Epiperipatus edwardsii ( Blanchard, 1847 )

Costa, Cristiano Sampaio, Chagas-Junior, Amazonas & Pinto-da-Rocha, Ricardo, 2018, Redescription of Epiperipatus edwardsii, and descriptions of five new species of Epiperipatus from Brazil (Onychophora: Peripatidae), Zoologia (e 23366) 35, pp. 1-15 : 2-4

Epiperipatus edwardsii ( Blanchard, 1847)

Figs 1–6

Peripatus edwardsii Blanchard, 1847: 140 .

Peripatus (Epiperipatus) edwardsii : Clark 1913: 18.

Epiperipatus edwardsii : Peck 1975: 345; Oliveira et al. 2012a: 10.

Diagnosis. The background color of the body of this species is in the purple spectrum; dorsal papillae round, primary papillae bearing asymmetrical apical piece, four complete spinous pads on the fourth and fifth legs (the last broken in some specimens).

Redescription. Measurements (mm): Type: length 35.0; width 4.0; height 3.0 (based on Bouvier 1905). Additional specimen (hereafter): length 30.0, width 3.0, height 3.0. Color (living specimen). Background color of body dark purplish gray (234), dorsal surface dark grayish reddish brown (47) with purplish gray (233) diamonds overlapping light brownish gray (63) dorsomedian furrow ( Fig. 2). Background color of ventral body purplish gray (233) with light gray and yellowish-brown (79) median band. Legs white (263) and ventral organs pale pink (7). Description of body. Conspicuous dorsomedial furrow and hyaline organs on entire length of body. Twelve plicae per segment, two incomplete (not extending to insertion of legs), and seven crossing over to ventral side. Uniform width among to the dorsal plicae as mentioned by Bouvier (1905). Dorsal papillae on all plicae ( Fig. 1). Primary papillae as the largest dorsal papillae, with roundish dome insertion and asymmetrical spherical apical piece ( Figs 1, 4). Basal piece larger than apical piece, with a range of at least seven scale ranks. Apical piece with three posterior scale ranks ( Fig. 4). Bristle directed posteriorly ( Fig. 4). Accessory papillae usually the smallest, but some as large as the basal piece of a primary papilla ( Fig. 1). Accessory papillae with roundish insertion. Accessory papillae more abundant than primary papillae per plica ( Fig. 1). Frequently, primary papillae separated by one to four accessory papillae. Dorsal papillae always on the plicae, although only and rarely accessory papillae present on flanks.

Head. No evident structures or color patterns on head. Antennae with 44 rings: antennal tip composed of seven broad rings, excluding the terminal disc on top. Antennal body with alternating sequence of narrow and broad rings at least up to the eighteenth. Eyes and frontal organs present on ventrolateral region of antennal base. Frontal organs as long as four fused antennal papillae. Mouth opening surrounded by small, anterior, unique lobe, and seven flanked lobes decreasing in size from anterior to posterior ends of the mouth. Dental formula of inner and outer jaws, respectively: 1/1 and 1/1/10, with second accessory tooth of inner jaw vestigial ( Fig. 5).

Legs. Male with 30 pairs of legs. Ventrally, fourth and fifth pairs of legs with four complete spinous pads (the fourth are sometimes broken) without vestige of fifth spinous pad ( Fig. 6). Nephridial tubercle on fourth and fifth pairs of legs, between third and fourth spinous pads, and connected at tip with third spinous pad ( Fig. 6). Two pro-lateral and one retro-lateral foot papillae the feet of fourth and fifth legs ( Fig. 3). Conspicuous ventral and preventral organs, gonopore close to penultimate pairs of legs in both sexes.

Sexual dimorphism. Male pregenital leg without crural papillae (these organs had not been previously described for this species). Anal glands inconspicuous (male); represented by two pores on ventral portion of anal aperture.

Material examined. 1♂, French Guiana, Cayenne , Nouragues Field Station , no further data (GF180312HC003-06). The holotype, deposited at the Muséum National d’Histoire Naturelle, Paris, France ( MNHN), was not examined because the curator did not reply to our loan requests .

Distribution. French Guyana: Cayenne and adjacency of Nouragues Field Station (Bélizon, Bita, Coco).

Remarks. The type of Epiperipatus edwardsii , deposited at the Muséum National d’Histoire Naturelle, Paris, France (MNHN) was not examined. We tried to contact the curator to arrange a loan of this material, but the curator did not reply. Epiperipatus edwardsii is the most frequently misidentified species of Epiperipatus and for this reason some records of its distribution (e.g., Brues 1914, Clark 1914, Peck 1975, Sampaio-Costa et al. 2009) are not accepted here. The shape and distribution of the dorsal papillae, dorsal diamond pattern and number of legs are frequently misinterpreted.

According to our observations, the diamond patterns are a general feature in most species of Epiperipatus . Morphologically, the diagnostic features to delimit E. edwardsii are (1) dorsal papillae over the plicae and never on the folds, and (2) primary papillae usually separated by one or two accessory papillae (however in some cases they are close to each other). Also, E. edwardsii is supported by molecular data as demonstrated in Maximum Parsimony and Maximum Likelihood analyses (e.g., Costa (2016) and Giribet et al. 2018).

The other records of E. edwardsii found in the literature, for instance from Panama, Venezuela, Colombia and Brazil ( Brues 1914, Clark and Zetek 1946, Read 1988a, b, Sampaio-Costa et al. 2009, see discussion below) are probably based on undescribed species. Moreover, records of E. edwardsii from Aripo in Trinidad ( Read 1988a) and Haut Sarare, Venezuela ( Read 1988b) also correspond to an undescribed species. In conclusion, the distribution of E. edwardsii is likely limited to French Guyana.