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FIGURE 6 in Potential cryptic speciation in Mediterranean populations of Ophioderma (Echinodermata: Ophiuroidea)

Author: Stöhr Sabine
Boissin Emilie
Chenuil Anne
Publication venue
Publication date: 14/04/2009
Field of study

FIGURE 6. Brooding female of Ophioderma longicauda and SEM images of juveniles. Ventral disk aspect with juveniles visible in proximal bursal slits (A), close-up of juvenile escaping from bursal slit (B), SEM image of juvenile in bursal slit (C), dorsal aspect of juvenile (D), ventral aspect of juvenile (E), lateral arm of juvenile (F), ventral interradius of juvenile (G). AS, adoral shield; Asp, arm spine; ASS, adoral shield spine; LAP, lateral arm plate; TP, terminal plate. Arrows indicate juveniles in bursal slits. Scale bars (A, B), 1 mm, (C–G), 100 µm.Published as part of Stöhr, Sabine, Boissin, Emilie & Chenuil, Anne, 2009, Potential cryptic speciation in Mediterranean populations of Ophioderma (Echinodermata: Ophiuroidea), pp. 1-20 in Zootaxa 2071 (1) on page 13, DOI: 10.11646/zootaxa.2071.1.1, http://zenodo.org/record/532206

ZENODO

Fig. 11 in Resolving the Ophioderma longicauda (Echinodermata: Ophiuroidea) cryptic species complex: five sisters, three of them new

Author: Stöhr Sabine
Boissin Emilie
Chenuil Anne
Weber Alexandra Anh-Thu
Publication venue
Publication date: 31/12/2020
Field of study

Fig. 11. Ophioderma zibrowii sp. nov., holotype (SMNH-Type-9188), digital images. A. Dorsal aspect, note the naked radial shields. B. Ventral aspect. C. Ventral arm. D. Dorsal arm, note the entire plates. E. Jaw. F. Brooded juveniles in interradius (arrow). Abbreviations: DAP = dorsal arm plate; M = madreporite; OS = oral shield; RS = radial shield; VAP = ventral arm plate.Published as part of Stöhr, Sabine, Weber, Alexandra Anh-Thu, Boissin, Emilie & Chenuil, Anne, 2020, Resolving the Ophioderma longicauda (Echinodermata: Ophiuroidea) cryptic species complex: five sisters, three of them new, pp. 1-37 in European Journal of Taxonomy 600 on page 29, DOI: 10.5852/ejt.2020.600, http://zenodo.org/record/363777

Ophioderma zibrowii Stöhr & Weber & Boissin & Chenuil 2020, sp. nov.

Author: Stöhr Sabine
Boissin Emilie
Chenuil Anne
Weber Alexandra Anh-Thu
Publication venue
Publication date: 04/02/2020
Field of study

Ophioderma zibrowii sp. nov. urn:lsid:zoobank.org:act: 7FB245FD-C8DF-402A-A7B1-FA7D048AFB04 Figs 11–12; Table 1 Diagnosis Usually naked radial shields. Seven arm spines. Eight oral papillae. Colour pattern greenish brown to dark green variegated on dorsal and ventral disc, arms banded, with light and dark spots along distal dorsal plate edges, oral frame and ventral arms lighter. Largest known size 21 mm dd. Brooder. Etymology The species is named after Helmut Zibrowius for his important contributions in collecting material for this study. The existence of brooding Ophioderma in the Mediterranean Sea might still be unknown without his effort. Material examined Holotype MEDITERRANEAN SEA • &female; (brooding); southern Crete, Agios Pavlos; May 2012; A. Weber leg.; preserved in 95% ethanol; SMNH-Type-9188. Paratypes MEDITERRANEAN SEA • 1 &female; (brooding); same data as for holotype; SMNH-Type-9189 • 7 specimens; Greece, Symi Island, near Rhodes, Agios Georgios; 10 Aug. 2005; R. Graille leg.; preserved in 95% ethanol; SMNH-Type-9190 to 9196. Other material MEDITERRANEAN SEA • 18 specimens (mitochondrial COI lineage L3, nuclear cluster C5); Greece, northwestern Crete, Elounda, Plaka Beach; 2 Jul. 2008; Emilie Aegea leg.; preserved in 95% ethanol; SMNH-102712, 113690 to 13697, 11370 to 113704, 113709 to 113712 • 21 specimens (mitochondrial COI lineage L3, nuclear cluster C5); Greece, Rhodes, Kallithea Bay; 9 Sep. 2005; H. Zibrowius leg.; preserved in 95% ethanol; SMNH-99657, 113982, 113985, 113987 to 113990, 113992 to 114003, 114005, 114006 • 41 specimens (mitochondrial COI lineage L3, nuclear cluster C5); Greece, Crete; May 2012; A. Weber leg.; preserved in 95% ethanol; SMNH-147070 • 1 specimen (dd = 15.4 mm), dried dissociated ossicles and ossicles on two SEM stubs; same data as for preceding; SMNH-178455. Description Holotype (Fig. 11) Disc diameter 14.3 mm, one intact arm, all others removed for molecular analysis. Dorsal disc with dense cover of granules, radial shields naked, widely separated, visible part oval (Fig. 11A). Granules and scales crowd onto basal arms. Dorsal arm plates single on all joints, flat, overlapping, broadly fanshaped, twice as wide as long, with straight edges, wider distally than proximally (Fig. 1D). Up to seven conical, slightly pointed arm spines, about equal in length, half as long as arm joint, ventralmost spine thicker than others and blunt (Fig. 7C). Ventral disc covered by granules similar to dorsal disc. Adoral shields and oral plates covered by granules, oral shields naked (Fig. 11B). Seven to eight oral papillae, Lyman’s ossicle elongated, pointing into mouth slit, adoral shield spines two, block shaped, other papillae smaller, conical (Fig. 11E). Tooth papillae larger, conical, two in line with oral papillae. Oral shields triangular, twice as wide as long, straight distal edge, obtuse rounded proximal angle. Madreporite as wide as long. Adoral shield long, narrow, extending around the lateral edge of the oral shield, separating it from the arm. Adoral shields covered with granules, similar to disc granules. Proximal genital slits parallel to and as long as first and second joints. Distal genital slit parallel to and as long as fourth joint, at distance from disc edge. Bursae filled with brooded juveniles (Fig. 11F). Dorsal disc slightly variegated dark brown-green with grey, dorsal arms greyish green with brown bands, each light and dark band about three joints wide, a series of larger white and smaller black spots along the distal edge of each dorsal arm plate (Fig. 11A, D). Ventral disc as dark as dorsal, oral frame and ventral arms lighter grey-green (Fig. 11B). Arm spines grey-green with white tips, except ventralmost spine, which is white (Fig. 11 C–D). Oral papillae and tentacle scales white (Fig. 11C, E). Paratypes Disc diameter 9.7–13.5 mm.All have up to seven arm spines. Most paratypes have a green colour pattern similar to the holotype, one specimen is olive-brown. One paratype with granule-covered radial shields, all others naked. Oral papillae eight, in two specimens nine, but variable between jaws in an individual. Two specimens with two dorsal arm plates on 2–3 proximal joints on 1–3 arms. One specimen with 2–3 dorsal arm plates on proximal joints on three arms, on seven joints on one of those arms. One specimen has a parasitic snail (Ersilia Monterosato, 1872 sp.) on one arm. All paratypes lack part of an arm, which was used for molecular analysis. Non-paratypes (SMNH-147070) Disc diameter 8.4–20.5 mm. Specimens smaller than 10 mm dd had six arm spines, all others seven. Most specimens have a green colour pattern similar to the holotype, several were dark olive with numerous white granules scattered across the disc. Out of the 42 specimens, a single one had granule-covered radial shields, all others with naked radial shields. Most of the specimens above 10 mm dd had at least two proximal arm joints on at least one arm with two dorsal arm plates, up to seven joints and several arms with double plates in one animal. The plates were usually of equal size or there was a hairline crack along the midline of the plate. Rarely, a third dorsal arm plate was present on one or two joints. Oral papillae eight, rarely nine, but variable between jaws in an individual and not correlated to size. These specimens were used for thermotolerance and regeneration experiments. These specimens were kept in an aquarium for a year where experiments of thermotolerance and regeneration were conducted. Therefore, most arms show signs of regeneration. One specimen had bright white distal arms but no sign of healed breaks. Maximum size recorded for O. zibrowii sp. nov. was 21 mm dd (Weber et al. 2014). Skeletal elements (Fig. 12) Non-type specimen of 15.4 mm dd (SMNH-178455), completely dissociated. Radial shields elongated isosceles triangular, external surface with embossed oval of more finely meshed stereom in center of domed and thickened proximal half (only visible part in intact skeleton), row of eight pores curves around proximal dome (Fig. 12A, C). On inner side of radial shield, a large pore on distal half and a round patch with denser stereom, two low distal bulbs separated by a furrow (Fig. 12B). Dental plate consists of several pieces, sockets not penetrating the plate, bordered by low rim, tooth papillae sockets smaller, round, tooth sockets wide, oval (Fig. 12D). Adradial genital plate blade-like flat with bulbous distal end and large pore, distal pit with knob on one side, three ridges on other side (Fig. 12 E–F). Abradial genital plate much smaller and scale-like flat, distally wider than proximally (Fig. 12G). Oral plates longer than high, middle part markedly lower than ends, abradial muscle fossa rounded triangular, not reaching upper edge (Fig. 12H). On adradial oral plate proximoventral part four oral papilla sockets and pores, at proximoventral edge four granule sockets and pores (Fig. 12I). Vertebrae typically zygospondylus, with large dorsal and small ventral muscle flanges, no growth rings obvious (Fig. 12 J–K). Lateral arm plates compact, weakly curved around the arm, strongly convex distally, concave proximally, with ventral excavation for tube foot opening (Fig. 12 L–M). Two spurs at proximal external edge and counterparts on internal distal edge of lateral arm plates. Internal lateral arm plate with vertical row of three pores just below the plate centre, distal to curved vertical ridge, fourth pore in tentacle opening edge, small ventral knob, protruding beyond plate edge. Spine articulations inset in the distal plate edge with one thickened lobe, separating muscle and nerve opening. Remarks The species determination rests mainly on the genetic analyses. We chose the predominant genetic group (C5) to describe a new species, but due to its short reproduction period (May–June, Weber et al. 2014) most specimens of this cluster happen to have been collected outside the brooding time. Since brooding is one of the key characters of this species, we felt that the holotype should be a brooding female. It is not ideal that the chosen animal has only a single intact arm remaining, but in a pentaradially symmetric animal one arm is sufficient and representative of the others. Morphological differentiation from O. longicauda rests on the usually naked radial shields and the single, flat arm plates. Also, O. zibrowii sp. nov. usually lacks red pigments which are common in O. longicauda, whereas green pigments are common in O. zibrowii sp. nov. but absent in O. longicauda. In addition, O. zibrowii sp. nov. commonly has a series of white and black spots along the distal edge of the dorsal arm plates, which are shared with O. hybrida sp. nov. and O. guineense. The radial shields differ microscopically from those of O. longicauda in the clear demarcation of an embossed part with finer meshed stereom, representing the naked visible part of the radial shields in the intact animal. The major part of the radial shield is overlapped and covered by disc scales, obscuring its true shape. Possibly, the more elongated oral plates and higher lateral arm plates in O. zibrowii sp. nov. distinguish the species, but these small differences need to be studied with morphometric methods and larger samples. Brooding females have been collected from Cyprus and Lebanon, but they belong to another genetic cluster (C6). Morphologically they cannot be distinguished at this time and we consider them to be allopatric populations within the same species. They are excluded from the concept of the new species O. zibrowii sp. nov., as new evidence may in the future lead to them being recognized as a different species.Published as part of Stöhr, Sabine, Weber, Alexandra Anh-Thu, Boissin, Emilie & Chenuil, Anne, 2020, Resolving the Ophioderma longicauda (Echinodermata: Ophiuroidea) cryptic species complex: five sisters, three of them new, pp. 1-37 in European Journal of Taxonomy 600 on pages 28-32, DOI: 10.5852/ejt.2020.600, <a href="http://zenodo.org/record/3637773">http://zenodo.org/record/3637773</a&gt

ZENODO

Ophioderma africana Stöhr & Weber & Boissin & Chenuil 2020, sp. nov.

Author: Stöhr Sabine
Boissin Emilie
Chenuil Anne
Weber Alexandra Anh-Thu
Publication venue
Publication date: 04/02/2020
Field of study

Ophioderma africana sp. nov. urn:lsid:zoobank.org:act: 64021157-EA56-449B-9BCB-FD02F10CC67F Figs 7–8; Table 1 Diagnosis Mostly single dorsal arm plates, but several plates on some joints, eight arm spines, eight oral papillae. Colour dark brown dorsally, ventral disc as dark, ventral arms lighter brown, black and white spots along distal edge of dorsal arm plates. Maximum size under 19 mm dd (26 mm dd if non-type material is considered). Etymology The species is named for its area of collection, off (West) Africa. Material examined Holotype TROPICAL ATLANTIC OCEAN • Senegal, Dakar, Gorée Island, shipwreck Tacoma; depth 10 m; 28 Aug. 2007; H. Zibrowius leg.; scuba diving, hand collected; under stones; preserved in 95% ethanol; SMNH-Type-7484. Paratypes TROPICAL ATLANTIC OCEAN • 22 specimens (6 sampled for both COI and nuclear markers, mitochondrial COI lineage L 5, nuclear cluster C 2); same data as for holotype; SMNH-Type-7485 • 1 specimen, ossicles, 4 remaining arms, 2 SEM stubs with ossicles; same data as for holotype; dried; SMNH-Type-7486 • 11 specimens (including a separate vial with eggs that were spawned during collection); same data as for holotype; initially in formalin, then 80% ethanol; SMNH-Type-7487 • 4 specimens (2 used for both COI and nuclear markers, mitochondrial COI lineage L 5, nuclear cluster C 2); Senegal, Dakar, Cap Manuel; depth 7 m; 6 Sep. 2007; H. Zibrowius leg.; under stones; scuba diving, hand collected; preserved in 95% ethanol; SMNH-Type-7488 • 4 specimens (2 used for both COI and nuclear markers, mitochondrial COI lineage L 5, nuclear cluster C 2); Senegal, Madelene Islands; depth 10–12 m; 9 Sep. 2007; H. Zibrowius leg.; among piled up rocks; scuba diving, hand collecting; preserved in 95% ethanol; SMNH-Type-9184. Other material TROPICAL ATLANTIC OCEAN • 6 specimens (labelled as O. longicauda); Senegal, between Gorée and Tiaroye; depth 15–20 m; Feb.–Mar. 1952; Thorson leg.; preserved in ethanol; NHMD-225514 • 6 specimens (labelled as O. longicauda); Senegal, Dakar; Jan. 1928; Sudan exped.; H. Madsen leg.; dried; partial sample; NHMD-225517 • 10 specimens (labelled as O. longicauda); Dakar; 6 Jan. 1928; Sudan exped.; H. Madsen & O. Hagerup leg.; preserved in in ethanol; partial sample; NHMD-225523 • 1 specimen (labelled as O. longicauda); Senegal, Dakar, rocky coast; 3 Jan. 1928; H. Madsen leg.; preserved in ethanol; NHMD-225524. Description Holotype (Fig. 7) Disc diameter 18.7 mm, disc completely covered by small granules dorsally and ventrally (Fig. 7 A–C), including the radial shields (Fig. 7B). Disc scales with granules crowding onto arm base, covering first dorsal arm plate except for a mid-distal portion, second plate also covered by scales and granules laterally (Fig. 7 D–E). Dorsal arm plates flat, 2.5 times as wide as long, with straight distal edge, contiguous, mostly single, but joints with two plates common (often unequal in size) (Fig. 7 D–E). Eight arm spines, ventralmost one thicker and slightly longer than others (Fig. 7F). Ventral disc covered by granules similar to dorsal disc. Eight conical oral papillae, Lyman’s ossicle and adoral shield spines hardly distinguishable (Fig. 7G). Two larger tooth papillae at jaw tips in line with oral papillae, blocklike teeth. Oral shields rounded triangular, slightly wider than long, madreporite slightly wider than other oral shields and with central round depression. Adoral shield long, narrow, extending around the lateral edge of the oral shield, separating it from the arm. Adoral shields covered with granules, similar to disc in size. Proximal genital slits about one joint long, distal slits about three joints long (Fig. 7C). Ventral arm plates contiguous, as wide as long, with wide proximal angle, convex distal edge (Fig. 7F). Two oval scale-like tentacle scales, superimposed on the ventralmost spine. Disc dark brown dorsally, with some lighter brown patches. Dorsal arms dark brown, distally lighter and banded. Dorsal arm plates with small light brown and black dots along distal edge. Ventral disc as dark as dorsal, oral frame and ventral arms light orange brown (Fig. 7A, C). Paratypes Size range 12–18.4 mm dd. The specimens have dark brown to almost black dorsal discs (on some individuals with lighter patches), arms with dark and lighter bands. Ventral discs as dark as dorsal, oral frames and ventral arms lighter brown (Fig. 7H). Individuals with small light spots on the disc occur. Most specimens with black dots on the distal edge of the dorsal plates, but some without. Dorsal arm plates are mostly single, but most arms with several joints with two plates. Skeletal elements (Fig. 8) From specimen of 15.7 mm dd (SMNH-Type-7486) with mostly single dorsal arm plates but some small additional plates on few joints. Seven oral papillae, all similar except Lyman’s ossicle. Up to eight arm spines. Radial shields isosceles triangular with deeply concave abradial edge and abradial distal processes, distal center domed with small pores (the domed part is not covered by scales but with granules in the intact animal, all other areas are covered by scales) (Fig. 8A, C). Inner side of radial shield, on the distal articulation surfaces, two larger oval depressions and a smaller round one between these (Fig. 8B). Dental plate consists of several pieces with non-perforating sockets for 2–3 tooth papillae and single wide teeth, granule pores not obvious (Fig. 8D). Adradial genital plate blade-like flat with bulbous distal end and large pore, distal pit with knob on one side, two distal depressions on other side (Fig. 8 E–F). Abradial genital plate much smaller and scale-like flat, distally wider than proximally (Fig. 8G). Oral plates longer than high, middle part slightly lower than ends, adradially with four oral papilla pores on ventral edge of proximal part, small granule pores at ventral edge (Fig. 8I). Adradial distal muscle fossa wide ventrally, tapering dorsalwards, shorter than plate height, articulation area slightly higher than wide (Fig. 8H). Suture line diagonally across oral plate mid-line, separated easily during preparation on several jaws. Vertebrae typically zygospondylus, with large dorsal and small ventral muscle flanges, no growth rings obvious (Fig. 8 J–K). Lateral arm plates compact, weakly curved around the arm, strongly convex distally, concave proximally, with ventral excavation for tube foot opening (Fig. 8 L–M). Two spurs at proximal external edge and counterparts on internal distal edge of lateral arm plates. Internal lateral arm plate with vertical row of three pores just below the plate centre, fourth pore in tentacle opening edge, bent vertical proximal ridge and small ventral knob, protruding beyond plate edge. Spine articulations inset in the distal plate edge with one thickened lobe, separating muscle and nerve opening. Other specimens The specimens from NHMD possess mostly single dorsal arm plates, on few joints there are more than one and some specimens have on the most proximal joints a mosaic of slightly tumid plates. Some specimens have naked radial shields. They have 7–9 oral papillae, among which the adoral shield spine and Lyman’s ossicle are sometimes obvious, differing in shape from the other papillae. They are uniformly dark brown or variegated dark, on both dorsal and ventral sides. They range in size between 19 and 26 mm dd and are assigned to O. africana sp. nov. mostly by colour pattern and exclusion of O. longicauda from off West Africa. The specimen NHMD-225524, which measures only 5.7 mm dd, has a light brown dorsal pattern with faint spots, a cream white ventral surface, and single dorsal arm plates, similar to O. guineense and is reassigned to that species. Remarks Ophioderma africana sp. nov. shares the dark colour on both sides of the disc with O. longicauda, its spine numbers fall within the variability of both O. longicauda and O. guineense, it has as few oral papillae as O. longicauda (Table 1). These characters are however variable and small specimens may be difficult to identify. Nuclear and mitochondrial data were distinct from O. longicauda and all other clusters found (Weber et al. 2019), placing O. africana sp. nov. in cluster C2 and COI lineage L5. Some of the animals started spawning during collecting, which indicates that the species is a broadcast spawner, not a brooder.Published as part of Stöhr, Sabine, Weber, Alexandra Anh-Thu, Boissin, Emilie & Chenuil, Anne, 2020, Resolving the Ophioderma longicauda (Echinodermata: Ophiuroidea) cryptic species complex: five sisters, three of them new, pp. 1-37 in European Journal of Taxonomy 600 on pages 19-22, DOI: 10.5852/ejt.2020.600, <a href="http://zenodo.org/record/3637773">http://zenodo.org/record/3637773</a&gt

ZENODO

Ophioderma hybrida Stöhr & Weber & Boissin & Chenuil 2020, sp. nov.

Author: Stöhr Sabine
Boissin Emilie
Chenuil Anne
Weber Alexandra Anh-Thu
Publication venue
Publication date: 04/02/2020
Field of study

Ophioderma hybrida sp. nov. urn:lsid:zoobank.org:act: 72379251-8181-4B42-8CB6-881F0C144526 Figs 9–10; Tables 1–2 Diagnosis Species of Ophioderma with variable morphology. Dorsal arm plates single or as several pieces. Seven to 10 equal arm spines. Eight oral papillae. Colour pattern: disc dark brown or olive dorsally and ventrally, often with white spots. Dorsal arms dark brown with light brown or white and black spots, ventrally lighter brown. Maximum known size about 19 mm dd. Etymology This species has likely evolved by an ancient hybridization event between two species (O. longicauda and O. zibrowii sp. nov. or their respective ancestors), which the Latin word hybrida alludes to. It also refers to the mixed morphology of the species. Material examined Holotype MEDITERRANEAN SEA • Tunisia, Kelibia; 36°50′7.31″ N, 11°7′6.20″ E; depth 0.3–1.5 m; 3 Jul. 2013; Zined Marzouk & Alexandra Weber leg.; preserved in 95% ethanol; SMNH-Type-9185. Paratypes MEDITERRANEAN SEA • 11 specimens; same data as for holotype; SMNH-Type-9186 • 8 specimens; Tunisia, Monastir; 35°46′28.83″ N, 10°50′18.93″ E; depth 2–5 m; 25 Jun. 2013; A. Weber leg.; preserved in 95% ethanol; SMNH-Type-9187. Other material MEDITERRANEAN SEA • 3 specimens (with dorsal disc removed, but present); same data as for holotype; SMNH-178454 • 3 specimens; Tunisia, Tunis; 1849; Åberg leg.; SMNH-35614, 123374, 123375. Description Holotype (Fig. 9) Disc diameter 17.4 mm, two arms cut off near disc but present (Fig. 9 A–B). Radial shields covered by disc granules (Fig. 9A). Dorsal arm plates weakly tumid, as 1–3 pieces on about first 30 joints, when single twice as wide as long, distal edge straight or concave (Fig. 9 C–D). Ten arm spines, all about equal in length, ventralmost slightly wider. Ventral arm plates overlapping, squared, distal edge convex (Fig. 9E). Two oval scale-like tentacle scales, superimposed on the ventralmost spine. Ventral disc covered by granules similar to dorsal disc. Eight oral papillae, short, weakly pointed to round, Lyman’s ossicle large, pointing into mouth slit (Fig. 9F). Tooth papillae larger than oral papillae, teeth rounded block-shaped. Oral shield almost twice as wide as long, with wide proximal angle, distal edge slightly convex. Madreporite larger, almost as long as wide (Fig. 9B). Adoral shield long, narrow, extending around the lateral edge of the oral shield, separating it from the arm (Fig. 9F). Adoral shields covered with granules, similar to disc granules. Proximal genital slits angled from oral shield to second arm joint, distal genital slits at disc edge, two arm joints long. Disk dark brown dorsally with radiating lighter brown pattern and scattered white spots (Fig. 9A). Dorsal arms dark brown with light brown and dark spots along the distal plate edges and on some lateral edges (Fig. 9 C–D). Ventral disc and arms light greenish brown, oral shields darker (Fig. 9B). Variation The range of morphological variation is presented in Table 2 and on Fig. 10. The specimens vary in size from 9.8 to 18.7 mm disc diameter. Among the 23 examined specimens, the number of dorsal arm plate pieces varies considerably. Multiple plates or pieces have been found on the proximal arms, until about joint number 30, but not on all joints, and sometimes not on all arms (Fig. 10E). In most specimens, there are only two pieces, but in a few animals, multiple pieces were observed (Fig. 10E, H, N). Some specimens have only single dorsal arm plates (Fig. 10B, K). More pieces are present in the larger specimens but there appears to be only a weak size relation for this trait. Likewise, the number of arm spines and oral papillae is not related to disc diameter. All but two animals have granule covered radial shields. Colour variations are limited. All examined specimens have a dark brown or olive dorsal disc with varying white patterning (from spots to radiating lines) and a dark ventral disc, similar or lighter oral frame and ventral arms. The dorsal arms show alternating light and dark bands and a series of light and dark spots along the distal edge of the dorsal arm plates. Other specimens SMNH-35614 15.5 mm dd, SMNH-123374 16.3 mm dd, SMNH-123375 14.3 mm dd. Colour faded to light brown. Most of the granules rubbed off the discs, and status of the radial shields as naked/granule covered cannot be assessed, but they have an exposed area, devoid of scales. Eight oral papillae. Two to three dorsal arm plates on single joints (SMNH-123374), up to nine joints (SMNH-123375), up to 12 joints (SMNH-35614), variable between arms. Juveniles present in the bursae. Remarks The origin of this species through an ancient hybridization event between O. longicauda and O. zibrowii sp. nov. (or their ancestors) (Weber et al. 2019) is further supported by its high morphological variability. Multiple dorsal arm plates are typical of O. longicauda, and in some specimens of O. hybrida sp. nov. the most proximal joints bear several plates, forming a crowded mosaic pattern similar to O. longicauda. The usually granule covered radial shields are shared with all species except O. zibrowii sp. nov. (Table 1) and are probably evidence of O. longicauda (or its ancestor) being one of the ancestral species. The variation of arm spines and oral papillae overlap with both ancestral species and O. africana sp. nov., but O. guineense has a higher number of arm spines. Ophioderma hybrida sp. nov. shares the vivid colour pattern of the arms with O. zibrowii sp. nov. and O. guineense, whereas O. africana sp. nov. and O. longicauda are darker and the spots on the arms are less obvious in the former. So far, O. hybrida sp. nov. appears to be a smaller species with disc diameter under 20 mm, but more material is needed to confirm this. We believe that the reproductive mode of O. hybrida sp. nov. is brooding given that brooding individuals have been collected in Tunisia (Stöhr et al. 2009) and the ones examined in this study are morphologically more similar to O. hybrida sp. nov. than to O. zibrowii sp. nov., because they have more dorsal arm plates per joint. Yet, we cannot confirm it, as the brooding specimens from Tunisia were too old for genetic analyses (1849 and 1924; PCR amplification failed). In addition, all other O. hybrida sp. nov. specimens have been collected outside the reproductive season so examination of their gonads was inconclusive in determining their reproductive strategy.Published as part of Stöhr, Sabine, Weber, Alexandra Anh-Thu, Boissin, Emilie & Chenuil, Anne, 2020, Resolving the Ophioderma longicauda (Echinodermata: Ophiuroidea) cryptic species complex: five sisters, three of them new, pp. 1-37 in European Journal of Taxonomy 600 on pages 22-24, DOI: 10.5852/ejt.2020.600, <a href="http://zenodo.org/record/3637773">http://zenodo.org/record/3637773</a&gt

ZENODO

Ecological and genetic study of the cryptic species complex Ophioderma longicauda (Ophiuroidea : Echinodermata) : comparison between brooding and broadcasting lineages.

Author: Weber Alexandra
Publication venue
Publication date: 16/01/2015
Field of study

Ophioderma longicauda (Bruzelius, 1805) est un complexe d’espèces cryptiques incluant six lignées mitochondriales (L1-L6), dont certaines (L2-L3-L4) incubent leur descendance, alors que d'autres se reproduisent probablement via des larves lécithotrophes. Afin de définir les limites d’espèces dans le complexe O. longicauda, le statut reproductif des lignées L1 et L3 a été étudié. L’analyse morphologique et génétique a montré qu’il s’agissait d’espèces biologiques différentes, avec notamment différentes périodes de reproduction. De plus, l’analyse par DAPC de 31 marqueurs génétiques a montré que le complexe O. longicauda était constitué de six groupes génétiques distincts. Deuxièmement, l’influence des traits d’histoire de vie sur la connectivité et la diversité génétique a été étudiée. Pour ce faire, 10 marqueurs ont été séquencés pour six populations sympatriques des lignées L1 et L3 en Grèce. La structure génétique était très marquée pour l’espèce incubante L3, tandis que l’espèce dispersante L1 n’a pas montré de structure génétique à cette échelle. L’analyse de la diversité génétique pour ces 10 marqueurs a montré que celle des dispersantes était trois à quatre fois plus élevée que celle des incubantes. De plus, l’analyse de la diversité génétique dans les transcriptomes des L1 et L3 a montré qu’elle était 1.5 à 2 fois plus élevée chez les dispersantes que chez les incubantes. Finalement, deux canaux ioniques impliqués dans la mobilité des spermatozoïdes ont montré une évolution sous sélection positive. Ces résultats suggèrent que la compétition des spermatozoïdes pourrait être un mécanisme d’isolement pré-zygotique chez Ophioderma longicauda.Ophioderma longicauda (Bruzelius, 1805) is a cryptic species complex including six mitochondrial lineages (L1-L6), of which three (L2-L3-L4) brood their juveniles, whereas the other lineages most likely reproduce using lecithotrophic larvae. In order to define the species limits in the O. longicauda complex, the reproductive status of lineages L1 and L3 was studied. The morphological and genetic study showed that they were different biological species, with notably different reproductive periods. In addition, the analysis of 31 genetic markers using DAPC showed that the O. longicauda complex included six distinct genetic groups. Secondly, the influence of life-history traits on connectivity and genetic diversity was studied. To do so, 10 markers were sequenced for six sympatric populations of lineages L1 and L3 from Greece. The genetic structure was high for the brooding species, whereas the broadcasting species did not display any genetic structure at that scale. The analysis of genetic diversity for these 10 markers showed that diversity was three to four times higher in broadcasters than in brooders. In addition, the analysis of genetic diversity in the L1 and L3 transcriptomes showed that diversity was 1.5 to 2 times higher in broadcasters than in brooders. Finally, two ion channels involved in sperm motility showed an evolution under positive selection. These results suggest that sperm competition might be a mechanism of pre-zygotic isolation in Ophioderma longicauda

Theses.fr

A study of coralligenous habitats biodiversity and of the influence of environmental factors using genetic tools : from engineer species populations to communities

Author: De Jode Aurélien
Publication venue
Publication date: 30/11/2018
Field of study

La biodiversité englobe toute la diversité des éléments du vivant des molécules à la biosphère et différents niveaux de biodiversité peuvent être distingués. Les habitats coralligènes sont des constructions biogènes calcaires emblématiques de la mer Méditerranée principalement construits par des espèces d’algues rouges calcaires puis consolidés par les squelettes calcaires de différents invertébrés marins. La structure tridimensionnelle formée abrite de nombreuses espèces, faisant des habitats coralligènes un point chaud de biodiversité en mer Méditerranée. L’étude de la diversité génétique chez une algue rouge calcaire ingénieure a révélé la présence d’espèces cryptiques dont l’abondance relative varie en fonction de la localité et de la profondeur. Cette approche a aussi montré que la diversité génétique chez l’espèce cryptique la plus abondante est principalement structurée par des processus neutres de dérive et de migration eux-mêmes influencés par la courantologie. L’étude de la diversité en espèces des communautés, réalisée par une approche de métabarcoding, a révélé une forte diversité au sein des habitats coralligènes ainsi qu’une forte influence des variables environnementales sur la composition des communautés d’espèces. La comparaison des deux niveaux de diversité révèle que la diversité génétique et la diversité spécifique sont positivement corrélées pour la composante alpha et non corrélées pour la composante beta .Cette thèse contribue à améliorer nos connaissances de la biodiversité et du fonctionnement écologique des habitats coralligènes et a aussi permis le développement des certaines méthodes potentiellement applicable au monitoring de ces habitatsBiodiversity encompasses the diversities of all the living elements from the molecules to the biosphere and several levels of biodiversity can be distinguished. Coralligenous habitats are emblematic calcareous biogenic constructions of the Mediterranean Sea mainly built by calcareous red algae and consolidated by calcareous skeletons built by several mine invertebrates. The complex three-dimensional structure shelters for a huge variety of species, and coralligenous habitats are considered to be one of the biodiversity hotspot of the Mediterranean Sea. The study of the genetic diversity of a engineering calcareous red algae, by capture sequencing, revealed that this nominal species is actually composed of eight cryptic species which relative abundances vary among localities and depth. This approach also showed that genetic diversity in the most abundant cryptic species, is shaped by neutral processes of drift and migration strongly influenced by oceanic currents in Marseilles area. The species diversity in communities was studied using a metabarcoding approach. It revealed the high diversity found in these habitats and the important effect of environmental variables on the species communities composition. The comparison between both level of diversities established that that genetic diversity and species diversity are positively correlated for the alpha component of diversity and uncorrelated for the beta component.These work contribute to improve our knowledge of the biodiversity and ecological functioning of these habitats. Some of the methods developments and tuning implemented during this study could be used in monitoring applications of these habitat

Theses.fr

Ophioderma Muller & Troschel 1840

Author: Stöhr Sabine
Boissin Emilie
Chenuil Anne
Weber Alexandra Anh-Thu
Publication venue
Publication date: 04/02/2020
Field of study

Genus Ophioderma Müller & Troschel, 1840 Type species Ophioderma longicauda (Bruzelius, 1805). Type locality Mediterranean Sea. Diagnosis Disc with dense granule cover dorsally and ventrally, including jaws; oral shields (and in some species adoral shields) naked. Arm spines numerous, up to half arm joint length. Multiple dorsal arm plates present in several species. Two short genital slits to each bursa. Single rows of numerous oral papillae. Lyman’s ossicle present. Oral plate ridge spines present. Dental plate in several pieces, with nonperforating sockets of two types, round and small for tooth papillae, wide slit-like for teeth. Dissociated radial shield triangular, with distal abradial process, large internal pore and several smaller external pores. Lateral arm plates with two short spurs on the outer proximal edge and corresponding spurs on the inner distal edge. Adradial genital plate elongated, curved, proximal end with depression and round knob. Abradial genital plate flat, trapezoidal, about half as long as adradial plate. Remarks Multiple dorsal arm plates are known from several species of Ophioderma and previous authors have assumed that they developed by division or fragmentation (Ziesenhenne 1955; Hendler et al. 1995). Hendler (2018) questioned this assumption because the morphogenesis of these plates is not yet known and recommended microstructural analysis of the stereom. Although this question lies outside the scope of this study, we have made some observations that may help to understand the process. In young specimens of all studied species, all joints are covered by a single wide dorsal arm plate. In larger specimens, additional plates appear on the proximal (= oldest) joints and they align as if they were a single plate. Thin hair-like cracks were observed on some joints in smaller specimens with otherwise entire plates. The number of plates increases on the basal joints and distalwards with growth. There does not seem to be a pre-determined division plane and the split can occur along the mid-longitudinal of the first-formed plate or offset to left or right, seemingly at random. The separate plates appear to continue to grow, obtaining various shapes, and all their edges become rounded. When the number of plates increases, a mosaic pattern appears where plates are no longer aligned across the arm, and it may be difficult to decide to which arm joint a particular plate belongs. Fragmentation seems a plausible explanation for the formation of multiple plates that replace the first plate. The additional plates that are not in line with the original plate may form either independently or from additional divisions. Ziesenhenne (1955) suggested that broken arm plates may be the result of mechanical injury from falling stones, and this may be an alternative explanation for the existence of multiple arm plates or there may be two mechanisms at work. Possibly, only multiple plates on proximal arm joints should be considered as species-specific characters, whereas the occurrence of a few cracked plates further out on the arms is more likely the result of injury. Due to these open questions, we have refrained from using the terms fragmentation or division when describing the multiple dorsal arm plates. With regard to dental plates, Hendler (2018) found that fragmentation occurs in one species of Ophioderma, and it is likely that this applies to the whole genus.Published as part of Stöhr, Sabine, Weber, Alexandra Anh-Thu, Boissin, Emilie & Chenuil, Anne, 2020, Resolving the Ophioderma longicauda (Echinodermata: Ophiuroidea) cryptic species complex: five sisters, three of them new, pp. 1-37 in European Journal of Taxonomy 600 on pages 6-8, DOI: 10.5852/ejt.2020.600, http://zenodo.org/record/363777

ZENODO

Influence of multi-scale connectivity via larval dispersal on population structure and patterns of biodiversity in the Mediterraean sea

Author: Legrand Térence
Publication venue
Publication date: 21/03/2022
Field of study

Dans l’océan, de nombreuses espèces sédentaires dispersent durant leurs premiers stades de vie en relâchant dans la colonne d’eau des cohortes de propagules (œufs, larves, fruits, etc.) qui sont ensuite transportées par les courants marins. La connectivité, processus qui caractérise de tels échanges d’individus et de gènes dans l’espace, est cruciale dans la dynamique démographique et la diversité génétique des populations marines. En combinant des simulations de transport de propagules par les courants marins avec des données biologiques et génétiques observées en mer Méditerranée pour près de 50 espèces différentes, cette thèse a permis de caractériser les patrons spatiaux de connectivité démographique et de définir la connectivité génétique à partir d’événement successifs de dispersion. On a pour la première fois estimé la probabilité pour deux populations de partager des ancêtres communs, ce qui s’avère être le meilleur modèle pour prédire le flux de gènes. Ces travaux proposent de nouvelles avancées méthodologiques favorisant la compréhension de la connectivité multi-échelle qui est essentielle à une bonne gestion et sauvegarde des écosystèmes.In the marine realm, many coastal species disperse thanks to ocean currents during their early life stages by drifting propagules (eggs, larvae, fruits, etc.). Such exchanges of individuals or genes induce connectivity, which influences fundamental processes like population dynamics and genetic diversity. In this thesis, we combine Lagrangian modelling of transport processes with biological as well as genetic data observed in the Mediterranean Sea for almost 50 phylogenetically divergent species, to characterise spatial patterns of demographic connectivity and model genetic connectivity arising from consecutive dispersal events. We assess, for the first time, genetic cohesiveness among populations that share a common ancestor and show that it outperforms all previous approaches of gene flow predictions. Our work offers great promises to better understand and evaluate connectivity through passive dispersal, an essential pre-requisite for appropriate management and conservation of marine ecosystems and biodiversity

Theses.fr

Towards a spatialized approach to marine spatial planning : case study for sessile invertebrate populations in the Gulf of Lion

Author: Blouet Sylvain
Publication venue
Publication date: 06/07/2023
Field of study

La planification spatiale marine est un enjeu d’avenir pour la conservation des ressources marines, mais notre compréhension de l’agencement spatial des zones de conservation et des zones d'aménagement pour favoriser la persistance des populations n’est pas si claire. L’étude des échelles spatiales structurant la distribution des espèces et des processus influençant la dynamique et la persistance des populations marines est donc essentielle pour une approche spatialisée de l'organisation des espaces marins. Ce travail de thèse s’est donc organisé autour de deux objectifs : (i) appréhender les échelles locales et régionales structurant la distribution spatiale des invertébrés sessiles dans les habitats naturels et artificiels (partie 2 et partie 3) et (ii) évaluer comment l’intégration de la connectivité fonctionnelle associée à la dispersion larvaire dans un réseau hybride d’habitats naturels et d’habitats artificiels influencent les schémas prospectifs spatialisés d'extension de la conservation dans le golfe du Lion. Les approches choisies combinent des outils de modélisation et des inventaires à haute résolution d'invertébrés sessiles communs sur les habitats naturels et sur les récifs artificiels. La partie 2 examine la distribution spatiale régionale de 5 espèces de gorgones en utilisant un modèle de niche écologique, à partir de prédicteurs hydrologiques et géomorphologiques (courants de fond, température de surface, turbidité, profondeur, pente, rugosité, orientation des parois). La structuration spatiale de 4 des 5 espèces de gorgones peut s’expliquer par ces facteurs. Dans la partie 3, les effets de facteurs locaux (forme, profondeur et durée d'immersion) et régionaux (zone géographique) ont été évalués en examinant les assemblages de cinq espèces aux traits d'histoire de vie contrastés. Le positionnement géographique a été prévalent sur les facteurs locaux dans la colonisation des RA. L'approche multi spécifique réalisée dans les parties 2 et 3 a montré d’importances différentes du rôle de la dispersion et des facteurs abiotiques sur la structuration spatiale (locale et régionale) des espèces. Dans la partie 4, un schéma prospectif d'extension de la conservation a été simulé pour évaluer l'intégration de la connectivité fonctionnelle au sein du réseau de substrats rocheux naturels et avec l’ajout du réseau des récifs artificiels. Le réseau d'aires marines protégées est fortement modifié quand la connectivité fonctionnelle au sein de l’habitat naturel rocheux fragmenté est prise en compte. Le réseau des récifs artificiels, ajoutant des points relais dans le réseau des habitats naturels, modifie le schéma prospectif. Ces résultats soulignent l’importance d’intégrer la connectivité fonctionnelle dans la planification spatiale marine et le potentiel impact de l’installation ou du démantèlement de récifs artificiels.Marine spatial planning is a future issue for the conservation of marine resources, but our understanding of the spatial arrangement of conservation zones and management zones to promote the persistence of populations is not so clear. The study of spatial scales structuring the distribution of species and processes influencing the dynamics and persistence of marine populations is therefore essential for a spatialized approach to the organization of marine spaces. This thesis work is therefore organized around two objectives: (i) to understand the local and regional scales structuring the spatial distribution of sessile invertebrates in natural and artificial habitats (part 2 and part 3) and (ii) to evaluate how the he integration of functional connectivity associated with larval dispersal in a hybrid network of natural habitats and artificial habitats influences the spatialized prospective schemes of conservation extension in the Gulf of Lion. The chosen approaches combine modelling tools and high-resolution inventories of common sessile invertebrates on natural habitats and on artificial reefs. Part 2 examines the regional spatial distribution of 5 gorgonian species using an ecological niche model, based on hydrological and geomorphological predictors (bottom currents, surface temperature, turbidity, depth, slope, roughness, wall orientation). The spatial structuring of 4 of the 5 species of gorgonians can be explained by these factors. In part 3, the effects of local (shape, depth and duration of immersion) and regional (geographical area) factors were evaluated by examining the assemblages of five species with contrasting life history traits. Geographical positioning prevailed over local factors in AR colonization. The multi-specific approach carried out in parts 2 and 3 showed different importance of the role of dispersal and abiotic factors on the spatial structuring (local and regional) of species. In Part 4, a prospective conservation extension design was simulated to assess the integration of functional connectivity within the natural hard bottom and with the addition of the artificial reef network. The network of marine protected areas is strongly modified when the functional connectivity within the fragmented rocky natural habitat is taken into account. The network of artificial reefs, adding stepping stone in the network of natural habitats, modifies the prospective design. These results highlight the importance of integrating functional connectivity into marine spatial planning and the potential impact of installing or dismantling artificial reefs

Theses.fr