Species2000 Classification

Streptosyllis hainanensis Ding & Westheide 1994

Depth range:

shallow waters

Etymology:

Named after the locus typicus.

Habitat:

sand patch in dead coral reef

Source of description:

after Ding Z, Westheide W. 1994. Two new interstitial Streptosyllis species from South China (Polychaeta: Syllidae)

Source of Images:

Ding Z, Westheide W. 1994. Two new interstitial Streptosyllis species from South China (Polychaeta: Syllidae)

Species description:

Streptosyllis hainanensis, anterior part

Body slender and fragile, almost transparent, dorsally convex, ventrally flattened. Prostomium rounded anteriorly, straight posteriorly. Two pairs of eyes with lenses, in trapezoidal arrangement. Antennae slightly wrinkled. Median antenna inserted between eyes, lateral ones a little longer than half the length of the median antenna, inserted near anterior margin. Palps large, anteriorly rounded, fused at base. Peristomium bears two pairs of smooth tentacular cirri, dorsal ones slightly longer than ventral ones. Band of cilia behind tentacular cirri. Parapodia of chaetigers 2-5 large and distally truncated, remaining parapodia conical ans smaller. Dorsal cirri of 3 first chaetigers filiform, pseudoarticulated or articulated. From chaetiger 4, dorsal cirri articulated with 4-5 articles with glandular inclusions.

Streptosyllis hainanensis, parapod, chaetiger 22

From chaetiger 13 a bundle of notopodial (epitokous?) capillary chaetae present in each parapod. Ventral cirri digitiform, longer than parapodial lobe. Cilia at bases of dorsal and ventral cirri.

Streptosyllis hainanensis, aciculae, anterior parapodia

Chaetigers 2-5 with enlarged aciculae and chaetae. Aciculae distally knobbed, about twice as large as in remaining chaetigers.

Streptsyllis hainanensis, dorsal simple chaetae

Dorsal simple chaeta thick, curved, with subdistal serrations.

Streptsyllis hainanensis, compound chaetae, chaetiger 5

6-8 unidentate compound falcigers with short, serrated blades and bifid shafts in anterior chaetigers.

Remaining chaetigers with slender chaetae and aciculae. Aciculae distally sharply bent.Simple

dorsal chaeta slightly curved, with subdistal serration and hooded tip.

Streptosyllis hainanensis, compound chaetae, chaetiger 22

One to two compound falcigers with long blades and five to six falcigers with short blades. Blades serrated, with large serrations at blade and fine serrations distally, tip sharply hooked, shafts bifid.

Pharynx unarmed, proventriculum from middle of chaetiger 5 to chaetiger 9, with 40 muscular rows. Coelom with sperm from chaetiger 10.

Taxonomic Remarks:

S. hainanensis is most closely related to S. latipalpa , both species have large, dorsally visible palps and enlarged aciculae in chaetigers 2-5. It differs from this species by having two pairs of eyes, glandular structures in the dorsal cirri and unidentate compound chaetae. S. hainanensis is also related to S. baolingi , S. biarticulata, S. magnapalpa and S. varians, all these have large, dorsally visible palps. However, all these species differ in the number and arrangement of chaetigers with enlarged aciculae.

S. arenae , S. cryptopalpa , S.verrilli and S. websteri also have enlarged aciculae in chaetigers 2-5, however they all have small palps not visible from above.

Type locality:

Hainan Island, South China

Type taxon:

SpeciesAuthor:

Streptosyllis hainanensis Ding and Westheide 1994

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Species2000 Classification

Streptosyllis hainanensis