| |
Adaptation
When writing on the adaptations of the
Paralithodes camtschatica, the main adaptations the red king crab are
generally to its environment and habitat, its feeding habits, reproduction, and
its interactions between other species. Through these adaptations, the king
crab is able to survive and populate the many areas it exists.
Environment:
The P. camtschatica has a range of
environments it lives in, from temperate to polar. Even with this temperature
change, the crab’s lifestyle has not been affected in any of these environments,
able to live in warmer areas as well as the polar climates as well. The P.
camtschatica use enzymes that are adapted to support a stable metabolic
rate, keeping catalysis at a normal rate over a variety of temperatures.1 The
main environmental factors the red king crabs are most dependent on are a
plentiful food source and ability of successful reproduction.2 The red king
crabs can also interact better to the environment through the increase in
ability of communication. The crabs have compound eyes, letting them see more
clearly. They also use their sense of touch, being able to feel around their
environment by the antenna on their head. Also, the red king crabs communicate
chemically through pheromones, using the chemicals as either a warning signal or
a sign by the female implying she is ready to mate.3
Feeding Habits:
Red king crabs eat an assortment of food,
foraging anything they may come across, whether a soft sponge, worm, or
echinoderm, or a hard mussel or barnacle. Adaptations to this foraging
lifestyle include the species mouthparts and claws. They are able to eat is
array of organisms because of their ability to crush and hold onto their prey,
by their claws, and manipulate and chew their food by their mandibles, maxillae,
and maxillipeds.4 Also, because of the adult crab’s strong defense by its
carapace, it can wander the depths without much worry of being eaten.5
Metamorphosis and the crab’s different niches for its larvae, juveniles, and
adults is a great factor in food abundance, for there is a small, if any
competition for food between each group. Because of this, the organisms have a
better chance in survival because of the different food sources, the young not
competing for the same food of the adults.6
Reproduction:
The P. camtschatica’s reproductive
system is adapted to its environment through external fertilization and their
clutch size. External fertilization is possible for this species because they
are aquatic and are able to pass the sperm externally without it drying up. The
large clutch size for the red king crab is also important in order to keep
populations high because of the 100,000 to 200,000 larvae hatched, only one of
these typically survive to adulthood.7
This large fatality rate is caused by predation, low food availability, poor
water quality, as well as the many more eternal factors the larvae face.8
Interactions Between Other Species:
The king crab is considered a predator to many species lower on the food chain,
including the echinoderms, sponges, and worms, yet they are also prey to many
other species. Because of this, adaptations have made it possible for the
red king crab to hold its own by the increase in defense and escaping abilities.
During the megalops stage, the juvenile crab use podding to increase their
survival rate, swarming into massive groups. The adult king crab has a
hard carapace covered in spines that keep away predators that are able to
consume its younger relatives.9 Its claws also help ward the predators away
as well, snapping in defense. Also, king crabs use a scattering technique,
that when a predator is near, the crab kicks up mud creating a cloud, making it
practically impossible to find the crab, enabling the crab flee from danger.10
|