Acorn barnacle

Fig. 4.2 An acorn barnacle lives inside a permanent home of protective calcium plates.

Finally, a novel proxy is introduced by Craven et al, who provide empirical data to show that stable carbon isotopic variability in organic tissue of the inter-tidal acorn barnacle, Semibalanus bala-noides, is related to immersion/emersion times. With more work, this technique could potentially provide critical information about small-scale, but rapid, variations in past sea-level such information is crucial for assessing the likely impact of anthropogenic-induced climate change. 

Isotopic variability in the intertidal acorn barnacle Semibalanus balanoides a potentially novel sea-level proxy indicator... 

Abstract We report variations in the and 8 0 values of barnacle skeletal carbonate as well as the 8 C and 8 N value of tissue from specimens of the acorn barnacle S. balanoides, as a function of elevation within its living range on the Isle of May, Scotland. Individuals were sampled over a 3.50 m range at 0.25 m intervals (1.00-4.50 m above ordnance damm). Carbonate 8 0 values (2.44 + 0.13%o [Icr], n = 45) and tissue 8 N values (8.17 + 0.42%o, n = 15) do not vary systematically with elevation. The 8 C value of shell carbonate increases with elevation by c. %c (total range — 0.77%o to +0.63%o), but the variability between samples at the same elevation suggests that this relationship will be of limited use in constraining palaeo-elevation. 

S. balanoides is an intertidal acorn barnacle with a living-range generally extending between low and high water marks. It is a northern hemisphere... 

Davenport, J. Irwin, S. 2003. Hypoxic life of intertidal acorn barnacles. Marine Biology, 143, 555-563. 

Barnacles are crustaceans that show very special adaptations to a sessile mode of life. Acorn barnacles that are cemented to the substratum with the whole calcareous or noncalcareous base are frequently found on ship hulls - most of them belong to the family Balanidae. The adhesive of these barnacles is considered to be among the most durable and toughest connections in the living aquatic world [1], and it is therefore also called cemenf. 

Prendergast GS, Zum CM, Bers AV, Head RM, Hansson LJ, Thomason JC (2009) The relative magnitude of the effects of biological and physical settlement cues for cypris larvae of the acorn barnacle, Semibalanus balanoides L. Biofouling 25 35 14... 

Acorn barnacles at 1750 animals/m were recorded as fouling species on the panels exposed by Short et al. [59] in Plymouth Sound (50°N 4°W), together with worms and algae. The full list of fouling organisms is given in Table 7.4. 

Porphyra linearis (Bangiaceae) Porphyra umbilicalis (Bangiaceae) Fauna Phylum Annelida (worms) Pomotoceros triquetes Phylum Arthropoda Balanus crenatus (acorn barnacles)... 

Thoracica Balanus (acorn barnacle), Chthamalus, Lepas (barnacle), Pollicipes (barnacle). 

Looking all around you in the tide pools, you can see so many different creatures sticking themselves to the rocks—tube worms, acorn barnacles, gooseneck barnacles, limpets, mussels, seaweed, periwinkles, starfish, and anemones (see Figure 13.1). We don t yet know how most of them stick. So there is a lot of fun science for you to explore in the future. For now, let me give you an overview of what we do know about these critters. We scientists have more information on mussel adhesive than any other marine system. 

Barnacles. After mussels, we probably know the most about how the common acorn barnacle makes its cement. You can see barnacles on a rock in Figure 13.8. Here, too, the material is based on cross-linked proteins. However, there is no DOPA in the barnacle cement proteins. Perhaps the thiol groups of cysteine amino acids (i.e., RSH groups) are oxidizable to disulfides and take part in an oxidative protein cross-linking to form barnacle cement, although we do not yet know for sure. Hair perms rely on just this type of disulfide formation to link hair and hold it in a given configuration. Barnacle... 

Muramoto, K., and Kamiya, H., 1990, The positions of the disulfide bonds and glycosylation site in a lectin of the acorn barnacle Megabalanus rosa, Biochim. Biophys. Acta 1039 52-60. 

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