Utilization of muddy detritus as organic matter source by the fan mussel Pinna nobilis.

Abstract

Knowledge of the feeding habits of marine species is fundamental for a better understanding of their relationship with the environment. Although phytoplankton has traditionally been reported as the main food source consumed by the Mediterranean fan mussel Pinna nobilis, recent studies have revealed that detritus represents an important food source for this species. We analysed the degree of acceptance of muddy detritus and the utilisation of its organic matter (OM) by P. nobilis on a group of 21 individuals [30.3-59.7 cm of total shell height (Ht)]. The specimens were collected between July and September 2012 in two areas (43°04´25" N; 5°46´7" E and 43°04´34" N; 5°47´32" E) of the Embiez archipelago, north-western Mediterranean (France). Our studies show that P. nobilis retains high quantities of OM from muddy detritus (47.50 ± 11.23% of filtered OM) irrespective of shell size. Smaller individuals, however, actively filter more detritus than large ones. The values of retained OM, together with previous studies on stomach contents, suggest that muddy detritus is a more important OM source than phytoplankton for this species.

The Pen Shell, Pinna nobilis

“…These results agree with stomach contents analyses conducted by Davenport et al (2011). Interestingly, P. nobilis retains a high proportion of ingested organic matter (OM) from detritus (48.01 AE 13.69% of filtered OM irrespectively of shell size) and this could be the main source of OM for the species (Trigos et al, 2014a). Enhanced pools of suspended matter within Posidonia canopies increase the food supply to P. nobilis, which may provide an explanation for their close association with seagrasses as habitat .…”

“…The ecological role of P. nobilis is of importance as it filters large amounts of detritus and retains a high percentage of its organic matter (Trigos et al, 2014a), contributing to water clarity. It also provides a hard type of substrate in soft-bottom areas, thus increasing the variety of environments and providing a surface that can be colonized by other (floral and faunal) benthic species.…”

Ultrastructure, phylogeny and histopathology of two novel haplosporidians parasitising amphipods, and importance of crustaceans as hosts

“…However, there is significant evidence of the impact of haplo sporidians on non-cultured species from a wide range of environments. Infection with H. pinnae appears to be a key factor in the decline of the fan mussel Pinna nobilis in the Mediterranean Sea (Trigos et al 2014, Catanese et al 2018. In addition, there may be reduced bioturbation of sediments as a consequence of polychaetes becoming infected by H. parisi and H. scolopli (Ormières 1980, Paramor & Hughes 2004, or even changes in the population structure of important invertebrate predators such as the common shore crab Carcinus maenas infected by H. littoralis (Stentiford et al 2013).…”

Temperature regulates the switch between light-synchronized and unsynchronized activity patterns in the subtidal bivalve Pinna nobilis

“…The four individuals of each tank were fed automatically using pumps controlled by ProfiLux 3.1T. The daily doses of food for each tank were composed by a mixture of 30 g of mud (10.0% ± 2.4% of organic matter content) and 40 ml of an algae concentrate (Reefphyto®-5 live species phytoplankton) (Trigos, 2016;Trigos et al, 2014). The doses were dissolved in 3 l of water and administered in 4 equal doses every 6h.…”