Ontogenetic variation of the ossicles inPseudothyone belli(Ludwig, 1887) with a description of a new Sclerodactylidae (Echinodermata: Holothuroidea: Dendrochirotida) from Southwestern Atlantic

Additions to the Morphology of the Cucumariidae. I. Intraspecific Variation of the Retractor Muscle in Parathyone braziliensis (Verrill, 1868) and Thyonidium seguroensis (Deichmann, 1930) (Holothuroidea: Dendrochirotida)

“…Thandar (1998;2001), for instance, reported that the point of origin of the retractor muscle at the longitutinal muscle is anterior to the midpoint of the body length in Psolidothuria octodactyla Thandar, 1998 (Vaneyellidae) and Rhopalodinaria minuta Cherbonnier, 1970 (Rhopalodinidae), respectively. Such is also the case in Paulayellus gustavi Martins and Tavares, 2018a, Sclerothyone oloughlini Martins and Tavares, 2019, S. reichi Martins and Tavares, 2019, Thorsonia hedingi Martins and Tavares, 2022, Selenkiella siamense Heding and Panning, 1954, Phyllophorella robusta Heding and Panning, 1954 and Thyone florianoi Martins and Tavares, 2018b (Phyllophoridae) (Martins and Tavares 2018a, b;2019;2022;Martins and Souto 2019).…”

“…Contrary, the retractor muscle departs from the longitudinal muscle posteriorly to the midpoint of the body length in Oloughlinia discovery (Heding, in Heding and Panning, 1954) (Sclerodactylidae) (Martins and Tavares 2022;Kroh et al 2022) and about at the midpoint of the body length in Havelockia smirnovi Martins, 2019 (Sclerodactylidae) and Thyone waltinhoi Martins and Souto, 2019 (Phyllophoridae) (Martins 2019;Martins and Souto 2019).…”

Nomenclatural changes in some sea cucumbers with the erection of a new genus and description of a Thyone ?juvenile (?n. sp.) from the Gulf of California (Echinodermata:Holothuroidea:Dendrochirotida)

“…The calcareous ring is clearly like all East Pacific species of Thyone in being deeply cleft but the tentacle and introvert deposits indicate that the current specimen perhaps belong to a species not yet described. Since many holothuroids can lose or modify their deposits with age (see Thandar 1987, 1991, Massin 1992, Martins 2019, describing the single, perhaps juvenile individual as a new species is not here exercised. Although the body wall table discs may match those of Thyone bidentata Deichmann, 1941, known from California to Columbia, it differs in the spire of the tables and the absence of rosettes in the tentacles, unless by some stretch of imagination the minute plates were considered to be rosettes by Deichmann (1941) but regrettably they were not illustrated.…”

A new species of holothuroid from the Labrador Sea (eastern Canada): Pseudothyone labradorensis sp. nov. (Echinodermata, Holothuroidea, Dendrochirotida, Sclerodactylidae)

“…The original diagnosis by Panning (1949) included the following: ten tentacles, undivided pieces of calcareous ring and its radial pieces with two fork-shaped processes of medium length undivided or consisting of few large pieces, and body-wall ossicles composed of only plates. Later investigations of this genus added more variations to taxonomic characters ( Lambert and Oliver 2001 ; Martins 2019 ): tentacles ten equal-sized (in P. levini Lambert & Oliver, 2001) or eight bigger and two ventral smaller in all other species; body-wall ossicles smooth plates and knobbed buttons ( P. belli ), or smooth plates only (all other species); tube feet ossicles tables and end plates ( P. belli and P. mosaica ), rods and end plates ( P. sculponea Cherbonnier, 1958, P. serrifera (Östergren, 1898) and P. levini ), or end plates only ( P. raphanus and P. furnestini Cherbonnier, 1969); radial pieces of calcareous ring with short posterior processes ( P. levini ), or of medium length (all other species), with posterior processes undivided ( P. raphanus ), or divided into several pieces ( P. belli , P. mosaica , P. sculponea ).…”