On the associations between Haplosyllis (Polychaeta, Syllidae) and gorgonians (Cnidaria, Octocorallaria), with the description of a new species

Abstract

The present paper includes a morphological, ecological and biological updating of the three gorgonian associated species of Haplosyllis (Polychaeta, Syllidae) known to date: H. chamaeleon (symbiont with Paramuricea clavata in the Mediterranean), H. anthogorgicola (symbiont with Anthogorgia bocki in the Japanese seas) and H. villogorgicola , a new species living symbiotically with Villogorgia bebrycoides which is only known from Tenerife (Canary Islands, Eastern Central Atlantic). The new species is described on the basis of ecological, morphological, morphometric and statistical analysis of relevant characteristics. Each host colony harboured about 15 pale‐yellowish worms, whose cryptic colouration mimicked that of the host. They occurred either on the host branches or partly hidden inside cavities formed by the fusion of two branches. The new species is characterized by the presence of simple chaetae with clearly bidentate tips all along the body, the presence of gland pore aggregates distributed in two lateral rows and two ventral patches on each palp and the absence of ciliary tufts on the pharyngeal papillae. H. villogorgicola sp. nov. is closely related to H. chamaeleon . Thus, it is compared with two populations of this species collected in the north‐west and south‐west Mediterranean. Stolons of H. chamaeleon are re‐described as tetracerous and a peculiar posterior end regeneration process occurring in adult worms during the stolon formation is described. H. anthogorgicola is also re‐described, with particular emphasis on its appendage and chaetal arrangements. The main features of the three associations are discussed in light of the current knowledge on symbiotic polychaetes, particularly cnidarian‐associated syllids. © 2002 The Linnean Society of London, Biological Journal of the Linnean Society , 2002, 77, 455–477.

Symbiotic association between Solanderia secunda (Cnidaria, Hydrozoa, Solanderiidae) and Medioantenna variopinta sp. nov. (Annelida, Polychaeta, Polynoidae) from North Sulawesi (Indonesia)

“…More than 300 polychaete species are known to be involved in different types of symbiotic relationships with other marine invertebrates which consequently developing morphological, behavioral, physiological or reproductive adaptations to their particular modes of life (Martin and Britayev 1998;Martin et al 2002). In monoxenous species, it often happens that the shape of some symbiont appendages perfectly mimics a relevant morphological characteristic of the host.…”

“…Some sponge-associated syllids feed on host tissues showing different colors that mimic their particular host (Pawlik 1983;Magnino and Gaino 1998). Among gorgonian-associated syllids, in turn, either feeding on the same food as the host, kleptoparasitism (i.e., stealing food from the gastral cavities of the host polyps) and/or co-evolution seems to be the reason for that mimicry (Martin et al 2002). However, syllids and scale-worms differ in their feeding behavior, the former suck food by means of their pharynx and their muscular proventricle, while the latter bite their prey with the help of their four powerful parrot's beak-like jaws.…”

“…For instance, the swollen dorsal cirri of the scale-worm Asterophylia carlae mimic the ambulacral feet of its host starfishes (Hanley 1989;Martin and Britayev 1998). Also, the whole body may display camouflage colorings exactly matching the host color such as those of the syllids Haplosyllis chamaeleon and H. villogorgicola and their respective gorgonian hosts (Laubier 1960(Laubier , 1968Martin et al 2002), or Alcyonosyllis phili and its alcyonacean host (Glasby and Watson 2001). In particular, it must be pointed out that A. phili has a color pattern which closely resembles that of M. variopinta sp.…”

Diversity, distribution and ecology of the family Syllidae (Annelida) in the Portuguese coast (Western Iberian Peninsula)

“…Some species were recorded for deeper waters compared to San Martín (2003) Syllis mercedesae was in this study sometimes found in gastropod shells, in symbiosis with a bivalve (Montacuta phascolionis) and a sipunculid (Phascolion (Phascolion) strombus strombus). A symbiotic mode of life is known for nearly 20 Syllid species, mostly with decapods, cnidarians and sponges (López et al 2001;Martin and Britayev 1998;Martin et al 2002). Symbiotic species have developed morphological adaptations, such as the simplification of chaetae, camouflage coloring or particular behavior (e.g., short-distance host recognition; Martin et al 2002).…”

“…A symbiotic mode of life is known for nearly 20 Syllid species, mostly with decapods, cnidarians and sponges (López et al 2001;Martin and Britayev 1998;Martin et al 2002). Symbiotic species have developed morphological adaptations, such as the simplification of chaetae, camouflage coloring or particular behavior (e.g., short-distance host recognition; Martin et al 2002). Among the genus Syllis, only S. armillaris, S. cornuta Rathke, 1843, S. gracilis, S. onkylochaeta Hartmann-Schröder, 1991 andS.…”