which a darker complexion of green stripes has
become evident and accentuating the pigment-free lateral line
even more. (Cain et. al, 2008)
Once a fingerling reaches 9.0 mm in length, a
mature mouth on the snout is prevalent in preparation for transformation
to the feeding stage of the fingerling. (Kleinert and Mraz, 1966) A true
feeding stage is prevalent as early as two weeks post fertilization and
as late as five weeks post fertilization at which point the fingerling
has reached 10 mm in length. (Kleinert and Mraz, 1966) Appearance of
adult features becomes evident at 45 mm in length at which point the
darker green complexion of continuous stripes separated by a
pigment-free lateral line becomes visible. (Kleinert and Mraz, 1966)
Maximum growth occurs around 350 mm, making this
member of the pike family the smallest. (Weinman and Lauer, 2007) After
two years, both male and female Grass Pickerel reach sexual maturation
and have roughly five more years of life considering their life
expectancy does not exceed seven years of age. (Fisheries and Oceans
Canada, 2012)
Next, we tackle the diverse diet of the Grass Pickerel and how this diet is altered and diversified in congruency with the development discussed on this page. Click here to continue to our nutrition page.