​A review of pygal-furrowed Synallactidae (Echinodermata: Holothuroidea), with new species from the Antarctic, Atlantic and Pacific oceans

P. Mark O'Loughlin and Cynthia Ahearn

Memoirs of Museum Victoria Vol 62 (2) p. 147–179 (2005)



We review the genera and species of pygal-furrowed Synallactidae and describe new species from the collections ofthe United States National Museum of Natural History (Smithsonian Institution). Meseres Ludwig is reviewed and placed incertae sedis. Molpadiodemas Heding and Pseudostichopus Théel are rediagnosed. Platystichopus Heding is declared a junior synonym of Molpadiodemas. Filithuria Koehler and Vaney and Peristichopus Djakonov are declared junior synonyms of Pseudostichopus. Lectotypes are designated for: Meseres involutus Sluiter, M. macdonaldi Ludwig, M. peripatus Sluiter, Pseudostichopus globigerinae Hérouard, P. mollis Théel, P. pustulosus Sluiter, P. trachus Sluiter, P. villosus Théel. A neotype is designated for Pseudostichopus nudus Ohshima.

Except for the type species, Meseres macdonaldi Ludwig, and Meseres (?) torvus (Théel), all species previously referred to Meseres are reassigned to Molpadiodemas or Pseudostichopus. Meseres (?) torvus (Théel) is retained in its original combination. Eleven new synallactid species are described: Molpadiodemas constrictus, M. crinitus, M. epibiotus, M. helios, M. morbillus, M. neovillosus, M. pediculus, M. porphyrus, M. translucens, M. ustulatus and Pseudostichopus tuberosus. Molpadiodemas constrictus is fissiparous. Pseudostichopus villosus var. violaceus Théel is raised to species status; Pseudostichopus alatusImaoka, P. trachus Sluiter and P. nudus Ohshima are junior synonyms of Pseudostichopus mollis Théel; Pseudostichopus globigerinae Hérouard and P. dilatorbis Imaoka are junior synonyms of Meseres (= Molpadiodemas) involutus Sluiter; Pseudostichopus propinquus Fisher and P. lapidus Hérouard are junior synonyms of Meseres (= Pseudostichopus) peripatus Sluiter; and Pseudostichopus arenosus Ohshima and P. molpadioides Ohshima are junior synonyms of Meseres (= Pseudostichopus) hyalegerus Sluiter.

New combinations are: Molpadiodemas atlanticus (Perrier), M. depressus (Hérouard), M. involutus (Sluiter), M. pustulosus (Sluiter), M. villosus (Théel), Pseudostichopus elegans (Koehler and Vaney), P. hyalegerus (Sluiter), P. papillatus (Djakonov), P. peripatus (Sluiter) and P. spiculiferus (O'Loughlin). Other species discussed are: Molpadiodemas violaceus (Théel), Pseudostichopus aemulatus Solís-Marín and Billett, P. echinatus Thandar, P. mollis Théel, P. occultatus Marenzeller, and P. profundi Djakonov. A key is provided for the species of Molpadiodemas and Pseudostichopus. Tables are provided of genera and subgenera with current systematic status, and species with original and current combinations.


O'Loughlin, P.M. & Ahearn, C., 2005. A review of pygal-furrowed Synallactidae (Echinodermata: Holothuroidea), with new species from the Antarctic, Atlantic and Pacific oceans. Memoirs of Museum Victoria 62: 147-179. http://doi.org/10.24199/j.mmv.2005.62.5


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