WWW.WAS.ORG • WORLD AQUACULTURE • SEPTEMBER 2016 57 Additionally, members of this family of worms have the ability to regenerate from severely damaged limbs. An adult Polydora sp. cut into three pieces – head, middle and posterior – can regenerate an entire functional worm from each body piece in 40 days under laboratory conditions (Tinoco-Orta and Cáceres-Martínez 2003). This regeneration phenomenon, called architomy, increases the potential for infestation by these worms. Conventional bacteriological analyses such as Gram stain, (CONTINUED ON PAGE 58) Results and Discussion The polychaete spionids were identified as Boccardia proboscidea by a modification of the fifth setiger, a type of filament in the external body that aids in locomotion and excavation, and also by the presence of branchiae before this structure. Furthermore the 18S rDNA sequences indicated 99 percent similitude and 99 percent identity with sequences of these species deposited in GenBank. This worm is a common polychaete that is distributed along the western coast of North America. It is a species closely related to those mentioned previously associated with similar lesions in cultured abalone in Australia and South Africa. These burrowing worms have several biological characteristics that make their control difficult. The reproductive strategies of these species make them powerful invaders that are difficult to eradicate if they are allowed to spread in aquaculture facilities. B. proboscidea is poecilogonous, a term that refers to a type of development in which a female may produce planktotrophic larvae as well as bottom-crawling juveniles within a single egg capsule. This means that infestation can occur by settlement of planktonic larvae, which easily travel with water currents throughout the aquaculture facility, or by crawling along the bottom into the shell of the host abalone. FIGURE 6. A piece of the chitinolytic layer that covered the perforation extracted from the inner shell. FIGURE 7. Organic material and detritus found under the chitinolytic layer where small pieces of several worms were observed. FIGURE 8. The procedure to extract burrowing worms from organic deposits.
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