BIHAREAN BIOLOGIST 10 (1): 8-11 ©Biharean Biologist, Oradea, Romania, 2016 Article No.: e151205 http://biozoojournals.ro/bihbiol/index.html

First record of the Family Echinoderidae Zelinka, 1894 (Kinorhyncha: Cyclorhagida) from Turkish Marine Waters

Serdar SÖNMEZ1,*, Nuran Özlem KÖROĞLU2 and Süphan KARAYTUĞ3

1. Adıyaman University, Faculty of Science and Letters, Department of Biology, 02040 Adıyaman, Turkey. 2. Mersin University Silifke Vocational School, 33940, Silifke, Mersin, Turkey.

3. Mersin University, Faculty of Arts and Science, Department of Biology, 33343 Mersin, Turkey. *Corresponding author, S. Sönmez, E-mail: sonmezserdar@gmail.com

Received: 23. January 2015 / Accepted: 10. May 2015 / Available online: 01. June 2016 / Printed: June 2016

Abstract. During a survey along the Aegean Coast of Turkey, two kinorhynch species which are closely related to Echinoderes gerardi and Echinoderes bispinosus were encountered. The two species are photographed with light microscopy and described briefly. Although the phylum as well as the genus have been known more than 150 years from the Mediterranean Sea, the presence of species of the family Echinoderidae at Turkey have not been reported previously. Therefore this is the first record of the family Echinoderidae from Turkish marine waters and also the first record of the Phylum Kinorhyncha from the Aegean Sea Coast of Turkey.

Key words: Meiofauna, intertidal, Mediterranean Sea, Aegean Sea, distribution.

Introduction The phylum Kinorhyncha is one of the three phyla of Scali-dophora which is defined by the following characters: (i) having a moulted chitinous cuticle, (ii) rings of scalids on the introvert, (iii) flosculi, and (iv) two rings of introvert retrac-tors attached through the collar-shaped brain (Heiner and Kristensen 2005). Members of the phylum are strictly ma-rine, benthic, small (102µm-1100 µm) and segmented meta-zoans that inhabit mostly in muddy sediments of the oceans and inland seas (Sørensen and Pardos 2008). The phylum is considered to have a world-wide distribution from polar to tropical regions, and from the intertidal to abyssal depths, and comprises about 200 species (Yamasaki et al. 2014) which are distributed in 23 genera (Dal Zotto et al. 2013, Sørensen 2013, Sánchez et al. 2014).

During a survey exploring the harpacticoid copepods along the Aegean Coast of Turkey, two kinorhynch species which are closely related to Echinoderes gerardi Higgins, 1978 and Echinoderes bispinosus Higgins, 1982 were encountered in phytal and interstitial samples. Although the phylum as well as the genus has been known for more than 150 years from the Mediterranean Sea (Higgins 1978), the presence of the kinorhynch species at Mediterranean and Aegean Coasts of Turkey have not been reported previously. The only record of the phylum is that of Băcescu (1961), who reported Pycno-phyes communis Zelinka, 1908 (Pycnophyidae) from the pre-Bosphorus region of Black Sea. Therefore this is the first re-cord of the genus Echinoderes as well as the family Echinode-ridae from Turkish marine waters. Material and methods Interstitial and phytal samples were collected from the intertidal zone of Aegean Sea Coast of Turkey as described in Alper et al (2010) and immediately fixed in a 4% formalin solution. Kinorhynchs were separated from the detritus by a Pasteur pipette under an Olympus SZX-16 stereo microscope. Specimens were dehydrated through a graded series of glycerine and mounted in 100% glycerine. Broken cover glass pieces were added between slide and cover glass to pre-vent animal being compressed, and to facilitate rotation and manipu-lation. The specimens were examined and photographed with a DIC

attached Olympus BX-50 microscope which is equipped with an Olympus E-330 camera. Focus stacking method was used to obtain final images with greater depth of field as described in Sönmez et al. (2014). Identifications were made with the aid of Sørensen and Par-dos (2008), Adrianov et al. (2002) and the original descriptions (Hig-gins 1978; 1982). Specimens were deposited in the collection of Mersin University Biology Department.

Sørensen and Pardos (2008) was followed for the measurements and the terminology. Abbreviations used in the text and figures are: la for lateral accessory spine; ltas for lateral terminal accessory spine; lts for lateral terminal spine; lv for lateroventral spine; md4-md7 for middorsal spine on the trunk segments 4-7; MSW for maximum sternal width; s1-s11 for the trunk segments 1-11; SW for standart width; TL for trunk length and vl for ventrolateral spine. Results Order: Cyclorhagida (Zelinka, 1896) Higgins, 1964 Family: Echinoderidae Zelinka, 1894 Genus: Echinoderes Claparède, 1863 Echinoderes aff. gerardi Higgins, 1978 Material examined: 1 ♀ from algal washings, intertidal zone, Doğanbey Beach, İzmir, Turkey, 38˚ 03’ 47.5” N; 26˚ 54’ 10.3” E, 25.10.2012.

Description: Adult female with head, neck and 11 trunk segments (Fig. 1-2). TL 261 µm, MSW 68 µm at 8th segment, SW 63 µm. Basal plates of subventral trichoscalids broader than long, centered above subventral placids, basal plates of subdorsal trichoscalids almost squarish, centered above subdorsal placids. Neck with 16 placids, equal in length (16 µm), medioventral placid widest, slightly tapering to the an-terior margin, 14 µm at base, 10 µm at top. Trunk segment surfaces covered with evenly distributed fine hairs.

S1 closed cuticular ring, with one sensory spot in mid-dorsal position, posterior margin without pectinate fringe. S2 closed cuticular ring, posteroventral margin with pecti-nate fringe, bears one middorsal sensory spot and a pair of naked ventrolateral spines (24 µm). S3-11 with one tergal and two sternal plates. S3 bears one middorsal glandular cell outlets type 1 (gco1). S4-7 with one short middorsal spine (md4 6.5 µm, md5 9.5 µm, md6 11.3 µm, md7 12.7 µm) and

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Figure 1. Echinoderes aff. gerardi, female, A) ventral overview; B) s3-8, dorsal view, white circles indicate the md4-7, black arrows indicate the sensory spots; C) lateral overview.

 

Figure 2. Echinoderes aff. gerardi, female, A) s1, 2, ventral view; B) s1, 2 , dorsal view; C) s9-11, ventral view; D) s10-11, dorsal view.

two subdorsal sensory spots. S5-9 bear a pair of lateroventral spines. S8 with lateral accessory spine. S9 bears a pair of sen-sory spots in paradorsal positions. S11 with tergal extension as in figure 2C-D, bearing a pair of lts (180 µm) and ltas (55 µm). Echinoderes aff. bispinosus Higgins, 1982 Material examined: 1 ♀ from interstitial sample, İmren

Beach, Mordoğan, İzmir, Turkey, 38˚ 28’ 20.3” N; 26˚ 36’ 40.9” E, 27.10.2012.

Description: Adult female with head, neck and 11 trunk segments (Fig 3-4). TL 290 µm, MSW 53 µm at 7th segment, SW 46 µm. Neck with 16 placids, equal in length 12,5 µm, medioventral plate widest, slightly tapering to the anterior margin, 11 µm at base, 6 µm at top. Trunk segment surfaces ornamented with patches of fine hairs with distinctive bases,

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Figure 3. Echinoderes aff. bispinosus, female, overview, A) lateral , B) ventral.

Figure 4. Echinoderes aff. bispinosus, female, dorsal view A) s1-4; B) s4-6; C) s9; D) s11; white circles indicate sensory spots, black arrows indicate md4 and md6.

posterior margins covered with pectinate fringes. S1 closed cuticular ring, with one sensory spot in mid-

dorsal position. S2 closed cuticular ring, bearing one mid-dorsal gco1 and a pair of tubes (16 µm) in lateroventral posi-tion. S3-11 with one tergal and two sternal plates. S3 bears one middorsal sensory spot. S4 with one middorsal spine (19,2 µm) and a pair of sensory spots located in paradorsal position. S5 with a pair of lateroventral tubes (17 µm) and a sensory spot at middorsal position. S6 bears a pair of lateroventral spines (19.3 µm), a pair of sensory spots located in paradorsal position and a middorsal spine (21 µm). S7 with a pair of lateroventral spines (20 µm), and a sensory spot in middorsal position. S8 with a pair of lateroventral spines (21 µm) and a pair of sensory spots located in para-dorsal position. S9 bears a pair of lateroventral spine (27.5 µm) and a pair of sensory spots located in paradorsal posi-tion. S10 with a sensory spot in middorsal position. S11 with

a tergal extension as in figure 4D, bears a pair of lts (164 µm) and a pair of ltas (36 µm). Discussion E. gerardi was originally described by Higgins (1978) from the pore chambers of a sponge (Tethya aurantium (Pall.)) which was collected from the Gulf of Tunis. When compared with the original description, our specimen is very similar to E. gerardi in all other aspects except the number of middorsal spines. Our specimen has 4 md (md4-7) while the original description there is 5 (md4-8). Although it is a very impor-tant character that can define a species, the paucity of the material (only 1 female) restricts us to give the decision that if the lack of the middorsal spine on the segment 8 is a con-sistent character within the population.

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Figure 5. Echinoderes aff. bispinosus, female, ventral view, A) s1-5; B) s2-6; C) s6-10; D) s8-11. Black arrows indicate lateral accessory spines.

The one and only record of E. bispinosus is from Ber-muda, North Atlantic, where it was originally described. Then Sorensen (2014) redescribed the species from the holo-type. Although our specimen is generally in agreement with the original description and the redescription of Sorensen (2014), we could not observe the gco2’s at the segment 2. But we believe that it is very hard to justify a new species with this subtle difference which is obtained from the observation of only one individual with the light microscopy.

It is well known that kinorhynchs usually inhabit the uppermost 2-3 cm of the sediments due to the oxygen avail-ability (Sørensen and Pardos 2008). As the sampling method used in this study was not designed to collect kinorhynchs, we could not get enough number of individuals for detailed examination such as SEM. Therefore we conclude that inten-sive sampling with proper methods is needed to reveal the true diversity of kinorhynchs of Turkish marine waters. References Adrianov, A.V., Murakami, C., Shirayama, Y. (2002): Echinoderes aureus n. sp.

(Kinorhyncha: Cyclorhagida) from Tanabe Bay (Honshu Island), Japan, with a key to the genus Echinoderes. Species Diversity: an International Journal for Taxonomy, Systematics, Speciation, Biogeography, and Life History Research of Animals 7: 47-66.

Alper, A., Karaytuğ, S., Sak, S. (2010): Interstitial and Phytal Harpacticoida (Crustacea: Copepoda) inhabiting the Mediolittoral Zone of the Datça-Bozburun Peninsulas (Muğla, Turkey). SDU Journal of Science 5: 16-28.

Băcescu, M. (1961): Le role des iles dans la dispersion récente des espèces indo-pacifiques en Méditerranée occidentale et quelques observations sur la faune marine de L’ile des serpents, en comparaison avec celle peuplants les parages prébosphoriques de la Mer Noire V., Le Peuplement des Iles Méditerraneennes et la Problème de L’insularité, Banyuls-sur-Mer.

Dal Zotto, M., Di Domenico, M., Garraffoni, A., Sørensen, M.V. (2013): Franciscideres gen. nov.–a new, highly aberrant kinorhynch genus from Brazil, with an analysis of its phylogenetic position. Systematics and Biodiversity 11: 303-321.

Heiner, I., Kristensen, R.M. (2005): Two new species of the genus Pliciloricus (Loricifera, Pliciloricidae) from the Faroe Bank, North Atlantic. Zoologischer Anzeiger 243: 121-138.

Higgins, R.P. (1978) Echinoderes gerardi n. sp. and E. riedli (Kinorhyncha) from the Gulf of Tunis. Transactions of the American Microscopical Society 97: 171-180.

Higgins, R.P. (1982): Three new species of Kinorhyncha from Bermuda. Transactions of the American Microscopical Society 101: 305-316.

Sanchez, N., Pardos, F., Sørensen, M.V. (2014): A new kinorhynch genus, Mixtophyes (Kinorhyncha: Homalorhagida), from the Guinea Basin deep-sea, with new data on the family Neocentrophyidae. Helgolang Marine Research 68: 221-239.

Sørensen, M.V. (2013): Phylum Kinorhyncha. In: Zhang, Z.-Q.(Ed.) Animal Biodiversity: An Outline of Higher-level Classification and Survey of Taxonomic Richness (Addenda 2013). Zootaxa 3703: 63-66.

Sørensen, M.V. (2014): First account of echinoderid kinorhynchs from Brazil, with the description of three new species. Marine Biodiversity, 44:251-274.

Sørensen, M.V., Pardos, F. (2008): Kinorhynch systematics and biology-an introduction to the study of kinorhynchs, inclusive identification keys to the genera. Meiofauna Marina 16: 21-73.

Sönmez, S., Sak, S., Karaytuğ, S. (2014): Marine interstitial and phytal Miraciidae Dana, 1846 (Crustacea: Copepoda: Harpacticoida) inhabiting along the mediolittoral zone of Turkish coasts. Journal of Anatolian Natural Sciences 5: 52-87.

Yamasaki, H., Hiruta, S.F., Kajihara, H., Dick, M.H. (2014): Two Kinorhynch Species (Cyclorhagida, Echinoderidae, Echinoderes) Show Different Distribution Patterns Across Tsugaru Strait, Northern Japan. Zoological Science 31: 421-429.