Linckia multifora sea stars
SS1 (large specimen) – appears to have lost an 8mm portion of one arm. This could be part of the sequential loss of parent arms for asexual reproduction, commonly seen in this genus and previously observed by our team. It is, however, typically the largest arm that autotomises, resulting in loss of the whole of the arm (Crawford 2007). So in this instance, the missing arm portion may have been predated by another individual in the aquarium (perhaps the mantis shrimp).
SS3 (large specimen) – slight decrease in average arm length this month of 0.2mm. With continued decrease in growth rates the past few months, this now puts SS3 at the same average arm length as October 2019 when it was 32.8mm. It could be that growth rates are stagnating as the sea star reaches its maximum size, and may indicate that it will soon donate a new arm.
SS4 (autotomised arm) – average increase of 1.2mm this month, and although the parent arm again decreased in size by 2mm, it continues to differentiate its new arms into the ‘comet-phase’.