The growth of the buccal mass in Sepia officinalis: functional changes throughout ontogeny

Abstract

Due to their small size, juveniles are more likely to show lower absolute levels of performance leading to a potential competitive disadvantage compared to adults. Therefore, juveniles are expected to compensate by showing a higher relative performance, and/or partitioning resources to overcome this performance disadvantage. Here, we investigate the link between ontogeny and feeding performance in the common cuttlefish Sepia officinalis. We explore the changes in beak shape, wear pattern, mechanical properties, muscular anatomy, and bite force during growth from 3-month post hatching to adults. We show that both upper and lower beaks present important ontogenetic shape variation in the rostrum area that might be due to wear induced by feeding. The mechanical properties of the beaks in juveniles indicate greater resistance compared to adults. Tanning observed on the beaks provides reinforcement to areas under high load during biting. In addition, muscle development and relative bite force were found to differ between cuttlefish of different ages, resulting in juveniles having a similar bite force for their size but with a muscular advantage for opening. Finally, an isometric relation is found in the bite force of S. officinalis, with no sign of feeding performance compensation in juveniles. Feeding performance thus does not reflect the ontogenetic shift from a crustacean-based diet in juveniles to a fish-based diet in adults.

A First Record of Lower Jurassic (Toarcian) Coleoid Jaws in Siberia

“…One of smaller concretions from the level 1 m above the Pliensbachian/Toarcian boundary in exposure 4d was found to contain numerous microonychites. Although the lowermost part of black shales throughout the Vilyui River basin lacks ammonites, the age of the studied unit can be deducted through bivalve occurrences, as Kedonella mytileformis collected from the jaw-bearing level is restricted to two lowermost lower Toarcian ammonite zones [23]. Our observations on the belemnite distribution across the succession confirm Repin's statement [22] on the first occurrence of belemnites within the 'Pliensbachian'.…”

“…Specimen No. 1 (MAR 3/1; Figure 4A,B) is an upper jaw having a total length of 14 mm and a height of 9 mm (upper total length, UTL, and upper total height, UTH, respectively according to [23], Figure 1). A well-preserved external plate of the jaw (hood) demonstrates a prominent anterior tip (rostrum) and both lateral wings behind it.…”

Scaling of buccal mass growth and muscle activation determine the duration of feeding behaviors in the marine mollusc Aplysia californica

“…The retractor muscle hypertrophy may be needed to deal with these more difficult foods. In another molluscan species, the cuttlefish ( Sepia officinalis ), buccal mass growth is apparently isometric despite diet changes between juveniles and adults ( Souquet et al, 2023 ).…”

Wear patterns of radular teeth in Loligo vulgaris (Cephalopoda; Mollusca) are related to their structure and mechanical properties

“…These specimens were ordered from a local fish market and came from the North Sea. For this study, we only used animals of the same size (mantle length of 14-15 cm), because it is known that the buccal mass sizes change with body size [106,[121][122][123].…”