Proteogenomic Characterization of the Cement and Adhesive Gland of the Pelagic Gooseneck Barnacle Lepas anatifera

We focus on the stalked goose barnacle L. anatifera adhesive system, an opportunistic less selective species for the substrate, found attached to a variety of floating objects at seas. Adhesion is an adaptative character in barnacles, ensuring adequate positioning in the habitat for feeding and reproduction. The protein composition of the cement multicomplex and adhesive gland was quantitatively studied using shotgun proteomic analysis. Overall, 11,795 peptide sequences were identified in the gland and 2206 in the cement, clustered in 1689 and 217 proteinGroups, respectively. Cement specific adhesive proteins (CPs), proteases, protease inhibitors, cuticular and structural proteins, chemical cues, and many unannotated proteins were found, among others. In the cement, CPs were the most abundant (80.5%), being the bulk proteins CP100k and -52k the most expressed of all, and CP43k-like the most expressed interfacial protein. Unannotated proteins comprised 4.7% of the cement proteome, ranking several of them among the most highly expressed. Eight of these proteins showed similar physicochemical properties and amino acid composition to known CPs and classified through Principal Components Analysis (PCA) as new CPs. The importance of PCA on the identification of unannotated non-conserved adhesive proteins, whose selective pressure is on their relative amino acid abundance, was demonstrated.

Possible Transoceanic Rafting of Lepas Spp. on an Unopened Plastic Bottle of Chinese Origin Washed Ashore in Victoria, Australia

Floating marine debris and litter act as a vector transporting various species across long distances. The present study reports possible transoceanic rafting of a small colony of barnacles on an unopened plastic bottle of Chinese origin found washed ashore on the Ninety Mile Beach in Victoria, Australia. The crustaceans attached were identified to be the goose barnacle Lepas pectinata. Based on the number and size of the colony the marine pollutant was estimated to adrift for several months. We hypothesised the origin of the flotsam, especially the barnacles and how it made its way from the Pacific to be washed ashore in Australia. Furthermore, we identified two types of microbes, Vibrio alginolyticus and Vibrio parahaemolyticus, associated with the Lepas pectinata growing on the bottle. This study appears to be the first report of possible transoceanic rafting on unused plastic pollutants and highlights the potential environmental threats caused by plastic.

The Quantitative Proteome of the Cement and Adhesive Gland of the Pedunculate Barnacle, Pollicipes pollicipes

Adhesive secretion has a fundamental role in barnacles’ survival, keeping them in an adequate position on the substrate under a variety of hydrologic regimes. It arouses special interest for industrial applications, such as antifouling strategies, underwater industrial and surgical glues, and dental composites. This study was focused on the goose barnacle Pollicipes pollicipes adhesion system, a species that lives in the Eastern Atlantic strongly exposed intertidal rocky shores and cliffs. The protein composition of P. pollicipes cement multicomplex and cement gland was quantitatively studied using a label-free LC-MS high-throughput proteomic analysis, searched against a custom transcriptome-derived database. Overall, 11,755 peptide sequences were identified in the gland while 2880 peptide sequences were detected in the cement, clustered in 1616 and 1568 protein groups, respectively. The gland proteome was dominated by proteins of the muscle, cytoskeleton, and some uncharacterized proteins, while the cement was, for the first time, reported to be composed by nearly 50% of proteins that are not canonical cement proteins, mainly unannotated proteins, chemical cues, and protease inhibitors, among others. Bulk adhesive proteins accounted for one-third of the cement proteome, with CP52k being the most abundant. Some unannotated proteins highly expressed in the proteomes, as well as at the transcriptomic level, showed similar physicochemical properties to the known surface-coupling barnacle adhesive proteins while the function of the others remains to be discovered. New quantitative and qualitative clues are provided to understand the diversity and function of proteins in the cement of stalked barnacles, contributing to the whole adhesion model in Cirripedia.

Diameter of the base of the capitulum as a biometric variable of the goose barnacle Pollicipes pollicipes (Gmelin, 1789) (Cirripedia, Lepadomorpha)

Owing to the peculiar morphology of the goose barnacle Pollicipes pollicipes (Gmelin, 1789), many different biometric variables have been used in its study. The lack of a standard morphological variable makes it difficult to compare results from different authors. This aspect takes on even greater importance, since the goose barnacle is a commercially exploited species and must be regulated with clear-cut technical measures related to its biology. The need to measure a large quantity of specimens in the management and control of the fishery calls for a biometric variable that can be processed easily and requires little training. The base of the rostrum and the apex of the subcarina form two conspicuous clefts in the capitulum of the goose barnacle, allowing a calliper to be fitted quickly and easily. The results of this study showed that the diameter of the base of the capitulum (DBC), defined as the distance between these two clefts, may be considered a consistent variable both when the same specimen is measured by two different technicians and when the measurements taken from a fresh specimen are compared with the measurements taken after the specimen has been frozen and then thawed. In order to make comparisons easier, two linear equations have been found to relate DBC and two of the more usual biometric variables: rostral-carinal distance (RC) and capitulum height (CH). The mean length at sexual maturity was also calculated in terms of DBC (13.35 mm) for specimens collected on the Galician coast (NW Spain).

Assessment of goose barnacle (Pollicipes pollicipes Gmelin, 1789) stocks in management plans: design of a sampling program based on the harvesters' experience

Parada, J. M., Outeiral, R., Iglesias, E., and Molares, J. 2012. Assessment of goose barnacle (Pollicipes pollicipes Gmelin, 1789) stocks in management plans: design of a sampling program based on the harvesters' experience. – ICES Journal of Marine Science, 69: 1840–1849. Management plans of coastal marine resources require a wealth of information on socioeconomic topics, harvesting activities, population dynamics, and stock status. Moreover, the information provided by technical experts must take into account the needs of the managers. It must also adapt to schedules to serve a useful purpose. In many cases, the methodologies used by research teams are not directly applicable as they may be too complicated, aimed at specific objectives related to basic scientific work, or too costly to apply to long-term monitoring of extensive shellfish beds. Also, rocky coastlines exposed to heavy wave action preclude the use of sampling techniques that involve time-consuming data collection. This paper proposes a quick and simple methodology for gathering data in the field, based on the knowledge of the harvesters, to obtain stock assessments in keeping with their information needs. This methodology uses coverage percentage as an abundance index and weighting factor for the biometric information gathered from 50 specimens in each sampling. The sampling design uses the knowledge of the harvesters to define homogeneous strata. The results are in agreement with both the scientific-technical knowledge and the harvesters' knowledge of the populations being analysed.