Maternal investment evolves with larger body size and higher diversification rate in sharks and rays
Current Biology,
Journal Year:
2024,
Volume and Issue:
34(12), P. 2773 - 2781.e3
Published: June 1, 2024
Language: Английский
The origins and drivers of sexual size dimorphism in sharks
Ecology and Evolution,
Journal Year:
2024,
Volume and Issue:
14(3)
Published: March 1, 2024
Abstract
While
sexual
size
dimorphism
(SSD)
is
abundant
in
nature,
there
huge
variation
both
the
intensity
and
direction
of
SSD.
SSD
results
from
a
combination
selection
for
large
male
size,
fecundity
female
ecological
either.
In
most
vertebrates,
it
male–male
competition
that
primarily
underlies
this
study,
we
test
four
hypotheses
regarding
adaptive
value
sharks—considering
potential
each
fecundity,
sexual,
reproductive
mode
as
primary
driver
between
species.
We
also
estimate
past
macroevolutionary
shifts
direction/intensity
through
shark
phylogeny.
were
unable
to
find
evidence
significant
early
sharks
hypothesise
derived
state
clade,
has
evolved
independently
observed
other
vertebrates.
Moreover,
no
relationship
testes
mass
or
oceanic
depth
sharks.
However,
support
previous
speculation
an
important
determinant
interspecific
This
vertebrates
thought
be
trends,
with
role
clades
being
inconsistent
at
best.
phylogenetic
distribution
among
superficially
similar
vertebrate
clades,
relative
importance
selective
pressures
underlying
its
evolution
appears
differ.
Language: Английский
Age and Growth of the Shortfin Mako Shark, Isurus oxyrinchus (Rafinesque, 1810), in the Ecuadorian Pacific Ocean
Fisheries Management and Ecology,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 12, 2025
ABSTRACT
The
shortfin
mako
shark
(
Isurus
oxyrinchus
)
is
a
widely
distributed
predatory
species.
However,
critical
aspects
of
its
biology
remain
poorly
understood
in
several
regions,
including
the
Ecuadorian
Pacific
Ocean,
where
it
one
most
commonly
captured
Vertebral
samples
238
specimens
were
analyzed,
119
females
(82–228
cm
TL;
0–15
years),
115
males
(76.4–248
0–16
and
4
unsexed
individuals
(194–215
10–14
years).
von
Bertalanffy
model
provided
best
fit
for
L
∞
271.31
TL,
0
=
75.85
k
0.10
year
−1
),
347.53
76.04
0.06
).
results
indicated
sexual
dimorphism,
with
reaching
larger
size
exhibiting
slower
growth
rates
compared
males.
Ocean
grew
slow,
based
on
life
history
characteristics,
vulnerable
to
overexploitation,
thereby
necessitating
harvest
management
sustain
fishery.
Language: Английский
Misspecifying Sex‐Structured Dynamics in Stock Assessment Models
Fish and Fisheries,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 28, 2025
ABSTRACT
Sex‐specific
variation
in
population
demography
and
life‐history
traits
(e.g.,
growth,
natural
mortality)
is
common
many
fish
populations.
Differences
these
processes
by
sex
can
dictate
dynamics
influence
how
harvesters
interact
with
the
resource.
Across
various
fisheries
management
systems,
stock
assessment
models
(SAMs),
which
mathematically
represent
age
and/or
size
structure,
are
widely
utilised
to
estimate
status
provide
sustainable
harvest
recommendations.
However,
few
studies
have
examined
implications
of
alternative
modelling
assumptions
when
incorporating
sex‐specific
SAMs.
For
instance,
impacts
simultaneously
ignoring
variations
selectivity,
mortality
on
SAM
performance
not
been
explored.
In
this
study,
a
simulation‐estimation
framework
was
developed
for
sexually
dimorphic
to:
(1)
assess
consequences
sexual
dimorphism
(i.e.,
mortality,
selectivity)
benefits
using
catch
data
inform
estimation
processes,
(2)
evaluate
incorrect
regarding
ratio
at
birth,
(3)
develop
advice
parameterising
observation
likelihoods
describe
composition
data.
Correctly
led
more
robust
estimates
advice.
Conversely,
SAMs
yielded
biased
biomass
Collectively,
our
results
underscore
that
oversimplified
about
lead
poor
Moreover,
emphasise
need
routine
collection
support
development
biologically
realistic
models.
Language: Английский
The adaptability of facultative parthenogenesis and ‘multiple embryos per eggcase’ as alternative reproductive strategies in Chondrichthyes
Royal Society Open Science,
Journal Year:
2025,
Volume and Issue:
12(4)
Published: April 1, 2025
Chondrichthyans
(sharks,
rays
and
chimaera)
are
a
fascinating
case
study
through
which
to
examine
reproductive
biology.
While
most
vertebrate
lineages
have
converged
upon
either
placental
viviparity
or
oviparity,
chondrichthyans
exhibit
unparalleled
diversity
in
mode
other
aspects
of
Despite
this,
our
understanding
variation
this
clade
remains
incomplete.
Namely,
several
'unusual'
traits
been
repeatedly
observed
some
chondrichthyan
taxa,
but
we
little
no
their
adaptive
value.
Here,
I
focus
on
two
(facultative
parthenogenesis
the
deposition
multiple
embryos
with
separate
yolks
within
single
eggcase
(MEPE)),
theoretically
result
exponential
increases
fecundity.
discuss
theoretical
fitness
consequences
these
traits,
range
species
eco-evolutionary
contexts
they
documented
major
open
questions
regarding
prevalence
evolutionary
consequences.
It
appears
likely
that
both
facultative
MEPE
at
least
taxa
ecological
contexts.
However,
additional
data
needed
determine
true
effect
lifetime
fecundity,
frequency
occur,
potential
population-level
effects
cues
triggers
might
favour
switches
from
'typical'
sexual
reproduction
MEPE.
Language: Английский
Bayesian estimation of the age and growth of the pelagic thresher shark (Alopias pelagicus) from the Mexican Pacific
Environmental Biology of Fishes,
Journal Year:
2024,
Volume and Issue:
107(9), P. 927 - 943
Published: Sept. 1, 2024
Language: Английский
Sharks Violate Rensch's Rule for Sexual Size Dimorphism
Integrative Organismal Biology,
Journal Year:
2024,
Volume and Issue:
6(1)
Published: Jan. 1, 2024
Systematic
trends
in
body
size
variation
exist
a
multitude
of
vertebrate
radiations,
however
their
underlying
ecological
and
evolutionary
causes
remain
poorly
understood.
Rensch's
rule
describes
one
such
trend-in
which
the
scaling
sexual
dimorphism
(SSD)
depends
on
sex
is
larger.
Where
SSD
male-biased,
should
scale
hyperallometrically,
as
opposed
to
hypoallometrically
where
female-biased.
The
evidence
for
mixed,
comes
from
small
subset
total
diversity.
We
conducted
first
empirical
test
sharks,
seeking
confirm
or
refute
long-hypothesied
trend.
find
that
sharks
violate
rule,
magnitude
increases
with
despite
predominantly
exhibiting
female-biased
SSD.
This
adds
growing
literature
clades
appear
not
follow
suggesting
absence
single,
conserved
trend
amongst
vertebrates.
It
likely
selection
associated
fecundity
results
"inverse
rule"
observed
although
additional
studies
will
be
required
fully
reveal
factors
this
clade.
Language: Английский