A new genus and a new species of dendrochirotid, Thandarum hernandezi gen. et sp. nov., is described from Buenos Aires coast in the Southwestern Atlantic. For this species is quite significant the body U shape, up to 14.08 mm (along the trivium), with double row of podia restricted to the ambulacra. Other features are ossicles from body wall with buttons and 4 pillar tables, tube feet with rods and end plate star-shaped; the introvert with rosettes and tentacles with rods. These characteristics require the recognition of a new genus, and the new species and represents the first sclerodactylid reported in Argentinean waters.Fil: Martinez, Mariano Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Brogger, Martin Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentin

Brogger, Martin Ignacio

Martinez, Mariano Ignacio

Zootaxa

English

Martinez, Mariano I., Brogger, Martín I. (2012): Thandarum hernandezi, a new genus and new species of sea cucumber family Sclerodactylidae (Echinodermata: Holothuroidea: Dendrochirotida) from the Southwestern Atlantic Ocean. Zootaxa 3304: 63-68, DOI: 10.5281/zenodo.28095

Martinez, Mariano I.

Brogger, Martín I.

ZENODO

Thandarum hernandezi, a new genus and new species of sea cucumber family Sclerodactylidae (Echinodermata: Holothuroidea: Dendrochirotida) from the Southwestern Atlantic Ocean

CONICET Digital

Accepted by M. Eleaume: 26 Mar. 2012; published: 8 May 2012ZOOTAXAISSN 1175-5326  (print edition)ISSN 1175-5334 (online edition)Copyright © 2012  ·  Magnolia PressZootaxa 3304: 63–68    (2012) www.mapress.com/zootaxa/ Article 63Thandarum hernandezi, a new genus and new species of sea cucumber family Sclerodactylidae (Echinodermata: Holothuroidea: Dendrochirotida) from the Southwestern Atlantic OceanMARIANO I. MARTINEZ1,2 & MARTÍN I. BROGGER11Laboratorio de Ecosistemas Costeros, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia” (CONICET), Av. Ángel Gal-lardo 470 (C1405DJR), Buenos Aires, Argentina. E-mail: mmartinez@macn.gov.ar; mbrogger@bg.fcen.uba.ar2Corresponding authorAbstractA new genus and a new species of dendrochirotid, Thandarum hernandezi gen. et sp. nov., is described from Buenos Airescoast in the Southwestern Atlantic. For this species is quite significant the body U shape, up to 14.08 mm (along thetrivium), with double row of podia restricted to the ambulacra. Other features are ossicles from body wall with buttonsand 4 pillar tables, tube feet with rods and end plate star-shaped; the introvert with rosettes and tentacles with rods. Thesecharacteristics require the recognition of a new genus, and the new species and represents the first sclerodactylid reportedin Argentinean waters.Key words: Sclerothyoninae, Thandarum hernandezi gen. et sp. nov., holothurian, Argentine SeaIntroductionOn the basis of the holothurians of South Africa, Thandar (1989) revised and modified the family Sclerodactylidae.He recognised the subfamily Cladolabinae for forms with 15–20 tentacles and he divided the included 10-tentacledtaxa, based on the form of the calcareous ring, into two subfamilies; Sclerodactylinae and Sclerothyoninae. Thesubfamily Sclerothyoninae described by Thandar (1989) has 10 tentacles with a not tubular calcareous ring. Forthis subfamily are Sclerothyone with table ossicles from body wall with or without a handle on one side and usuallyan arched spire with or without teeth and Temparena with table ossicles from body wall without handles. This twogenus are from South Africa and erected by Thandar (1989).For Southwestern Atlantic Ocean, Ludwig (1887) and Cherbonnier (1961) described two sclerodactylids,Pseudothyone belli (Ludwig) with 10 tentacles and Euthyonidiella dentata Cherbonnier with 20, both with distribu-tion in Brazil.For the Argentine Sea waters, Tommasi (1974) and Tommasi et al. (1988) studied the holothurians near Rio dela Plata and Mar del Plata, and Hernández (1981) studied specimens from Puerto Deseado (47º45’S; 65º55’W), butnone of these works reported species of the family Sclerodactylidae in the area. In the present article we describe a new genus and a new species of Sclerodactylidae from the Argentiniancoast, which represents the first report for this family in Argentinean waters.Material and methodsSamples were collected onboard B/O “Puerto Deseado” using an Agassiz trawl. Some samples were preserved inethanol 96% and others in formalin and then conserved in ethanol 70%. Holotype and paratypes are deposited inthe Invertebrate Collection of the Museo Argentino de Ciencias Naturales “Bernardino Rivadavia” (MACN-In),Buenos Aires, Argentina. Permanent slides of ossicles of the holotype are lodged in MACN-In. Digital photos of MARTINEZ & BROGGER64  ·  Zootaxa 3304  © 2012 Magnolia Pressspecimens were taken in the laboratory using a Nikon digital camera D100. Digital images of ossicles were takenusing Zeiss Axio Imager Z1 microscope with Axiocam HRc digital camera and Axiovision software.For scanning electron microscope (SEM) examinations of calcareous ring and ossicles, small pieces of thebody wall were macerated in sodium hypochlorite solution and then rinsed several times in distilled water, ethanol96% and air dried. Finally, the ossicles were transferred to aluminum stubs and observed under SEM.ResultsSystematicsOrder Dendrochirotida Grube 1840Family Sclerodactylidae Panning 1949Subfamily Sclerothyoninae Thandar 1989Diagnosis (Thandar 1989): Tentacles 10, ventral-most two much reduced. Calcareous ring not tubular, radial andinterradial plates united at base only; posterior paired processes of radial plates, long, 3–8 times the height of ring,either entire of broken into several pieces.Type genus: Sclerothyone Thandar 1989Key for genera of the subfamily Sclerothyoninae (modified from Thandar 1989)1 Table ossicles from body wall with two pillars  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2- Table ossicles from body wall with four pillars and buttons  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thandarum gen. nov.2 Table ossicles from body wall with or without a handle on one side and usually an arched spire with or without teeth  . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  Sclerothyone Thandar 1989- Table ossicles from body wall without handles, and smooth multilocular plates  . . . . . . . . . . . . . . . . Temparena Thandar 1989Thandarum gen. nov.Diagnosis. Small to medium-sized forms, up to 14.08 mm length. Tentacles 10, with two ventral tentacles smallerthan others. Non-retractile podia in five series, restricted to the ambulacra. Radials of the calcareous ring with longforked tails. Body wall with 4-pillared tables and buttons. Tube feet with rods and star-shaped endplates. Tentacleswith rods, and rosettes in the introvert.Type species. Thandarum hernandezi sp. nov.Etymology. This genus is named after Dr. Ahmed S. Thandar from the University of KwaZulu-Natal, Durban,Republic of South Africa, in recognition for his contributions to the taxonomy of holothurians and, particularly, ofthe family Sclerodactylidae. The gender is neuter.Remarks. In comparison with Sclerothyone and Temparena species, Thandarum gen. nov. presents 4 pillartables and buttons on the body wall.Thandarum hernandezi sp. nov.(Figures 1, 2)Type material. Holotype: 11.50 mm length, one individual and 4 slides with ossicles. Argentine Sea, “Mejillón II”Expedition (15 Sep. 2009), St. nº 24 (36°09,567’S; 55°53,649’W), 15 m. MACN-In nº 39256. Paratypes: Six indi-viduals, 14.58 mm; 14.08 mm; 13.96 mm; 13.86 mm; 13.03 mm; and 10.40 mm. Same locality and date. MACN-Innº 39257/1-6.Diagnosis. Body U shaped, up to 14.08 mm with double row of podia restricted to the ambulacra. Ossicles Zootaxa 3304  © 2012 Magnolia Press  ·  65NEW GENUS AND SPECIES OF SCLERODACTYLIDAEfrom body wall with buttons and 4 pillar tables. Tube feet with rods, end plate star-shaped. Introvert with rosettesand tentacles with rods.Etymology. This species is dedicated to Dr. Domingo Andrés Hernández, for his contributions to the taxon-omy of the Argentine Sea holothurians, and for being the starter of holothurians studies in Argentina. This epithet isuse as a noun in apposition.FIGURE 1. Holotype of Thandarum hernandezi gen. et sp. nov. A. Dorsal view; B. Ventral view; C. Calcareous ring shape.Scale bars: A and B = 1 mm. MARTINEZ & BROGGER66  ·  Zootaxa 3304  © 2012 Magnolia PressFIGURE 2. Ossicles of Thandarum hernandezi gen. et sp. nov. A. Body wall buttons; B. Tables with four pillars from bodywall; C. Rods from podia and star-shaped end plate; D. Rods from tentacles and rosettes from introvert. Scale bars: A, C and D= 50 μm, B = 100 μm.Description. (Based on the holotype) Body curved, skin usually soft; live color orange-pink, and white in pre-served state; anus and tentacles up turned; 10 dendritic tentacles, 2 ventral smaller; body wall thin with double rowof podia restricted to the radii; trivium and bivium complete with well developed podia (Fig. 1 A–B); calcareousring not tubular, radial and interradial plates joined only at the base, radials with posterior prolongations made up ofa mosaic of 3–4 pieces; ratio of radial/interradial length approximately 1:3 (Fig. 1 C). A single polian vesicle. Stonecanal bifurcated; one madreporite with two kidneys shaped. Respiratory trees with multiple branches extending tothe half part of the body. Gonads attached to the gonoduct at the middle part of the body, with multiple branchesextended all over the coelom cavity. Ossicles in body wall of two types. Buttons typically 50–80 µm long with only4 to multiple perforations (Fig. 2 A) and 4 pillar tables, typically of 130 µm long and 260 µm across (Fig. 2 B). Zootaxa 3304  © 2012 Magnolia Press  ·  67NEW GENUS AND SPECIES OF SCLERODACTYLIDAETube feet with rods with 2 middle and 2 terminal holes; end plate star-shaped with multiple perforations typically80–120 µm across (Fig. 2 C). Introvert with rosettes 40-55 µm long and tentacles with rods typically 80–100 µmlong with only 1 to multiple terminal perforations (Fig. 2 D). No differences are observed between the holotype andparatypes.Type locality. Off Buenos Aires (36°09.567’S, 55°53.649’W), Argentina.Habitat. Sand.Remarks. All the specimens collected are distinctive and have genus type characteristics. In comparison withSclerothyone and Temparena species, Thandarum hernandezi gen. et sp. nov. presents 4 pillar tables. For South-western Atlantic waters, Pseudothyone belli has knobbed buttons with handle (Ludwig 1887) not observed on T.hernandezi. Also from Brazil Cucumaria manoelina Tommasi 1971 has 4 pillar tables but no material was found ofC. manoelina, the type is lost, for this reason comparisons were made with the original description from Tommasi(1971). The differences between the two species are in the number of rows of podia and the shape of the ossicles. InC. manoelina 5 lines of podia were described, while in Thandarum hernandezi gen. et sp. nov. a double row ofpodia were observed. The tegument buttons have some differences in the number of holes, more in C. manoelinathan T. hernandezi. For the podia introvert and tentacles the rosettes and rods have differences in shape, the rosettesin C. manoelina are circular and oblong in T. hernandezi. The rods on T. hernandezi has more holes than in C.manoelina, also the holes in T. hernandezi are restricted to the ends. Also, C. manoelina has tables with more holesand a reduced diameter than the observed for Thandarum hernandezi gen. et sp. nov.DiscussionThandar (1989) discussed the calcareous rings forms of the family Sclerodactylidae, Phyllophoridae andCucumariidae, and resumed the history of the family Sclerodactylidae. Comparing the shape of the different calcar-eous rings forms, Thandarum hernandezi gen. et sp. nov. conform within the Sclerothyoninae. In comparison withSclerothyone and Temparena, Thandarum gen. nov. has 4 pillar tables, and also there are no plates in the introvertneither in the tentacles, the latter characteristics are observed in both members of Sclerothyoninae. Holothurian fauna from southern Argentine Sea waters is closely related to that of southern Chile (Pawson1969), including the absence of reports on Sclerodactylidae. There are also species like Cladodactyla crocea (Les-son), Pseudocnus dubiosus leoninus (Semper) and Pseudocnus perrieri (Ekman) that do not span north into Uru-guayan neither Brazilian waters (Tommasi 1971, 1974; Hernández 1981; Tommasi et al. 1988; Tiago & Ditadi2001). The reason of this pattern of distribution could be the effect of low salinity of the Rio de la Plata, that acts asa biogeographical barrier for some echinoderms (Tommasi et al. 1988), like Pseudothyone belli and Euthyonidielladentata, both sclerodactylids from north side of the Rio de la Plata, and also for Thandarum hernandezi gen. et sp.nov., restricted to south side of the Rio de la Plata. Although it is important to mention that at some deep this effectcould probably allow some exchange of fauna from one side to the other of the Río de la Plata, and this couldexplain the registry on C. manoelina that appear to be closely related with T. hernandezi.The present represents the first report on the family Sclerodactylidae from Argentina and also the first reporton the subfamily Sclerothyoninae, which was only known for South Africa (Thandar 1989). This distribution of thesubfamily Sclerothyoninae occurs also with the subfamily Cucumariinae Panning, genus Cladodactyla Brandt, forwhich Cladodactyla crocea has a South Western Atlantic distribution and Cladodactyla brunspicula Thandar 2008for South Africa.AcknowledgmentsWe are grateful for the assistance with the photographs and taxonomic aspects to Guido Pastorino and to Pablo E.Penchaszadeh, whom also, with Julio A. Arriaga Ochoa, made helpful observations to the manuscript. We thankAlejandro Tablado, curator of the Invertebrate Collection of the MACN. This work has been partially funded bygrants BID PICTR 1869 from the Agencia Nacional de Promoción Científica y Tecnológica (Argentina) and PIP2788 from CONICET (Argentina). We also want to specially thank to CONICET and the crew of the B/O “PuertoDeseado” for assistance during the 2009 expedition. Finally we are particularly grateful to Dr. Marc Eléaume andtwo anonymous reviewers for corrections and suggestions. MARTINEZ & BROGGER68  ·  Zootaxa 3304  © 2012 Magnolia PressReferencesCherbonnier, G. (1961) Deux nouvelles espèces d´holothuries dendrochirotes des côtes Brésiliennes. Bulletin du MuséumNational d´Histoire Naturelle 2º série, 33, 611–615.Grube, A.E. (1840) Actinien, Echinodermen und Würmer des Adriatischen- und Mittelmeers. J.H. Bon, Königsberg, 1–92.Hernández, D.A. (1981) Holothuroidea de Puerto Deseado (Santa Cruz, Argentina). Revista del Museo Argentino de CienciasNaturales "Bernardino Rivadavia", 4, 151–168.Ludwig, H. (1887) Die von G. Chierchia auf der Fahrt der Kgl. Ital. Corvette "Vettor Pisani" gesammelten Holothurien. Zoolo-gische Jahrbücher, 2, 1–36.Panning, A. (1949) Versuch einer Neuordnung der Familie Cucumariidae (Holothurioidea, Dendrochirota). ZoologischeJahrbücher Abteilung für Systematik, Ökologie Geographie Tiere, 78, 404–470.Pawson, D.L. (1969) Holothuroidea from Chile report no. 46 of the Lund University Chile expedition 1948-1949. Sarsia, 38,121–146.Thandar, A.S. (1989) The sclerodactylid holothurians of southern Africa, with the erection of one new subfamily and two newgenera (Echinodermata: Holothuroidea). South African Journal of Zoology, 24(4), 290–304.Thandar, A.S. (2008) Additions to the holothuroid fauna of the southern African temperate faunistic provinces, with descrip-tions of new species. Zootaxa, 1697, 1–57.Tiago, C.G. & Ditadi, A.S.F. (2001) Holothurians from the Brazilian coast: A historical survey. In: Barker, M. (Ed.), Echino-derms 2000: Proceedings of the 10th International Echinoderm Conference. Balkema, Lisse, The Netherlands, pp. 379–384.Tommasi, L.R. (1971) Equinodermes do Brasil. I. Sobre algumas especies novas e outras pouco conhecidas, para o brasil.Boletim do Instituto Oceanográfico, 20, 1–22.Tommasi, L.R. (1974) Equinodermes do Brasil. III. Observacoes sobre algumas espécies coletadas durante as viagens do N/Oc."Almirante Saldanha". Boletim do Instituto Oceanográfico, 23, 1–15.Tommasi, L.R., Cernea, M.C.W. & Condeixa, M.C.G. (1988) Equinodermes coletados pelo N/Oc. "Almirante Saldanha", entre26°59´S e 38°39´S. Relatório interno do Instituto Oceanográfico, 22, 1–11.

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Thandarum hernandezi, a new genus and new species of sea cucumber family Sclerodactylidae (Echinodermata: Holothuroidea: Dendrochirotida) from the Southwestern Atlantic Ocean

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