Echinoderes sp.
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publication ID |
https://doi.org/ 10.3906/zoo-2108-20 |
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publication LSID |
lsid:zoobank.org:pub:D4BFE4E5-F4E6-4EBE-8762-A30D03769F28 |
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persistent identifier |
https://treatment.plazi.org/id/03F48798-0F63-9045-FD07-F941FE5DFBB8 |
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treatment provided by |
Felipe |
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scientific name |
Echinoderes sp. |
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3.4. Echinoderes sp.
Figures 7A–7E, 7G–7I View Figure 7
Material examined: A single male specimen collected from St. 9 (see Table 1 for station data). The specimen was mounted for LM, and deposited at NHMD under catalogue number NHMD-872893.
Notes on morphology: The single specimen was examined. Debris and the general condition of the specimen made it nearly impossible to observe sensory spots and glandular cell outlets type 1, but spines, tubes and glandular cell outlets type 2 were easily observed (see Table 4 for a summary).
The trunk (trunk length = 242 µm) is relatively slender, and narrows abruptly from segment 9 (MSW-7 = 50 µm; SW-10 = 40 µm) ( Figure 7A View Figure 7 ). Acicular spines are present in middorsal position on segment 4 ( MDS4 = 14 µm) ( Figures 7B and 7D View Figure 7 ), in lateroventral positions on segments 6 to 9 (LV6-7 = 13 µm; LV8-9 = 15 µm) ( Figures 7C and 7E View Figure 7 ), and as lateral terminal spines ( LTS = 137 µm). Tubes are present in ventrolateral positions on segment 2 (could not be measured), in lateroventral positions on segment 5, and in sublateral positions on segment 8 ( SLT = 14 µm) ( Figures 7C and 7E View Figure 7 ). Large glandular cell outlets type 2 are present in subdorsal and sublateral positions on segment 2 ( Figures 7B and 7C View Figure 7 ). Tergal extensions are long and slender, with a small tooth on the inferior margins, and long pointed tips ( Figure 7H View Figure 7 ). Dorsal and ventral pair of penile spines appear truncate and rather rigid ( Figures 7H–7I View Figure 7 ) .
The presence of a middorsal spine on segment 4 only makes Echinoderes sp. resemble another Turkish species, E. antalyaensis , but the two species differ at other important points. Most importantly, Echinoderes sp. has lateroventral spines on segments 6 to 9, whereas E. antalyaensis has such spines on segments 6 to 8 only. Furthermore, in E. antalyaensis tubes on segment 2 are lateroventral rather than ventrolateral, and on segment 8 they are lateral accessory rather than sublateral ( Yamasaki and Durucan, 2018). An additional conspicuous difference between the two species is the large glandular cell outlets type 2, which are present in Echinoderes sp. but lacking in E. antalyaensis . These outlets are so distinct that they could not have been overlooked in E. antalyaensis , and this is also well-documented in the description of the species ( Yamasaki and Durucan, 2018). Therefore, we do not consider Echinoderes sp. and E. antalyaensis to be conspecific.
Another, even closer species is E. charlotteae SØrensen, Herranz & Landers, 2016. The species was described from subtidal mud in the northern part of the Gulf of Mexico ( SØrensen et al., 2016). The spine and tube patterns in the two species are very similar, but with the same differences as described between Echinoderes sp. and E. antalyaensis . Furthermore, E. charlotteae has small laterodorsal tubes on segment 10, but such tubes are often difficult to observe in LM, and without SEM documentation we cannot for sure confirm their presence or absence in Echinoderes sp. Besides the similar spine/tube patterns, Echinoderes sp. and E. charlotteae share the presence of large glandular cell outlets type 2 in subdorsal and sublateral positions on segment 2. Trunk and spine lengths in Echinoderes sp. are furthermore within the ranges of E. charlotteae , and the conspicuous shape of the tergal extensions is very similar.
The numerous similarities between Echinoderes sp. and E. charlotteae obviously leaves us with the question whether they should be considered conspecific. For many years species of Echinoderes were all considered to show rather regional and limited distribution patterns, but recent studies have indicated that at least deep-sea species could have much wider, even cross-oceanic, distributions ( SØrensen et al., 2018, Yamasaki et al., 2018b, Cepeda et al., 2020, Grzelak et al. 2021). However, we still find conspecifity of Echinoderes sp. and E. charlotteae rather doubtful. First of all, we note the small differences in tube positions, i.e. ventrolateral tubes on segment 2 and sublateral tubes ( Figure 7E View Figure 7 ) on segment 8 in Echinoderes sp. versus lateroventral tubes on segment 2 and lateral accessory tubes ( Figure 7F View Figure 7 ) on segment 8 in E. charlotteae . Furthermore, we also note that Echinoderes sp. was collected from medium coarse sand at 8 m depth, whereas E. charlotteae was described from mud at 74 to 163 m. Kinorhynch species might be adapted to different habitats and depths, but we still consider this considerable difference in habitat to speak against conspecifity. Thus, given the limited information available, we would prefer to suggest that Echinoderes sp. represents a new species that shows close resemblance to E. charlotteae .
3.5. New records of Campyloderes vanhoeffeni Zelinka, 1913
Material examined: The species was quite abundant at St. 3/4 (see Table 1 for station data). Three females, five males and one juvenile were mounted for LM, and five females and five males for SEM. All specimens mounted for LM are deposited at NHMD under catalogue numbers NHMD-872944 to 872955, and all SEM specimens are stored in the reference collection of the first author .
Notes on taxonomy and distribution: Campyloderes is a small genus with only two described species, C. vanhoeffeni Zelinka, 1913 and C. macquariae Johnston, 1938 . Following strict alpha taxonomic thinking they should for now be considered as two distinct species, but practically they can be considered as synonymous, with C. macquariae as a junior synonym of C. vanhoeffeni . A comparison of the two species descriptions reveals that there are no significant morphological differences between the two species ( Zelinka, 1913, Johnston, 1938), and a formal synonymization of the two species only requires a reexamination of specimens from the two, rather remote, Subantarctic type localities. Since the morphology of the collected specimens fit both descriptions, as well as the much more recent morphological notes on C. cf. vanhoeffeni provided by Neuhaus (2004) and Neuhaus and SØrensen (2013), we will, in the following, refer to our specimens as C. vanhoeffeni .
(type 1 only partially mapped), tubes and spines arranged by series in Echinoderes sp. Abbreviations:
LV: lateroventral; MD: middorsal; ML: midlateral; PD: paradorsal; SD: subdorsal; SL: sublateral; VL:
ventrolateral; ac, acicular spine; gco1/2, glandular cell outlet type 1/2; lts, lateral terminal spine; pe,
penile spines; ss, sensory spot; tu, tube; (♂), male condition of sexually dimorphic character.
The species, or species complex, C. vanhoeffeni has been subject for intense studies by Neuhaus (2004), and Neuhaus and SØrensen (2013), who compared populations with a nearly global distribution. The specimens showed morphological variation in between the different populations, but always regarding inconspicuous details that made it difficult to determine if they represented sexual or developmental dimorphism, intraspecific variation, or signs of semicryptic speciation.
The specimens of C. vanhoeffeni collected at Balıkesir follow the general patterns for the species, as described by Neuhaus and SØrensen (2013). Besides the usual sexual dimorphism, the specimens did not show any variation suggesting adult, developmental dimorphism. However, more specimens, or sampling at different times of the year, might have revealed the occurrence of adult moulting.
Neuhaus and SØrensen (2013) stress the potentially global distribution of the species, by including specimens from the tropical Mid- and West Pacific, Northwest and East Atlantic, East and West Indian Ocean, Oceania and Korea. However, they do not include any Mediterranean specimens. So far, the only published Mediterranean records of C. vanhoeffeni are from the south- and southeast coast of Spain ( Sánchez et al., 2012). More recently, but still not published, Herranz and SØrensen collected the species from the Gulf of Naples in the Central Mediterranean, and with the current findings of C. vanhoeffeni from Turkey in the East Mediterranean, we have clear indications that the species most likely can be found throughout the Mediterranean Sea.
The species’ morphology is already well-documented (see Neuhaus (2004), and Neuhaus and SØrensen (2013)), thus we find it redundant to provide further photo documentation in the present contribution.
3.6. New observations and records of Cephalorhyncha flosculosa Yıldız et al., 2016
Figures 8A–8F View Figure 8
Material examined: The species was relatively abundant at two stations, St. 5 and St. 8, near Antalya (see Table 1 for station data). From the subtidal Station 5, six males and one juvenile were mounted for LM, whereas two females, five males and a juvenile were mounted for SEM. From the shallower Station 8, two females, four males and five juveniles were mounted for SEM. All LM specimens are deposited at NHMD under catalogue numbers NHMD-872940 to 872946, and all SEM specimens are stored in the reference collection of the first author .
Description: The morphology of the examined specimens generally followed the original species description by Yıldız et al. (2016), regarding tube- and spine patterns ( Figures 8A–8B, 8D–8E View Figure 8 ), composition of segment 2 ( Figure 8D View Figure 8 ), and the presence of small, midventral flosculi near the posterior segment margins ( Figure 8C View Figure 8 ). However, they also differed at two important points: Paradorsal sensory spots were clearly missing on segments 4 and 5 ( Figure 8E View Figure 8 ), and segment 11 has a middorsal fissure ( Figure 8F View Figure 8 ), which means that the segment is composed of two tergal and two sternal plates. To clarify these potential differences, the type material and supplementary material from the original description was reexamined, which revealed a similar morphology in these specimens. The description of C. flosculosa should therefore be emended regarding these details. The misinterpretations from the original description was due to the fact that most specimens were strongly contracted, and the anterior segment areas would most often be covered by the free flaps of the preceding segments. Long, papillary hairs emerging under the free flaps of segments 4 and 5 had been misinterpret as papillae from sensory spots, and the dorsal side of segment 11 had been completely covered in all specimens.
Notes on new observations: Cephalorhyncha flosculosa was described from the southwest coast of Turkey, near Bodrum and Fethiye ( Yıldız et al., 2016), thus finding the species in Antalya as well was no surprise. However , the species has so far been known from intertidal localities only, thus finding it subtidally at 2 to 3 m depth expands its habitat range slightly .
The confirmed absence of paradorsal sensory spots on segments 4 and 5 makes C. flosculosa even more similar with its close congener Cephalorhyncha liticola SØrensen, 2008. Still, the two species can be distinguished by the midventral flosculi, present in C. flosculosa only. This character can be difficult to observe though, and it requires SEM observations on a specimen without collapsed sternal plates. Thus, an easier way to distinguish the two species is by comparing sensory spot patterns on the posterior segments. The sensory spot distribution in the two species is basically identical on segments 1 to 8. Sensory spots on segment 9 differ considerably though, as C. liticola only has a pair of midlateral sensory spots on its tergal plate ( SØrensen, 2008), whereas C. flosculosa also has a pair of paradorsal and subdorsal sensory spots. The middorsal fissure of the tergal plate in C. flosculosa could potentially also be a difference from the condition in C. liticola . This species appears to have an undivided tergal plate on the terminal segment, but it would be preferable to have this confirmed from more specimens.
The middorsal division of the terminal segment is not uncommon among species of the smaller genera of Echinoderidae . About half of the species accommodated in Cephalorhyncha , Fissuroderes and Meristoderes has divided tergal plate on the terminal segment ( Neuhaus and Blasche, 2006, SØrensen et al., 2013).
| MD |
Museum Donaueschingen |
| ML |
Musee de Lectoure |
| PD |
Dutch Plant Protection Service, Culture Collection of Plant Pathogenic Bacteria |
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