Cyprids, barnacle

Harrison, P., Barnacle cyprid behaviour, anatomy and neurophysiology, Ph.D. thesis, University of New South Wales, Sydney, Australia, 1998. 

Settlement of barnacles, especially the now cosmopolitan species Balanus amphitrite, has received extensive attention. Rittschof53 pioneered the investigation of the role of specific soluble peptides released as metabolites into seawater by adult barnacles as larval-settlement stimuli for invertebrate larvae, especially those of barnacles. Cyprid larvae of B. amphitrite are powerfully stimulated to settle to surfaces and walk upon them by the presence of very low concentrations of dissolved peptides with a C-terminal arginine or lysine residue.53-54 However, there are reports of attachment and metamorphosis of cyprids of B. amphitrite, in the absence of a soluble peptide cue,... 

The role of biofilm bacteria in barnacle settlement has been a topic of considerable investigation and discussion (see Sections II and III.C above). Despite numerous studies finding positive associations between biofilms and the settlement of barnacle cyprid larvae, Roberts et al.,198 using shortterm field tests of treated surfaces, found, Although bacterial films can have dramatic effects on settlement of barnacles and bryozoans...they are not essential for colonization by barnacles, bryo-zoans or hydroids. ... 

O Connor, N.J. and Richardson, D.L., Comparative attachment of barnacle cyprids (Balanus amphitrite Darwin, 1854 B. improvisus Darwin, 1854 and B. ebumeus Gould, 1841) to polystyrene and glass substrata, J. Exp. Mar. Biol. Ecol., 183, 213, 1994. 

Aldred N, Phang IY, Conlan SL et al. (2008) The effects of a serine protease, Alcalase (R), on the adhesives of barnacle cyprids (Balanus amphitrite). Biofouling 24 97-107... 

Kalihinol A (108) was originally isolated as an antimicrobial compound from Acanthella sp. collected in Guam. Kalihinol A, and other isocyanides, including kalihinenes X (166), Y (167), and Z (168), as well as 10-formamidokalihinene (169) — all of which were isolated from the Japanese Acanthella cavernosa—were shown to inhibit the larval settiement and metamorphosis at concentrations less than 0.1 pgmP whereas toxicity toward the barnacle cyprids was very low (LD50 values > lOOpgmP ). Antimalarial activity was also reported for other biological activities of kalihinol A. ... 

Prendergast GS, Zum CM, Bers AV, Head RM, Hansson LJ, Thomason JC (2008) Field-based video observations of wild barnacle cyprid behaviour in response to textural and chemical settlement cues. Biofouling 24 449 159... 

Walker G, Yule AB (1984) The temporary adhesion of barnacle cyprids effects of some differing surface characteristics. J Mar Biol Ass UK 64 429-439... 

Figure 4.12 Effect of grafting PHEMA and PPEGMA on PU surfaces. (Top) Reduced microfouling—that is, bacterial cell viability on surface grafted with PHEMA and PPEGMA compared to pristine PU and PU with covalently bound macroinitiator (PU-Br). (Bottom) Reduced macrofoulmg—that is, reduction m the amount of settled, live barnacle cyprids. Source Adapted from Pranantyo et al. [24], with permission from RSC Publishing.

Schumacher, J.F., Aldred, N., Callow, M.E., Finlay, J.A., Callow, J.A., Clare, A.S., and Brennan, A.B. (2007) Spedes-spedfic engineered antifouling topographies correlations between the settlement of algal zoospores and barnacle cyprids. Biofouling, 23, 307-317. 

Maki, J. S., Ding, L., Stokes, J., Kavouras, J. H., Rittschof, D. Substratum/bacterial interactions and larval attachment films and exopolysaccharides of Halomonas marina (ATCC 25374) and their effect on barnacle cyprid larvae, Balanus amphitrite Darwin. Biofouling 2000,16,159-170. 

Cyprid major protein is a larval storage protein necessary for successful metamorphosis. " Production of cyprid major protein was increased in the barnacle Balanus amphitrite following exposure to both nonylphenol and estradiol, suggesting that it may be a potential biomarker of estrogen exposure in invertebrates such as barnacles. " "... 

Styloguanidins, e.g. 135, chitinase inhibitors from the marine sponge Stylotella aurantium, inhibit the moulting of cyprid larvae of barnacles at a concentration of 10 ppm [108]. They are closely related to palauamine (67). 

The bromotyramine derivatives ceratinamide A (136) and psammaplysin A (137) from the sponge Pseudoceratina purpurea inhibit the settlement and metamorphosis of cyprid larvae of the barnacle Balanus amphitrite (ED50 0.10 and 0.27 (Jg/ml). Interestingly, psammaplysin A induces larval metamorphosis of the ascidian Halocynthia roretzi (ED 0o 1.2 (Jg/ml) [74]. 

Mullineaux, L.S. and Butman, C.A., Initial contact, exploration and attachment of barnacle (Balanus amphitrite) cyprids settling in flow, Mar. Biol., 110, 93, 1991. 

For Balanus amphitrite, a waterborne settlement inducer that is more active than the surface-associated settlement factors has been extracted from seawater conditioned with adult barnacles.53 The cyprid settlement responses could be stimulated by peptides bearing C-terminal arginine or lysine residues.54 102 Interestingly, the same barnacle settlement-inducing peptides attract a variety of barnacle predators such as oyster drills.53103... 

Larman, V. N. and Gabbott, P. A., Settlement of cyprid larvae of balaunus Balanoides and Elminus modestus induced by extracts of adult barnacles and other marine animals, J. Mar. Biol. Assoc. U.K., 55, 183, 1975. 

Settlement. The fixation of the larvae of benthic animals does not take place randomly, but is sometimes guided by the presence of immerged substrata of organic substances deposited by adults previously fixed there. Thus, in the case of Balanus balanoides, the cyprid larvae attach themselves to surfaces where earlier barnacles have deposited a complex mixture of mucopolysaccharides and proteins associated to nucleic acids (Crisp, 1974). This mediator is not specific it is produced by several crustaceans smd has therefore received the name arthropodin. A similar phenomenon was described by Nott (1973) for the annelid Spirorbis spirorbis. 

Dreanno C, Kirby RR, Clare AS (2006b) Smelly feet are not always a bad thing the relationship between cyprid footprint protein and the barnacle settlement pheromone. Biol Lett 2 423 125... 

Abstract Many barnacle species are gregarious. This is an essential behavior for those species that can only reproduce by mating with a neighboring barnacle. Proximity of adult barnacles is achieved by gregarious settlement of the cypris larva. The chemical basis of this behavior was established 60 years ago, but attempts to characterize the cue to settlement met with limited success. This chapter presents evidence obtained in recent years that the cue is an a2-macroglobulin-like cuticular protein, detected by cyprids using a tactile chemical sense as they explore the substratum for a suitable settlement site. 

Fig. 22.1 Gregarious settlement of barnacle cypris larvae, (a) Cyprids approach the substratum, perhaps after encountering a waterborne cue released by adults (b) contact with substratum and onset of (c) searching behavior (d) cyprid contacts an adult conspecific and is stimulated to settle by a cuticular protein - the settlement-inducing protein complex (SIPC). The cyprid may return to the plankton at any stage of the sequence (b-d). Drawing by Jorge A. Varela Ramos...

---