Related Experiment Video
Updated: Feb 15, 2026

The Barnacle Balanus improvisus as a Marine Model - Culturing and Gene Expression
Published on: August 8, 2018
A COMPARATIVE STUDY OF THE CEMENT GLANDS IN SOME BALANID BARNACLES (CIRRIPEDIA, BALANIDAE)
Abstract:
1. The histological characteristics of the cement gland cells of barnacles have been compared in B. nubilis, B. psittacus, B. eburneus, B. balanoides and B. amphitrite. 2. In B. balanoides, the cement gland cells show a very simple composition; they are situated at the base of the animal and the secretion appears scattered throughout the cytoplasm. The cement apparatus of B. amphitrite and B. eburneus looks like that of B. tintinnabulum, but in B. psittacus and B. nubilis the cement gland cells appear more complex. 3. The extrusion of the cement secretion is brought about by muscle fibers that pass through the connective tissue, and in B. psittacus and B. nubilis by elastic fibers around the secondary and principal canal systems.
Related Concept Videos
Hydration of Cement
Soundness of Cement
Portland Cement
Fineness of Cement
Direct...
Strength of Cement
For compressive strength tests, ASTM C 109-05 standards prescribe a cement-sand mix ratio of 1:2.75 and a water/cement ratio of 0.485 for making 2-inch cubes. These cubes are mixed, cast, and cured in saturated lime water at 23°C until testing. Flexural strength testing, outlined in...
Types of Cement I
Type I (Ordinary Portland Cement) is widely used for general construction where special properties are not required. It has moderate sulfate resistance and heat of hydration.
Type II (Modified Cement) offers moderate resistance to sulfate attack and a lower rate of heat development compared to Type I. It is suitable for structures in...

