Meet the basket star, an enigmatic and mesmerizing creature that resides deep within the ocean’s depths. With its delicate and intricate arms stretching out like celestial explosions, this marvel of marine biology has captivated scientists and ocean enthusiasts alike. Join us on a journey to explore the unique facts about these ethereal creatures, and uncover the secrets that lie beneath the waves.
Class: Ophiuroidea
Order: Phrynophiurida
1. They are branched
Although called “starfish,” the basket star does not belong to the true starfish family. It is, in fact, a type of brittle star characterized by its branched arms, often known as basket-shaped brittle stars. As a member of the echinoderm group, it shares the characteristic five-fold symmetry and possesses a skeleton typically composed of calcium carbonate plates, forming a rigid outer covering.
Nevertheless, this particular species exhibits unique traits that distinguish it from both starfish and other brittle stars. They have intriguing anatomy with usually 5 arms that extend outward from a central disk. The arms grow in a twisted and knotted manner, creating a basket-like structure. Typically, each arm consists of dual primary branches accompanied by numerous smaller branches sprouting from the main ones. These branches boast their own sets of sub-branches, each adorned with small barbs at their tips.
Similar to other echinoderms, these basket starfish do not possess brains or blood. They utilize their water vascular system for gas exchange.
Cre: on pic
There exist more than 80 species of basket stars, each showcasing diverse physical characteristics. Their sizes range significantly, with some being as tiny as 1 inch (2.5 cm) across, while others can reach up to 3 feet (1 meter) in size. These animals display a wide array of colors, including shades of orange, brown, pink, red, white, and other vibrant hues, which are frequently observed.
Unlike other sea stars, basket stars lack tube feet for locomotion. Instead, they employ their lengthy arms as legs to move at a slow pace across surfaces like coral reefs. Although these species are brittle stars, people still don’t know whether they are bioluminescent or not.
2. Basket star Habitat
Basket stars can be encountered in oceans across the globe, but their highest densities are observed in the region between Australia and Africa. These fascinating creatures live in various habitats, ranging from shallow tidal pools, usually no deeper than a few hundred feet, to the profound depths of the ocean, reaching as far down as 12,000 feet.
They tend to live alone or together on the sea floors with powerful currents as their primary dwelling locations. These captivating creatures rely on their long arms, which double as legs, to move gracefully across surfaces. They possess an impressive skill of firmly anchoring themselves to rocks and coral, thanks to the hook-like spines that adorn their arms.
When basket stars are out of water, they can still live for a really short time.
3. Diet
The giant basket star is carnivorous species. They mainly eat zooplankton, worms, and a diverse array of small crustaceans and mollusks. Whenever food becomes scarce in a particular area, it moves to another location in search of a more favorable hunting ground. This adaption has played a significant role in its widespread distribution across the globe. The ocean stars display nocturnal behavior, primarily hunting at night.
These species have a unique hunting strategy. Rather than actively pursuing its prey, they patiently stay in one spot, waiting for an opportunity. Once the prey comes within reach, they employ their arms to form a funnel-shaped trap, efficiently capturing the prey with minimal effort. With arms armed with barbs, these creatures ensnare the prey by surrounding it with a layer of mucus and then pulling it into their mouths.
The basket star’s secondary branches, which are extensively branched, play a crucial role in catching the prey. On the other hand, the larger primary branches act as collecting arms, aiding in securing the captured food.
Basket stars have to face many predators in their habitats, such as sea otters, large fish, and sea urchins. They also use other defense mechanisms to protect themselves, and detaching arms is one of them. Like starfish, these basket stars will shed one or more of their arms, effectively getting away from predators’ catch. These arms will be regenerated at a later time. Their remarkable regenerative capability guarantees their survival in the ocean.
When confronted with threats, they adopt a defensive posture by enveloping their arms around their body, forming a compact ball to shield themselves from potential enemies. Moreover, these species employ a distinct and ingenious tactic to fend off attackers, as they release a toxic and adhesive mucus that discourages other animals from pursuing them.
They’re also facing a substantial risk from climate change as any changes to their habitat could imperil their survival.
4. Reproduction
Basket starfish exhibit diverse reproductive strategies across different species. Certain species engage in sexual reproduction, while others rely on asexual methods.
During sexual reproduction (spawning), these basket starfish release their gametes (eggs or sperm cells) into the water columns under the cover of night. The fertilization takes place outside when the sperm cells of males meet the eggs of females. Once fertilized, the eggs undergo development into planktonic larvae, which then drift along with ocean currents until they eventually settle on the seabed.
During their juvenile stage, the animals inhabit the seafloor, where they sustain themselves by consuming small organisms. As they progress into adulthood, their arms elongate, and they adopt the feeding strategy typical of grown individuals. On average, the lifespan of basket stars is approximately 35 years.
Reference: lifexen.com
