Atlantic Mud-piddock (Barnea truncata): description of residence 2023
Document information
Additional Information:
For more information on the Species at Risk Act (SARA), or for additional information on species at risk, please visit the Species at Risk Public Registry.
Recommended citation:
Fisheries and Oceans Canada. 2023. Residence Description for the Atlantic Mud-piddock (Barnea truncata) in Canada. Species at Risk Act Residence Description Series. Fisheries and Oceans Canada, Ottawa. 2 pp.
1 Introduction
The Species at Risk Act (SARA) states that “No person shall damage or destroy the residence of one or more individuals of a wildlife species that is listed as an endangered species or a threatened species, or that is listed as an extirpated species if a recovery strategy has recommended the reintroduction of the species into the wild in Canada.” [section 33].
Also, SARA defines “residence” as: “a dwelling-place, such as a den, nest or other similar area or place, that is occupied or habitually occupied by one or more individuals during all or part of their life cycles, including breeding, rearing, staging, wintering, feeding or hibernating.” [subsection 2(1)]
Sections 2 and 3 below provide a description of the residence for the Atlantic Mud-piddock. The information in those sections was adapted from the “Recovery Strategy for the Atlantic Mud-piddock (Barnea truncata) in Canada” (DFO 2023). The geographic distribution of the Atlantic Mud-piddock is described in the recovery strategy for this species (DFO 2023).
2 Structure, form and investment
The process of constructing a residence begins when the larva settles and actively burrows into the substrate. The presence of a functional foot and a still-functional velum (membrane) in the larval stage suggests mobility allowing for some substrate selection when the larva settles. As the Atlantic Mud-piddock grows and burrows deeper, the size of the burrow increases in diameter resulting in a conical hole that traps the animal inside (figure 1). The adult Atlantic Mud-piddock is unable to fully enclose itself in its shell, and protection is provided by the burrow (COSEWIC 2009).
The Atlantic Mud-piddock's burrow starts at the surface of the substrate and continues to a point below the lower end of the valves (shells) (figure 1). The burrow ends below the valves where the Atlantic Mud-piddock’s foot temporarily anchors to the substrate, enabling the rotation of the shell for the reaming of the burrow (COSEWIC 2009).
The structure and form of the burrow is the residence of the Atlantic Mud-piddock. Their investment is the act of burrowing into the substrate, entering the space and creating the burrow hole that will be occupied for the lifespan of the individual.
Long description
A drawing of a cross section of 2 Atlantic Mud-piddocks in their red mudstone burrows is shown. One Atlantic Mud-piddock is shown in lateral view, the other in ventral view. Each burrow begins as a circular hole in the surface of the red mudstone and continues to a point below the lower end of the shells. The burrows are narrowest at the top, and widen as they descend through the substrate, resulting in a conically shaped burrow.
3 Occupancy and life-cycle function
The Atlantic Mud-piddock occupies its burrow year-round for its entire post-larval lifespan. Life cycle functions including growth, maturation, spawning and feeding all occur from within the burrow (COSEWIC 2009).
Once created, the burrow of an individual Atlantic Mud-piddock is considered its residence year round for its entire adult lifespan.
4 References
- COSEWIC. 2009. COSEWIC assessment and status report on the Atlantic Mud-piddock Barnea truncata in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vii + 42 pp.
- DFO. 2023. Recovery Strategy for the Atlantic Mud-piddock (Barnea truncata) in Canada. Species at Risk Act Recovery Strategy Series. Fisheries and Oceans Canada, Ottawa. vi + 50 pp.