Taxonomic Notes on Mesoperipatus Tholloni (Onychophora: Peripatidae), an Elusive Velvet Worm from Gabon

Taxonomic Notes on Mesoperipatus tholloni (Onychophora: Peripatidae), an Elusive Velvet Worm from Gabon

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Citation Costa, Cristiano S., and Gonzalo Giribet. 2016. “Taxonomic Notes on Mesoperipatus Tholloni (Onychophora: Peripatidae), an Elusive Velvet Worm from Gabon.” Breviora 552 (1) (December): 1–10. doi:10.3099/mcz30.1.

Published Version doi:10.3099/MCZ30.1

Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:34872762

Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Other Posted Material, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#LAA US ISSN 0006-9698

CAMBRIDGE,MASS.N14 DECEMBER 2016 UMBER 552

TAXONOMIC NOTES ON MESOPERIPATUS THOLLONI (ONYCHOPHORA: PERIPATIDAE), AN ELUSIVE VELVET WORM FROM GABON 1,2 1 CRISTIANO S. COSTA AND GONZALO GIRIBET

ABSTRACT. The velvet worm Mesoperipatus tholloni (Bouvier, 1898) is among the least understood of the velvet worms, the only species in the genus Mesoperipatus Evans, 1901, and the only African Peripatidae. Despite its biogeographic and phylogenetic uniqueness, originally thought to be an intermediate between Peripatidae and Peripatopsidae, little work has been published since its original treatment in a series of papers in the late 1800s and early 1900s. Here, we provide a redescription of this species based on new material collected during a 2009 Museum of Comparative Zoology (MCZ) expedition to Gabon and examination of historical material from the original collections lodged at the MCZ and the Museu de Zoologia, Universidade de Sa˜o Paulo (MZUSP). We also provide the first scanning electron micrographs of this species.

KEY WORDS: taxonomy; morphology; Africa; scanning electron microscopy

INTRODUCTION Peripatidae (Bouvier, 1898a; Evans, 1901; Oliveira et al., 2012). The first specimens of Mesoperipatus tholloni (Bouvier, 1898) is this rare species (two females) were collected by among the least understood of the velvet French botanist and chief of exploration of the worms, the only species in the genus Mesoper- French Congo, M. Thollon, who died in ipatus Evans, 1901, and the only African Libreville on January 1897. The specimens were described by Bouvier (1898b), who erected 1 Departamento de Zoologia, Instituto de Biociencias,ˆ the new species Peripatus tholloni as a ‘‘transi- Universidade de Saõ Paulo. Rua do Mataõ, Travessa 14, no. 321, Cidade Universita´ria, SaõPaulo,SP, tional form’’ between the South African Brazil; e-mail: [email protected]. peripatopsids and the American peripatids 2 Museum of Comparative Zoology, Department of (Bouvier, 1898c; see also Bouvier, 1898d). In Organismic and Evolutionary Biology, Harvard his original description, Bouvier (1898b) men- University, 26 Oxford Street, Cambridge, Massachusetts 02138, USA; e-mail: ggiribet@g. tioned Gabon as the type locality, but subse- harvard.edu. quent papers and collection labels often refer to

Ó The President and Fellows of Harvard College 2016. 2 BREVIORA No. 552

Congo or French Congo.1 The two original N’Djole,´ and near Samba (Schweitzer and specimens collected by Thollon were split Campion, 1923). between the Museum´ national d’Histoire na- Bouvier (1904) specified that E. Haug made turelle, Paris, and the Cape Museum (now the available five specimens, including an adult Iziko South African Museum, Cape Town) male—the only one known until then for the (Bouvier, 1905:349). species. All the known specimens are listed in Later in 1903, Mr. Haug, a pastor and Bouvier’s monograph (1905): the two original naturalist, sent Bouvier two additional spec- females collected by Thollon, the first two imens collected on 15 March (Haug, 1903). females collected by Haug, and four additional females and one male collected by Haug in The letter was sent from Ngomˆ o,ˆ on the 1904. It is however possible that some of these Ogooue´ River, which was subsequently specimens do not belong to the same species, interpreted as the collection locality. Oliveira given the variation in the number of legs et al. (2012) said that the modern name of 2 reported in the redescription of the species Ngomˆ oˆ is Ngole,´ but this is unlikely, as (Bouvier, 1905). Later, in the catalogue of the both are close localities in the Moyen- onychophorans of the Museum´ national d’His- Ogooue´ Province, Ogooue´ et des Lacs toire naturelle (MNHN), Bouvier (1907a) lists Department: Ngomˆ oˆ (0.848S, 9.988E) and the collecting date of the Thollon specimens Ngole´ (0.838S, 10.078E) (Fig. 1) (Falling (1883) and specifies that only one of the two Rain Software Ltd., 1996–2016). Both local- original specimens from Thollon and one of the ities have existed for over a century, as two first specimens from Haug remained in the evidenced in Schweitzer’s impressions and MNHN. In that paper it is also made clear that experiences in Gabon, where he described the type locality is Gabon and cites additional several of the settlements of the time specimens from Ngomˆ oˆ collected by Haug in (Schweitzer and Campion, 1923). Schweitzer 1906. In addition to these, new ‘‘beautiful’’ was sponsored by the Paris Evangelical specimens from ‘‘Talagonga, near N’Djole’’´ Missionary society, which had taken over were collected in 1906 by Ellenberger—another four stations established by American Prot- missionary working in Gabon. It is therefore estants: these were at N’Gomo,ˆ 3 Lambarené,´ not improbable that this whole suit of specimens represents more than one species. Sakita, and Talagonga; Catholics, mean- A large female and a small male from the while, were established at Lambarené,´ 1906 collections from Talagonga were do- 1 The French Congo, which began at Brazzaville on 10 nated by the MNHN to the Museum of September 1880 as a protectorate over the Bateke Comparative Zoology, Harvard (MCZ) people along the north bank of the Congo River, was (‘‘Talagonga pres` de N’Djole,´ Ellenberger formallyestablishedastheFrenchCongoon30 capt.’’; however, on the label, it also says November 1882 and was confirmed at the Berlin Conference of 1884–85. The French Congo was ‘‘Ogooue,´ E. Haug’’). An additional large sometimes known as Gabon-Congo. It formally female and small male from ‘‘pre` de N’Djole,´ added Gabon on 30 April 1901, was officially dans l’Ogooue’’´ were also donated to the renamed Moyen-Congo in 1903, was temporarily Museu de Zoologia, Universidade de Saõ divorced from Gabon in 1906, and was then reunited Paulo (MZUSP), ‘‘capt. Par M. Ellenberger as French Equatorial Africa in 1910. pour M. Haug.’’ It could be that the 2 Ngole´ is a town from the Ogooue´ et des Lacs Department (Lambar.) (08500S, 108040E), Moyen specimens from the MCZ and from the Ogooue,´ Gabon. MZUSP are a mixed lot from the Haug 3 Another spelling for Ngomˆ o.ˆ 1906 and the Ellenberger 1906 collections. 2016 TAXONOMIC NOTES ON MESOPERIPATUS THOLLONI 3

Figure 1. Map of the Middle Ogooue´ river section, with the traditional localities of Ngomˆ oˆ and Ndjole´ (yellow stars), and the newer collection point west of Lambaren´e´ (red star). Inset shows the larger region, and the red square identiﬁes the studied region.

Although Talagonga was the ‘‘most ad- things. More recent specimens collected in vanced mission station’’ in the late 1800s January 1970 have been reported from Came- and early 1900s, it is not found on modern roon (Senckenberg Naturmuseum, Frankfurt). maps but was located in the rapids of the In addition to the historical specimens in Ogooue´ river, near Ndjole´ (in modern the MCZ a modern expedition to Cameroon spelling). These specimens are thus found and Gabon yielded an additional specimen quite a distance from the former ones from of this species (or species complex). The the Abanga-Bigne Department of the Moy- specimen was collected by L. R. Benavides, en-Ogooue´ Province. G. Giribet, and J. Y. Muriene near Few authors actually studied this species Lambarené,´ in the Moyen-Ogooue´ Province, after Bouvier (but see Fedorow, 1926, 1929) Ogooue´ et des Lacs Department, on 28 June because of the difficulties in obtaining fresh 2009. This specimen was used for molecular material from this genus endemic to the forests study by Murienne et al. (2014), but none of of the Moyen-Ogooue´ Province, among other the MCZ specimens—old or new—were 4 BREVIORA No. 552 studied morphologically. Here we provide of the left side, and a small rectangular the first scanning electron micrographs for section of the dorsal integument covering this specimen and provide a redescription of from the dorsomedian furrow to the base of some salient characters of M. tholloni. the oncopods were dissected out and prepared for SEM. Additionally, from female MATERIALS AND METHODS specimen MCZ IZ-85892, a piece of the dorsal integument was dissected out and The five specimens available in the MCZ prepared for SEM. These tissues were critical and MZUSP were examined morphological- point dried and mounted in SEM stubs with ly and compared with the original descrip- biadhesive carbon tape. The samples were tion of M. tholloni (Bouvier, 1898a) on the then sputter coated with an EMS 300T D basis of specimens from a single locality and the monographs written by Bouvier (1905, dual-headed sputter coater at the Harvard 1907b), in which he redescribed the species Center for Nanoscale Systems. A 5-nm on the basis of specimens from multiple platinum/palladium layer was applied. Sam- localities. Two specimens were studied using ples were imaged with a Carl Zeiss Ultra Plus scanning electron microscopy (SEM). FESEM using the SE2 and backscatter Material Examined. MCZ IZ-85892: One detectors. Images were then edited using male and one female in 70% EtOH from Adobe Photoshop CS5. Talagonga, near N’Djole,´ Ogooue,´ Gabon, collected in 1906 (no exact collection data); Coloration ‘‘Ellenberger capt.’’ and ‘‘E. Haug’’ appear Photographs of a life specimen were taken on the original label. Female specimen with a Nikon D2X digital camera equipped studied under SEM (images not shown, as with an AF-S Micro Nikkor 60 mm f/2.8D ED the specimen was in bad shape). or with an AF-S Micro Nikkor 105 mm f/2.8D MCZ IZ-131381: One female in 96% ED lens and a TTL Nikon Speedlight. Color- EtOH from near Lambarené´ (0.658248S, ation was described from the photographs of 10.199168E), Moyen-Ogooue´ Province, Ga- the living specimen (Figs. 2–4). Standard names bon; Leg. L. R. Benavides, G. Giribet, and J. of the 267 Color Centroids of the NBS/ISCC Y. Murienne, 28.vi.2009. Specimen used for Color System (Mundie, 1995) were used in molecular work (Murienne et al., 2014) and descriptions and given in parentheses. prepared for SEM. MZUSP: One male and one female in 70% TAXONOMIC RESULTS EtOH (no catalogue number) from near Family Peripatidae Evans, 1901 N’Djole,´ Ogooue,´ Gabon, no collection Genus Mesoperipatus Evans, 1901 data; ‘‘capt par Ellenberger pour E. Haug’’ Mesoperipatus tholloni (Bouvier, 1898) appears on the original label. Figures 2–10 Dental formula and descriptive terminol- ogy follow the onychophoran literature, Peripatus tholloni Bouvier, 1898a:197; Bouv- most importantly Bouvier (1898a, 1905) ier, 1905:337. and Evans (1901). Mesoperipatus tholloni (Bouvier, 1898): Evans (1901:478). SEM imaging Emended diagnosis. Broad and narrow From specimen MCZ IZ-131381, one dorsal plicae alternating throughout the antenna, one mandible, the fifth oncopod dorsal region with clear differences in the 2016 TAXONOMIC NOTES ON MESOPERIPATUS THOLLONI 5

Figures 2–4. Live female of Mesoperipatus tholloni. Figure 2. Whole animal in dorsal view. Figure 3. Anterior part of the animal in dorsolateral view. Figure 4. Ventral side with spinous pads in detail. 6 BREVIORA No. 552 number of dorsal papillae between the two primary papillae only occur on the broad types of dorsal plicae. Dorsal papillae plicae (Figs. 6, 7). In all plicae, the primary varying in size, the biggest ones being only papillae are always separated by accessory present on the broader plicae. Roundish papillae, and the number of papillae on the dorsal papillae close together, and primary large plicae is larger than on the narrow papillae with an asymmetric apical piece plicae (Fig. 6). On the broader plicae, the with the bristle directed posteriorly. Both accessory papillae occur on the top or ﬂanks jaws with one accessory tooth; the inner jaw of the plicae, although on the narrow plicae, also armed with ten denticles separated from the dorsal papillae only occur on the top the accessory teeth by a diastema. From tip (Fig. 6). Largest primary papillae with to base, the antenna has six broad rings roundish insertion dome or conical base followed by a narrow ring, then changing to and asymmetrical spherical apical piece alternating rings until about the 30th ring. (Figs. 6, 7). Basal piece larger than apical Two crural papillae present on the two piece, with around eight scale ranks (Fig. 7). pregenital legs of the male. Apical piece with three or four anterior and two or three posterior scale ranks (Fig. 7). Description of the studied specimens The scales are robust on the base and thinner on the apical piece (Fig. 7). Bristles on the Measurements (length/width/height in examined material were broken on the mm). Female IZ-13181: 30/4.5/1.4; Female majority of primary papillae, probably IZ-85892: 40/4.0/3.0; Female MZUSP: 55/ caused by cryopreservation (Fig. 7). Smallest 3.0/4.0; Male IZ-85892: 14/0.05/0.05; Male primary papillae with the base and apical MZUSP: 15/1.0/1.0. piece not clearly distinguished. Accessory Color (for living specimens; Figs. 2–4). papillae similar in shape to the base of the Dorsal body background light reddish smaller primary papillae, but smaller in size brown (42) with dorsal light spots (primary and higher in number (Fig. 6). papillae) grayish yellowish pink (10). With- No evident structures or patterns on the out dorsal patterning, with dorsomedian head. Antennae with an interesting pattern furrow, brownish grayish brown (61). Head of ring distribution (Figs. 2–4, 9); composed color as body background and antennae of 50 rings on both sexes. The antennal tip grayish yellowish brown (80). Dorsal side of composed of six broad rings, excluding the legs grayish pink (8), ventral body back- disc on the top, followed by a sequence of ground moderate pink (5), with sparser, thin and broad rings until at least ring 31 light papillae pale purplish blue (202) (Figs. (Fig. 9). Eyes and frontal organs present 2, 3). Ventral organs pinkish white (9) and ventrolateral of the antennal base. Frontal spinous pad light greenish gray (154) (Fig. organs with length equivalent to three to ﬁve 4). fused antennal papillae. Body description. Dorsum: dorsomedian Venter: Mouth opening surrounded by furrow clearly visible; hyaline organs absent. seven lobes in a decreasing sequence from With 12 broad plicae per segment, incom- front to posterior ends of the mouth; all of plete plicae absent, narrow and broad plicae them with small spines on the top, as detailed alternating for all dorsal integument, seven by Bouvier (1905:341). Inner and outer jaw of which cross over to the ventral side (Fig. blades both with one, long primary tooth 5). Primary and accessory papillae present followed by a small accessory tooth (Fig. 8). on both plicae (Figs. 5, 6), but the largest On the inner blade, a diastema separates the 2016 TAXONOMIC NOTES ON MESOPERIPATUS THOLLONI 7

Figures 5–7. SEM images of dorsal integument and jaws. Figure 5. Section of the dorsal integument corresponding to one segment on the middle of the body; note the lack of incomplete plicae. Figure 6. Detail of the dorsal broad (yellow) and narrow plicae. Figure 7. Primary papilla on dorsal view. Figure 8. Jaws of the left mandible, outer jaw in front. Inner jaw (back) with 10 denticles; the first, near the diastema, is broken, and the last is hidden on this image. 8 BREVIORA No. 552 accessory tooth from a series of at least 10 graphic distribution (Bouvier, 1898a, d; denticles (Fig. 8). The inner and outer blade Monge-Na´jera, 1995) and morphology formulas are 1/1 and 1/1/10, respectively (Evans, 1901; Bouvier, 1905) or to constitute (Fig. 8). Females with 25 or 26 pairs of legs a ‘‘link’’ between both groups based on (Fig. 2); 24 in males; usually with three phylogenetic placement using molecular data complete and sometimes with vestiges of a (Murienne et al., 2014), which severed fourth spinous pad, without evidence of a connections to the South American fauna fifth (Fig. 10). after the Lower Cretaceous (Monge-Na´jera, Nephridial tubercle occurring on the 1995) or around the Triassic (Murienne et fourth and fifth legs, connected on top with al., 2014). the third spinous pad and between two Moreover, the morphology of M. tholloni fragments of the fourth spinous pad (Fig. is singular and easy to recognize because the 10). Two prolateral and one retrolateral foot genus has three complete and a vestige of a papillae in the feet of the fourth and fifth fourth spinous pad on the fourth and fifth legs. Ventral and preventral organs not legs and a random distribution (on the top or examined. Genital opening located close to furrow) of the accessory papillae in alternat- penultimate pair of legs in both sexes, as in ing dorsal papillae. Despite the anal gland all species of Peripatidae, opening in a crux, ducts opening in a single and large orifice, and usually surrounded by tumescent lobes like Eoperipatus (also observed in some higher than the ventral integument. Only two Oroperipatus), Mesoperipatus differs from pregenital legs with crural papillae (male) Eoperipatus in the number of broad rings with one crural papilla each. Anal glands on the tip of the antennae and on the number inconspicuous (male); represented only by of complete spinous pads and foot papillae the respective single pore on ventral part of on the fourth and fifth leg pairs. anal aperture. Similar to some Neotropical Peripatidae, Type locality.Ngomˆ o,ˆ Moyen-Ogooue,´ M. tholloni has alternating broad and Gabon. narrow plicae on its dorsal integument, such Distribution. Province Lambarené,´ Tala- as Oroperipatus ecuadorensis (Bouvier, 1902). gonga, Moyen-Ogooue,´ Gabon; coordinates Some dorsal plicae of M. tholloni could be 0.658248S, 10.199168E (Fig. 1). misidentified as incomplete dorsal plicae, because they may result from some anasto- DISCUSSION mosed regions of the dorsal plicae. The number of accessory teeth on both Since the first records of the species, jaws, the number of foot papillae, and the Mesoperipatus tholloni has been easy to absence of incomplete plicae are shared recognize because of its unique geographic characteristics between Mesoperipatus and distribution, being the only African Peripa- the four most speciose genera of Onycho- tidae. This unique distribution (only known phora in Central and South America. from the Moyen-Ogooue´ Province and Despite historical debate about the place- Cameroon) and its monotypy make this ment of M. tholloni in the family Peripatidae, interesting genus even more important. our study of the external morphology of this Mesoperipatus tholloni has been hypothe- species confirms that it is a unique Peripati- sized to be an intermediate group between dae species from the African continent, which the American and Asian groups of ony- seems to share external characteristics with chophorans because of their unique biogeo- Asian and American peripatids. The stron- 2016 TAXONOMIC NOTES ON MESOPERIPATUS THOLLONI 9

Figures 9, 10. SEM images of antenna and spinous pads. Figure 9. Left antenna; inset showing the tip of the antenna with six broad rings until interrupted by one thin ring (arrow). Figure 10. Spinous pads of the fifth leg, left side. Complete spinous pads I and III are labeled; the fourth spinous pad is formed by fragments. Urinary papilla (p) connected with third spinous pad. 10 BREVIORA No. 552 gest evidence for this placement is the anal BOUVIER, E.-L. 1904. Sur les organes genitaux´ malesˆ du gland opening, the distribution of dorsal Peripatus Tholloni Bouv. [Onych.]. Bulletin de la papillae on the plicae, and the number of Societ´ e´ entomologique de France 1904: 192–193. BOUVIER, E.-L. 1905. Monographie des Onychophores. spinous pads on the fourth and fifth legs. This Annales des Sciences Naturelles, Zoologie 2: 1–383. placement is also corroborated by molecular BOUVIER, E.-L. 1907a. Catalogue des Onychophores des analyses (Murienne et al., 2014), which show collections du Museum´ d’histoire naturelle de Paris. that in spite of shared characteristics with Bulletin du Museum National d’Historie Naturelle Asian onychophorans, M. tholloni is more 13: 518–521. closely related to the Neotropical forms BOUVIER, E.-L. 1907b. Monographie des Onychophores. (Murienne et al., 2014); it is intermediate in Annales des Sciences Naturelles, Zoologie 5: 61–318. position between these two biogeographical EVANS, R. 1901. On two new species of Onychophora from the Siamese Malay States. Quarterly Journal regions, making this species integral in studies of Microscopical Science 44: 473–538. of Peripatidae evolution. FALLING RAIN SOFTWARE LTD. 1996–2016. Directory of Cities and Towns in Moyen-Ogooue, Gabon [Internet]. ACKNOWLEDGMENTS Alton, Hampshire (UK): Falling Rain Software Ltd.; [2016, cited 20XX MON XX]. Available from: http:// Ligia Benavides and Jerome Murienne www.fallingrain.com/world/GB/03/index.html. accompanied GG during the 2009 expedition FEDOROW, B. 1926. Zur Anatomie des Nervensystems to Cameroon and Gabon. Collecting permits von Peripatus. I. Das Neurosomit von Peripatus were kindly provided by Jacques F. Ma- tholloni. Zoologische Jahrbucher,¨ Abteilung fur¨ voungou and the Institut de Recherche en Anatomie und Ontogenie der Tiere 48: 273–310. Ecologie Tropicale (CENAREST). Field- FEDOROW, B. 1929. Zur Anatomie des Nervensystems work was supported by a Putnam Expedi- von Peripatus. II. Das Nervensystems des vorderen Ko¨rperendes und seine Metamerie. Zoologische tion Grant of the MCZ. Beka Buckman and Jahrbucher,¨ Abteilung fur¨ Anatomie und Ontogenie Julia Cosgrove provided help and comments. der Tiere 50: 279–332. C.S.C. was partially supported by Saõ Paulo HAUG,E.1903.Sur le Peripatus tholloni. Extrait d’une Research Foundation (FAPESP) grants lettre adressee´ de Ngomˆ o(Ogˆ oouˆ e)´ par M. le Pasteur 2011/20211-0, 2012/02969-6, and 2014/ Hauga` M. LeProfesseur Bouvier. Bulletin du Museum´ 20557-2. We acknowledge the support of National d’Histoire Naturelle, Paris 9: 221–222. the Center for Nanoscale Systems, Harvard MONGE-NA´JERA, J. 1995. Phylogeny, biogeography and University, for the SEM images. reproductive trends in the Onychophora. Zoologi- cal Journal of the Linnean Society 114: 21–60. MUNDIE, D. A. 1995. The NBS/ISCC Color System LITERATURE CITED [Internet]. Pittsburgh (Pennsylvania): Polymath BOUVIER, E.-L. 1898a. Sur l’organisation du Peripatus Systems 535.6 dc-20; Available from: http://www. Tholloni, Bouv. Bulletin de la Societ´ e´ entomologique anthus.com/Colors/Cent.html. de France 1898: 197–198. MURIENNE, J., S. R. DANIELS,T.R.BUCKLEY,G.MAYER, BOUVIER, E.-L. 1898b. Note preliminaire´ sur la distri- AND G. GIRIBET. 2014. A living fossil tale of bution geographique´ et l’evolution´ des Peripates.´ Pangaean biogeography. Proceedings of the Royal Comptes Rendus Hebdomadaires des Seances´ de Society B: Biological Sciences 281: 2013–2648. l’Academie´ des Sciences 126: 1358–1361. OLIVEIRA, I. de S., V. M. St J. Read, and G. Mayer. BOUVIER, E.-L. 1898c. New observations on Peripatus. 2012. A world checklist of Onychophora (velvet Annals and Magazine of Natural History (series 7) worms), with notes on nomenclature and status of 2: 354–355. names. ZooKeys 211: 1–70. BOUVIER, E.-L. 1898d. On the geographical distribution SCHWEITZER, A., AND C. T. CAMPION. 1923. On the Edge and the evolution of Peripatus (preliminary note). of the Primeval Forest; Experiences and Observa- Annals and Magazine of Natural History (Series 7) tions of a Doctor in Equatorial Africa. London: A. & 2: 351–353. C. Black.