Tidal and seasonal patterns in the chondrophore
of the soft-shell clam Mya arenaria.
(Gastropoda); Carinaria cithara Benson 1835 (Heteropoda); a chondrophore
, Velella velella (Hydrodia); Lepas spp.
For studies of Mya arenaria, sections were made of the chondrophore, an internal structure projecting from the hinge region.
Both the shell and the chondrophore of Mya arenaria contain daily growth patterns; however, the growth patterns in the chondrophore are much better preserved than those in the main shell.
Shell lengths at age, estimated from chondrophore heights and fit to a von Bertalanffy growth model, indicated a latitudinal gradient in growth and asymptotic size.
Chondrophore height (CH)-shell length (SL) relationships for clams from each region were also determined, which allowed growth patterns to be examined.
2) from a cut surface of the chondrophore
2011), in the internal chondrophore
(hinge plate) of the shell (Shaul & Goodwin 1982).
Because the exterior portions of the valves are subject to erosion, potentially erasing the earliest growth bands, the interior chondrophore
, or hinge plate, was excised from the right valves using a handheld abrasive cutoff wheel.
3A), visible inside the chondrophore
, and no teeth.
groenlandicus: (1) reading the external rings on the shell, (2) counting the growth rings on thin sections of the chondrophore
, and (3) counting growth rings of whole shell sections.
Internal growth bands are more clearly defined and easier to count in shell structures such as hinge plates and chondrophores
(Palacios et al.