This velvet worm was first described briefly by the biologistW. Baldwin Spencer in a note written in 1894 but published in 1895. He based his description on fifteen specimens, which he found in 1893 under fallen logs on Mount Wellington in Tasmania. He assigned these specimens to the species Peripatus insignis, a similar velvet worm discovered earlier in the state of Victoria on the Australian mainland.[4] Similarly, after proposing the genus Ooperipatus in 1900 to contain all oviparous velvet worms,[9][10] the English zoologistArthur Dendy assigned the Tasmanian specimens described by Spencer to Ooperipatus insignis.[6]
In 1907, the French zoologistEugène Louis Bouvier described this Tasmanian velvet worm in more detail as a species distinct from the mainland species but nevertheless applied the name Ooperipatus insignis to the Tasmanian species.[5] In 1913, in a footnote in an article by the American zoologist Austin Hobart Clark, the American biologist Theodore D.A. Cockerell proposed the name Ooperipatus spenceri for this Tasmanian velvet worm as a distinct species.[11] Nevertheless, in 1977, the German zoologist Martin Baehr deemed O. spenceri to be a junior synonym of O. insignis.[12] Similarly, in 1985, the German zoologist Hilke Ruhberg proposed the genus Ooperipatellus to include a subset of the oviparous velvet worms, including O. insignis, but she also assigned the Tasmanian specimens described by Spencer and Bouvier to O. insignis.[13] Authorities now recognize O. spenceri and O. insignis as distinct species, however, noting the significant distance (652 km) between the type localities of these two species and their separation by the Bass Strait.[8][14]
Description
Adults in this species can range from 9 mm to 23 mm in length and from 1 mm to 4 mm in width, with the males generally smaller than the females.[4][5] The jaw features two blades, an inner blade and an outer blade. The inner blade features one large tooth, four to seven smaller accessory teeth, and no diastema. The outer blade features only one large tooth with no accessory teeth. This velvet worm features 14 pairs of legs.[5] The dorsal surface of the body features 12 complete plicae (transverse ridges) per segment. Each foot features three spinous pads and three distal papillae, but no basal papillae.[12] The male of this species features crural papillae on leg pairs 6 through 13.[15][5] The female features an ovipositor as large as the legs of the last leg pair.[12]
This species varies widely in color, ranging from dark purplish black specimens with only faint traces of a pattern to others with more orange-red, a dark line down the middle, and marked patterns.[4][5] The ventral surface of the body and the inner surfaces of the legs are pale, but the ventral surface can feature two broad dark longitudinal stripes in some specimens. The proximal and middle spinous pads are mostly brownish yellow, but the distal pad and the distal and lateral edges of the middle pad are blue. The oral papillae are white.[12] The antennae are brownish but blue at the distal ends and can feature a few orange rings. The eyes are white or a pale blue.[12][5]
Phylogeny
In 2025, a specimen previously identified as an undescribed species of Ooperipatus was identified as O. spenceri.[16] This specimen has provided genetic data used in multiple phylogenetic studies published earlier.[17][7][18] Given this 2025 identification, for example, a 2017 phylogenetic analysis based on molecular data places O. spenceri (Ooperipatellus sp. 5) in a clade with another Tasmanian species in the same genus, O. nickmayeri, indicating that O. spenceri is more closely related to O. nickmayeri than to the other two Tasmanian species in the same genus (O. cryptus and O. decoratus) and the mainland species O. insignis, three species that together form a separate clade. The type localities of O. spenceri and O. nickmayeri are more than 88 km apart, and the molecular evidence separates these two velvet worms on relatively long branches in a phylogenetic tree, suggesting that these two close relatives are distinct species.[7]
Distinguishing these two close relatives based on morphology requires more information from a comprehensive revision of O. spenceri. These species might be distinguished based on the spinous pads on the feet, for example, which are whitish or pale orange in the species O. nickmayeri.[7] In the species O. spenceri, these pads are mostly brownish yellow, but the distal pad and the distal and lateral edges of the middle pad are blue.[12] Furthermore, the oral papillae are orange or tan in O. nickmayeri but white in O. spenceri.[7][12] Little is known, however, about intraspecific variation in these color patterns in O. spenceri.[7]
1 2 3 4 5 6 7 8 Baehr, Martin (1977). "Über einige Onychophoren aus Australien und Tasmanien mit Beschreibung einer neuen Art und Anmerkung zur Stellung von Ooperipatus paradoxus Bouvier, 1915". Zoologische Jahrbucher. Abteilung fur Systematik, Geographie und Biologie der Tiere (in German). 104: 9–19.
↑ Ruhberg, Hilke (1985). Die Peripatopsidae (Onychophora): Systematik, Ökologie, Chorologie und phylogenetische Aspekte. Zoologica (in German). Stuttgart: Schweizerbart. pp.126–128. ISBN978-3-510-55023-4.
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