Final answer:
Brittle stars can drop their arms through a process called autotomy, using it as a defensive mechanism to escape predators. These dropped arms can regenerate over time, and brittle stars can also reproduce asexually through fragmentation, similar to other echinoderms and invertebrates.
Step-by-step explanation:
Can Brittle Stars Drop Their Arms?
Brittle stars, members of the class Ophiuroidea, have the capability to drop their arms as a defensive mechanism. This process is known as autotomy. The arms of brittle stars are long, thin, and flexible, without containing any vital organs, which allows the animal to survive even if an arm is lost. When a predatory threat is present, a brittle star can intentionally detach an arm to distract the predator, giving it a chance to escape. Drop arms of brittle stars are capable of regeneration over time.
Moreover, brittle stars have been observed to reproduce asexually through fragmentation, a method where a part of an organism breaks off and develops into a new individual. This is illustrated in sources like Figure 34.4 and 43.4, which show a sea star's fragmented arm leading to the development of a new sea star. While sea stars are not the same as brittle stars, they share this remarkable aspect of echinoderm biology, indicating a survival strategy used broadly in this phylum.
Fragmentation is not exclusive to brittle stars and sea stars; it also occurs in other invertebrates such as annelid worms, turbellarians, and poriferans, aiding their survival and proliferation in their respective ecosystems.