Homing and ?ortsteue? (attachment to place) in Patella L. (Gastropoda, Prosobranchia)

Abstract

It is known that numerous gastropods show homing ability. Many limpets return to well defined sites. Patella L. acquires a home spot also on the smooth glass surfaces of aquarium. Before leaving, the limpet scrapes its home, particularly the anterior part of the footprint. After each return it makes characteristic movements with its shell.When homing Patella nearly always retraces its outward track, at least in part; sometimes it reaches its home over the shortest route possible.Site and tracks are marked by chemical substances. The animal orientates itself by contact chemoreception on the track and by distance chemoreception when near its home. Apparently there also exists a kinesthetic mechanism of orientation based on a measurement of distance on the outward journey.At the home spot Patella always manoeuveres exactly into the same position. Often it has to turn or to glide around slightly. It finally settles down with small movements of its shell.The footprint shows chemical differences in a wide marginal zone. Probably, different chemoreceptors on the sole of the foot are associated to the various regions of the footprint.The chemical differentiation of the footprint has the same orientation-value for all individuals of the same size group. In addition there exists an individual marking, shown e.g. by avoidance reactions of alien animals.The individual specificity of the foot's secretum is particularly marked on the tracks, for each Patella follows its own trail only and thus normally reaches its own home. On an uneven substratum this is the only place where the margin of its shell fits the ground exactly.For establishing a home site and keeping to it, several environmental conditions have to be met. Patella settles only on surfaces overgrown with small algae. In an aquarium it favours the sides most exposed to light. On vertical walls the animal is gravity-oriented. Most limpets are attached head-end down. Patella is able to perceive the distance from the water-line, and may orient itself with respect to fixed objects in the aquarium by means of a "Ferntastsinn". When first choosing a home spot on an uneven substratum, the limpet often adjusts its position by turning movements, so that the contacts between shell and ground are as close as possible. Selective growth at the shell's margin then results in a perfect fit to the irregularities of the ground.All prerequisites for the establishment of a home site are also determining the animal's keeping to its home. If changes are introduced with respect to the fitting of the shell to the ground, to the position of neighbouring objects, to water-level, light, or direction of gravity, the animal may leave its home site and reorient itself in an equivalent new one. The attractiveness of the chemical markings of the old site nevertheless compete with all these conditions for some time.Rest and activity are controlled by light-dark and tidal cycles. - Inter-and intraspecific differences were obtained under experimental conditions. Almost all individuals were preferenti...

Snails and their trails: the multiple functions of trail‐following in gastropods

“…Since pedal mucus contains significant levels of protein, polysaccharide and other organic substances (reviewed by Davies & Hawkins, 1998), chemical cues have been proposed to drive trail-following in cases such as homing (Funke, 1968;Cook, 1969Cook, , 1971Cook, , 1979Cook & Cook, 1975;Chelazzi et al, 1985), conspecific aggregation (Trott, 1978;Trott & Dimock, 1978), mate-searching (Peters, 1964;Chase et al, 1978;Cook, 1985a;Johannesson et al, 2010;Ng et al, 2011) and predation (Cook, 1985a(Cook, , 1989Marin et al, 1999;Clifford et al, 2003;Shaheen et al, 2005). In an early study, Sleeper & Fenical (1977) reported a yellow hydrophobic substance (containing three methyl ketones) released in mucus trails of the sea slug Nauanax inermis following its disturbance.…”

Homing to Hibernating Sites in Helix pomatia Involving Detailed Long‐term Memory

“…Trail-following behaviour occurs in terrestrial snails (COOK 1977;CHASE et al 1978) and, together with distant responses to such trails, explains homing to resting places in slugs (GELPERIN 1974;COOK 1979COOK a, 1980. Homing by trail following has also been proved in various aquatic snails (FUNKE 1968;WELLS & BUCKLEY 1972;COOK 1979b, MCFARLANE 1981. However, concerning hibernation in Helix, trail orientation is unlikely because of the long time interval, 4-5 months, between emergence and hibernation, and seems excluded by the results of displacement experiments: snails removed during winter returned to the original hibernating area and not the place where they emerged in spring.…”

“…The hibernation hole is a temporary construction (LIND 1968), and no visible contours are left after 4-5 months, contrary to the permanent resting places of slugs and limpets (FUNKE 1968;COOK 1980;COOK et al 1969). It is therefore likely that Helix does not search for the old sites as such, but responds to a number of previously experienced stimuli which together characterize a goal area associated with hibernation.…”

Self-ordering in the distribution of limpets: The role of previous occupants

“…from predation; Coleman et al, 2004a) or infochemicals via dissolved or surface-bound cues (Hay, 2009). In addition to containing cues about identity (Funke, 1968;Shaheen et al, 2005), which are important for predator-prey relationships or social networks, surface-bound chemical cues such as mucous trails laid by molluscs or stationary mucus to facilitate attachment can contain information on many other aspects of the emitting organism's biology (Davies and Hawkins, 1998;Ng et al, 2013). For molluscs such as limpets, perception of their chemical environment occurs through chemosensory apparatus on their external membranes (Croll, 1983) and via ingestion of biofilms/mucus (Davies and Hawkins, 1998), which themselves contain chemical cues (Croll, 1983).…”