Furthermore, certain viruses can cleave host cell H3 [ 13, 14], and antimicrobial peptides derived from the N-terminal region of various histones (e.g., H2A, H2B, H1) have been identified in several organisms, including fish [ 15- 20], molluscs [ 21, 22], frogs [ 23], and even from the gastrointestinal tract [ 24] and wound fluids [ 25] of humans.
The NPFs have been found in platyhelminths [ 47, 48], molluscs [ 49, 50] and insects [ 51].
Photoreceptors of both the ciliary and microvillar type have been found in annelids [ 31, 32], molluscs [ 33, 34] and tardigrades [ 20].
To date, the only universal response to heat stress documented is the production of heat shock proteins (HSPs), often called the heat shock response (HSR) [ 45] and these genes are often monitored as a measure of environmental stress in molluscs [ 4, 13, 14, 17, 18, 22].
Multiple-X chromosomes occur widely in vertebrates and invertebrates, for example in monotremes (Platypus) [ 14], howler monkeys (Aloutta) [ 15], fishes [ 16], gastropod molluscs [ 17, 18], spiders [ 19], Lepidoptera [ 20] and several groups of Coleoptera [ 21- 24].
However, the presence of several 5S rDNA variants has been reported in such diverse taxa as molluscs [ 8, 12, 13, 67], echinoderms [ 68] and arthropods [ 10].
In most lophophotrochozoan larvae, the apical organ consists of only a few serotonin-like immunoreactive flask-shaped cells (annelids: [ 28- 31]; molluscs: [ 32- 34]; polyclad flatworms: [ 35]; ectoprocts: [ 36, 37]; brachiopods: [ 9, 38]; see [ 27] for review).
It is a common phenomenon described for many animal clades (see e.g., [ 4- 13]), including molluscs [ 1, 14- 19].
In some cases, inefficient or nonexistent detoxification processes may be responsible for high BCF values (e.g. TBT in molluscs) [41, 42].
In invertebrates, haemocytes from insects [41] and molluscs [42] are known to affect the scavenger receptor-mediated uptake of pathogens and apoptotic cells.
Moreover, 210Po concentration in the soft tissue of molluscs (10.36 215.60 Bq kg− 1 dry weight) was far higher than that in fish muscle (0.05 7.49 Bq kg− 1 wet weight).
