Studies in the Physiology of Commensalism. IV. the Polynoid Genera Polynoë, Lepidasthenia and Harmothoe

Abstract

The host-response of the polynoid Polynoë scolopendrina Savigny, commensal with the terebellid Polymnia nebulosa (Montagu), is relatively specific within the family Terebellidae.Evidence is presented that an unstable or closely bound attractant is present on the outside of the host and perhaps in tube material, but apparently absent in the mucus secreted by the host. Efforts to demonstrate its presence in ground-up whole host resulted in failure.The polynoid Lepidasthenia argus Hodgson demonstrates a similar specificity of response to its host Amphitrite edwardsi Quatrefages.The polynoid Harmothoë spinifera Ehlers, commensal with Amphitrite gracilis Grube, responds to the alternate host Polycirrus caliendrum Claparede as strongly as to its own host, and more strongly than to other species of Amphitrite. Likewise, Polynoë scolopendrina, commensal with Polymnia, responds with greater intensity to the alternate host, the eunicid Lysidice ninetta Audouin and Milne-Edwards, than to any non-host terebellid. This behaviour may be i terpreted as evidence that the specificity of at least some single commensal species for hosts which are not closely related to each other may depend upon the production of similar attractants by these hosts.The responses of three commensal populations of Harmothoe lunulata (Delle Chiaje), commensal respectively with the ophiuroid Acrocnida brachiata (Montagu), the holothurian Leptosynapta inhaerens (O. F. Miiller), and the terebellid Amphitrite johnstoni Malmgren were tested against seven alternate hosts. Each gave maximum response to its own host. However, the population from Acrocnida responded as strongly to Leptosynapta as to its own host, while giving no responses at all to any of the other five.

Ecological adaptations and commensal evolution of the Polynoidae (Polychaeta) in the Southwest Indian Ocean Ridge: A phylogenetic approach

“…Interestingly, this species is only able to recognise its starfish host when adjacent to it (Davenport, 1953a), which is obviously adequate for shallow waters but not for the deep sea, where the generally low abundances and large distances between suitable habitats tend to reduce the probability of meeting the symbiont with its potential hosts. Polynoe scolopendrina was more selective in choosing the host species than A. squamosa (Davenport, 1953b). However, these conclusions proved to be controversial and more observations are required as each commensal species population can have different prevalence also affected by bathymetric, spatial and temporal variability (Martin and Britayev, 1998).…”

Biology of a “babysitting” symbiosis in brittle stars: analysis of the interactions between Ophiomastix venosa and Ophiocoma scolopendrina

“…It is well known that echinoderm hosts attract various types of symbionts thanks to stimuli mediated by water currents; for example, symbiotic crabs (Eeckhaut et al 2000) and shrimps (Vanden Spiegel et al 1998) are chemically attracted by crinoid hosts. Odor‐mediated host recognition was also observed in (1) polychaetes living either on asteroids or holothuroids (Davenport 1950, 1953a, b; Davenport & Hickock 1951; Dimock & Davenport 1971), (2) bivalves (Gage 1966), gastropods (Vaïntiligon et al 2004), shrimp (Ache & Davenport 1972), and crabs (Gray et al 1968) associated with echinoids, and (3) fish living with holothuroids (Van Meter & Ache 1974). Such odor‐mediated host recognition was not known in any symbiosis involving ophiuroids as hosts.…”

Further Studies in the Behavior of Commensal Polychaetes

“…As an example of the first category which exhibits precise response we have Arctonoc fragilis and its behavior in relation to Erastcrias, Orthasterias and Solaster. But there are also species in which populations from one host may give a similar precise response to some, but not necessarily all, alternate hosts, regardless of the absence of any taxonomic affinity between the hosts to which they do respond (Hannothoc lunulata from the brittle-star Acrocnida brachiata vs. its host and the alternate eunicid Lycidicc ninetta Davenport, 1953b). Among such species of diverse host habit there may be a population occurring on one of the array of hosts which responds to its host alone, in spite of the fact that other populations of the same species respond to several alternates (Hannothoc lunulata from Lcptosynapta inhacrens).…”

“…To date a number of studies have been made on the response specificity of commensal polychaetes (Davenport, 1950(Davenport, , 1953a(Davenport, , 1953bDavenport and Hickok, 1951 ;Bartel and Davenport, 1956). In these studies a number of techniques to discern the presence of chemical responses to host have been employed.…”