Arm regeneration in two species of cuttlefish Sepia officinalis and Sepia pharaonis

Abstract

To provide quantitative information on arm regeneration in cuttlefish, the regenerating arms of two cuttlefish species, Sepia officinalis and Sepia pharaonis, were observed at regular intervals after surgical amputation. The third right arm of each individual was amputated to ~10-20 % starting length. Arm length, suction cup number, presence of chromatophores, and behavioral measures were collected every 2-3 days over a 39-day period and compared to the contralateral control arm. By day 39, the regenerating arm reached a mean 95.5 ± 0.3 % of the control for S. officinalis and 94.9 ± 1.3 % for S. pharaonis. The process of regeneration was divided into five separate stages based on macroscopic morphological events: Stage I (days 0-3 was marked by a frayed leading edge; Stage II (days 4-15) by a smooth hemispherical leading edge; Stage III (days 16-20) by the appearance of a growth bud; Stage IV (days 21-24) by the emergence of an elongated tip; and Stage V (days 25-39) by a tapering of the elongated tip matching the other intact arms. Behavioral deficiencies in swimming, body postures during social communication, and food manipulation were observed immediately after arm amputation and throughout Stages I and II, returning to normal by Stage III. New chromatophores and suction cups in the regenerating arm were observed as early as Stage II and by Stage IV suction cup number equaled that of control arms. New chromatophores were used in the generation of complex body patterns by Stage V. These results show that both species of cuttlefish are capable of fully regenerating lost arms, that the regeneration process is predictable and consistent within and across species, and provide the first quantified data on the rate of arm lengthening and suction cup addition during regeneration.

Reversion to developmental pathways underlies rapid arm regeneration in juvenile European cuttlefish, Sepia officinalis (Linnaeus 1758)

“…Ten days after surgery, animals were terminally sampled after euthanasia in FSW containing 10% EtOH until ventilation ceased, followed by cerebral bisection and decapitation, and weighed. The qualitative stage of arm regeneration was assessed according to previously established guidelines (Tressler et al, ). The leftmost limb was removed at its root, and immediately placed in 4% paraformaldehyde (PFA) in FSW (for histology), or flash‐frozen in liquid nitrogen for RNA processing or protein synthesis analysis.…”

“…For over 160 years, scientists have been fascinated by the regenerative capacities of animals (Lange, ; Steenstrup, ), especially coleoid cephalopods such as the European cuttlefish, Sepia officinalis (Linnaeus 1758). Seemingly independent of their age in regard to functional capacity, cuttlefish can replace a damaged or amputated arm with an indistinguishable copy within weeks to months (Tressler, Maddox, Goodwin, Zhang, & Tublitz, ). Understanding this specific, complex, and reliable process would be invaluable in efforts to attain similar outcomes in medicine.…”

Molecular Determinants of Cephalopod Muscles and Their Implication in Muscle Regeneration

“…More recent studies on muscle regeneration in cephalopods revealed several new and interesting aspects of the regenerative processes specifically in appendages. Arm regeneration within and across species seems to follow predictable and consistent morphological changes that lead to the restoration of full adult form and function (Lange, 1920; Fossati et al, 2013, 2014; Tressler et al, 2014; Shaw et al, 2016). These studies on the morphological processes of cephalopod arm regeneration have provided a useful basis for the examination of the molecular pathways underlying cephalopod arm morphogenesis.…”

“…Cephalopod mollusks offer a particularly viable alternative to canonical limb regeneration models due to their similarities in early arm development to vertebrate models, their complex arm structure and function, their fast and efficient regenerative capabilities and the relatively simple animal maintenance and handling (Matzner et al, 2000; Yekutieli et al, 2005a,b; Kier and Stella, 2007; Kier and Schachat, 2008; Fossati et al, 2011; Zullo et al, 2011; Tressler et al, 2014; Nödl et al, 2015, 2016). …”

The Digestive Tract of Cephalopods: a Neglected Topic of Relevance to Animal Welfare in the Laboratory and Aquaculture

“…The literature also has examples of feeding an individual “meal,” but providing food on multiple occasions during the day. For example, Yacob et al (2011) report feeding S. officinalis on frozen shrimp and live zebra fish twice daily and in another cuttlefish study animals were fed frozen krill and silversides by hand 3–4 times a day (Tressler et al, 2014). …”