Sphaerosyllis levantina

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Sphaerosyllis levantina
ZooKeys-150-327-g001.jpg
Sphaerosyllis levantina holotype, dorsal view
Scientific classification
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S. levantina
Binomial name
Sphaerosyllis levantina
Faulwetter et al., 2011

Sphaerosyllis levantina is a species belonging to the phylum Annelida, a group known as the segmented worms. [1] It was first described from Haifa Bay in the eastern Mediterranean. It is similar to Sphaerosyllis hystrix , and is thought to show a cosmopolitan distribution. Its name derives from its type locality (Levantine Basin), levantina being the feminine form of a Neo-Latin adjective meaning "pertaining to the region where the sun raises"; the adjective is feminine to agree with the feminine genus name, Syllis being a river nymph in Greek mythology. [1]

Contents

While Faulwetter et al. researched the soft bottom benthos of Haifa Bay, several individuals of the Sphaerosyllis exhibited features which did not correspond to any known Sphaerosyllis species. These characteristics were: falcigers with prominent serration and with a subdistal spine present in all chaetigers; a subdistal spine on the blades of some of its falcigers (also found in S. hystrix and S. boeroi). The authors then re-examined material of Sphaerosyllis hystrix from previous finds, which revealed some individuals possessed a subdistal spine on the blades of anterior falcigers and also in posterior chaetigers. To clarify the relationship between the new specimens and the 2 described species possessing falcigers with a subdistal spine, the scientists conducted a morphometric analysis. [1]

Description

The animal counts with 25 chaetigers over a length of 1.9 millimetres (0.075 in) with palps but without anal cirri. Its width at its sixth chaetiger is 250µm without parapodia. It has a small and thin body, widest at its proventricle. It shows irregular dorsal papillation on its anterior chaetigers, while its ventrum does not show papillation. Its prostomium is wider than long, with 4 coalescent lensed eyes arranged trapezoidally; anterior eyespots are absent. It counts with pyriform antennae with bulbous bases and elongated tips, its median antenna measuring 40 µm long, while lateral ones measure 33 µm, which is longer than its prostomium and palps together. Its median antenna is inserted between its anterior pair of eyes, the lateral ones attached on the anterior margin of its prostomium. The animal's palps are ventrally-directed, fused along their length and with a dorsal notch and few small papillae. [1]

Its peristomium shows a dorsal fold partly covering the prostomium. It counts with one pair of tentacular cirri, which are shaped like the antennae but are shorter. Its second chaetiger lacks dorsal cirri but has a large papilla instead. The dorsal cirri are shaped similarly to the tentacular cirri. Its ventral cirri are conical and half as long as its parapodial lobe. Its anterior parapodia possess 4 to 5 (in rare cases 6) falcigers per fascicle; its blades are thin and unidentate, with their lengths showing dorso-ventral gradation, dorsal ones measuring a maximum of 14 µm, while ventral ones 10 µm. Posterior dorsal blades have a similar length 13 µm. [1]

S. levantina's ventral simple chaeta on the posterior chaetigers are sigmoid and smooth. Anteriorly, the parapodium exhibit two aciculae, one distally bent at a right angle, with an acuminate tip, the other being straight and blunt; posterior parapodium shows only one acicula as previously described. Its pharynx occupies three chaetigers, with a width spanning more than ¾ of the width of the proventricle. Its pharyngeal tooth is located on its anterior margin, surrounded by a crown of soft papillae. The proventricle possesses 15 to 17 muscle cell rows. The pygidium is papillated, with two anal cirri twice as long as the dorsal cirri. [1]

Sphaerosyllis levantina and Sphaerosyllis minima are alike, by having serrated blades of falcigers throughout the body. S. minima, however has a stronger dorso-ventral gradation of the falcigers' blades. Sphaerosyllis capensis , Sphaerosyllis taylori , and Sphaerosyllis sandrae also show similarities with S. levantina, especially with regards to the shape and serration of the falcigers' blades, but S. capensis has all antennae positioned in line, and S. taylori shows no dorso-ventral gradation of the falciger blade length, while S. sandrae has smooth falcigerous blades posteriorly and parapodial glands with hyaline material. All of these species differ from Sphaerosyllis levantina by lacking a subdistal spine on the falcigers' blades. Three species of Sphaerosyllis are known to possess this spine: S. hystrix, Sphaerosyllis parabulbosa and S. boeroi. S. parabulbosa differs from S. levantina by carrying minuscule dorsal cirri and antennae, by the exhibiting a subdistal spine only the posterior falcigers' blades and by the smooth blades of its posterior falcigers. S. boeroi, in turn, differs from S. levantina in having significantly longer falciger blades, which simultaneously show more pronounced dorso-ventral gradation. S. hystrix can be distinguished from S. levantina by showing smooth or finely serrated posterior falcigers, even when the spine is present. Concomitantly, blades of the dorsalmost falcigers show anteroposterior gradation in length in hystrix, whereas in levantina they are of similar length throughout its body. S. hystrix also possesses a considerably narrower pharynx. [1]

Distribution

S. levantina was found in fine to medium sands in Haifa Bay, at a depth of 10.5 metres (34 ft). Its distribution includes the Israeli coast (Levantine Basin). [1]

Related Research Articles

<span class="mw-page-title-main">Prostomium</span>

The prostomium is the cephalized first body segment in an annelid worm's body at the anterior end. It is in front of the mouth, being usually a small shelf- or lip-like extension over the dorsal side of the mouth. The prostomium together with the peristomium, which includes the mouth and pharynx, make up the annelid head.

<span class="mw-page-title-main">Phyllodocida</span> Order of annelid worms

Phyllodocida is an order of polychaete worms in the subclass Aciculata. These worms are mostly marine, though some are found in brackish water. Most are active benthic creatures, moving over the surface or burrowing in sediments, or living in cracks and crevices in bedrock. A few construct tubes in which they live and some are pelagic, swimming through the water column. There are estimated to be more than 4,600 accepted species in the order.

Prosphaerosyllis battiri is a species belonging to the phylum Annelida, a group known as the segmented worms. The species name comes from an Aboriginal word, battiri, meaning "rough". Prosphaerosyllis battiri is a species characterized by having only partially fused palps, an unretracted prostomium on its peristomium or showing only slight retraction, the shape of its dorsal cirri and its arrangement of papillae, being numerous anteriorly while less numerous posteriorly. It resembles Prosphaerosyllis semiverrucosa, but its arrangement of dorsal papillae is reversed.

Salvatoria pilkena is a species belonging to the phylum Annelida, a group known as the segmented worms. The species name comes from an Aboriginal word, pilkena, meaning "different", due to its characteristic features. Salvatoria pilkena belongs to a reduced group of species that possess rugose dorsal cirri, contrary to the typical spindle-shaped cirri found in its genus. It also lacks dorsal cirri on chaetiger 2. It resembles Salvatoria swedmarki and S. celiae, differing from pilkena in that the latter has significantly longer proventricles, while its compound chaetae are short and unidentate. At the same time, S. opisthodentata has a similar body and compound chaetae but appears to possess dorsal cirri on its chaetiger 2.

Salvatoria koorineclavata is a species belonging to the phylum Annelida, a group known as the segmented worms. A related species in Australia has been described as Brania clavata and subsequently as Salvatoria clavata. While similar, the Australian species has a longer pharynx and proventricle; at the same time, blades of chaetae are present in the Australian species, with longer and upwards curved spines, which are straight in S. clavata; its pharyngeal tooth is located more anteriorly than in S. clavata. Other global species, like those in the genus Brania, are also similar to S. koorineclavata. Salvatoria californiensis has similar chaetae, with shorter spines and less developed teeth. Its acicula lacks a defined acute tip, and the proventricle is quite shorter, running through 5 segments in S. koorineclavata, with fewer rows of muscle cells. The species name comes from an Aboriginal word, Koorine, meaning "daughter", due to the similarity of the Australian species to the European species of S. clavata.

Erinaceusyllis, previously known as Sphaerosyllis, is a genus belonging to the phylum Annelida, a group known as the segmented worms. This genus consists of several species that were previously described as Sphaerosyllis and as Sphaerosyllis erinaceus sub-species, differing by the compound chaetae.

Erinaceusyllis ettiennei is a species belonging to the phylum Annelida, a group known as the segmented worms. E. ettiennei is characterized by its compound chaetae with slender and thin blades, which are curved as a sabre. The most similar species is Erinaceusyllis serratosetosa, but is differentiated by the size of its body and the compound chaetae, which have long and curved marginal spines on its long blades in E. serratosetosa. The species is named in honour of Ettienne Fourie.

Erinaceusyllis cirripapillata is a species belonging to the phylum Annelida, a group known as the segmented worms. E. cirripapillata is characterized by its papillae on its dorsal cirri, one of them being distinctively mushroom-shaped. No species of this genus or Sphaerosyllisis is known to possess this particular kind of papillae. The name of the species refers to these same papillae.

Erinaceusyllis hartmannschroederae is a species belonging to the phylum Annelida, a group known as the segmented worms. This species was previously described in Australia as Sphaerosyllis erinaceus and S. erinaceus erinaceus, a species distributed throughout the globe. These species appear to be a species complex. Previous descriptions stated that the two aforementioned species possess compound chaetae blades which are long and slender. Several subspecies of S. erinaceus were described on the basis of differences in shapes and sizes of their compound chaetae; such differences are enough to consider them as distinct species. The species is named in honour of Gesa Hartmann-Schröder, an expert on syllid species.

Erinaceusyllis kathrynae is a species belonging to the phylum Annelida, a group known as the segmented worms. E. kathrynaen is similar to E. cirripapillata, but lacks characteristic papillae on its cirri. At the same time, Sphaerosyllis perspicax - which according to San Martín (2005) could belong to the genus Erinaceusyllis - is also similar, but its anterior dorsal cirri are inflated at their bases; the eyes and antennae are arranged linearly, and the palps are fused along their length. This species is named in honour of Kathryn Attwood of the Australian Museum.

Sphaerosyllis bardukaciculata is a species belonging to the phylum Annelida, a group known as the segmented worms. Sphaerosyllis bardukaciculatan is similar to Sphaerosyllis aciculata from Florida; its chaetae are almost identical; the former, however, differs by having longer antennae and anal cirri, as well as parapodial glands with granular material. The animal's name is derived from the Aboriginal word barduk, meaning "near", alluding to the aforementioned likeness with S. aciculata.

Sphaerosyllis voluntariorum is a species belonging to the phylum Annelida, a group known as the segmented worms. This species is closely related to Sphaerosyllis bifurcata, Sphaerosyllis bifurcatoides and Sphaerosyllis rotundipapillata, all endemic species to Australia, characterized by having large dorsal papillae, sometimes trilobed, and with shafts of compound chaetae distally bifid. S. voluntariorum is more densely papillated on its anterior segments and has a long subdistal spine on the ventral simple chaetae. This species' name alludes to the volunteers of the Marine Invertebrate section of The Australian Museum, who sorted specimens of syllids that led to the description of this animal.

Sphaerosyllis goorabantennata is a species belonging to the phylum Annelida, a group known as the segmented worms. Sphaerosyllis goorabantennata is distinct by its small size, small and unevenly distributed papillae, as well as by its particularly long antennae and tentacular cirri. Sphaerosyllis minima and S. minima magnapapillata are also small, but their antennae and tentacular cirri are significantly shorter, like its cogenerate species. The species' name is derived from the Aboriginal word gooraba, meaning "big", alluding to its long antennae.

Sphaerosyllis georgeharrisoni is a species belonging to the phylum Annelida, a group known as the segmented worms. Sphaerosyllis georgeharrisoni is distinct by its large parapodial glands with hyaline material; by its small size; short proventricle; a median antenna that is inserted posteriorly to the lateral antennae; as well as long pygidial papillae. Juveniles of S. hirsuta are very similar to this species. Sphaerosyllis pygipapillata has all of its antennae aligned, a smooth dorsum, while its pygidial papillae are longer and slender. The species' name honours George Harrison, musician who died prior to the species' describing article's publication.

Parapionosyllis winnunga is a species belonging to the phylum Annelida, a group known as the segmented worms. Parapionosyllis winnunga is characterized by the shape of the blades of its compound chaetae, which have a long subdistal spine, in turn much longer than in other cogenerate species. Its species name is derived from the Aboriginal word winnunga, meaning "small".

<i>Leucia</i> Genus of annelids


Leucia is a genus of marine polychaete worms belonging to the family Polynoidae, the scaleworms. Leucia contains 2 species, both found in the northern Atlantic Ocean. This genus is distinguished from the closely related genus Harmothoe by having sixteen pairs of elytra, as opposed to fifteen.

<i>Leucia nivea</i> Species of annelid worm

Leucia nivea is a species of polychaete worm, commonly known as a "scale worm", in the family Polynoidae. This species occurs in the northeastern Atlantic Ocean, the North Sea and the Mediterranean Sea.

Australonoe willani is a species of marine annelids in the family Polynoidae, and the sole member of the genus Australonoe, known only from the south-east Indian Ocean at Rottnest Island, Western Australia.

Bathynoe is a genus of marine annelids in the family Polynoidae. The genus includes 6 species, 5 of which occur in the Pacific Ocean while one occurs in the Atlantic Ocean. Bathynoe species have been recorded from depths of about 500 – 3000 m.

Eucranta is a genus of marine annelids in the family Polynoidae. The genus includes 5 species which are globally distributed from depths of about 40 to 600 m, mostly from high latitudes in the northern and southern hemispheres.

References

  1. 1 2 3 4 5 6 7 8 Faulwetter, Sarah; Chatzigeorgiou, Georgios; Galil, Bella S.; Nicolaidou, Artemis; Arvanitidis, Christos (2011). "Sphaerosyllis levantina sp. n. (Annelida) from the eastern Mediterranean, with notes on character variation in Sphaerosyllis hystrix Claparède, 1863". ZooKeys (150): 327–345. doi: 10.3897/zookeys.150.1877 . PMC   3234443 . PMID   22346561.

Further reading