Final answer:
The glomerular capsule (Bowman's capsule) is usually not found in marine teleosts. It surrounds the glomerulus and is responsible for filtration in the renal system. The correct answer is a.
Step-by-step explanation:
The correct answer is a. Glomerular capsule. The glomerular capsule, also known as Bowman's capsule, is a part of the nephron in the kidney. It surrounds and encapsulates the glomerulus, which is responsible for filtration of blood in the renal system.
The other options listed - proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting duct - are all structures that are found in marine teleosts. These are essential components of the nephron that play a role in filtration, reabsorption, and secretion in the renal system.