Martiodrilus (Botaria) flavus Decaëns & Bartz, 2024

Decaëns, Thibaud, Bartz, Marie Luise Carolina, Bartz, arolina, Feijoo-Martínez, Alexander, Goulpeau, Arnaud, Lapied, Emmanuel, Marchán, Daniel F., Maggia, Marie-Eugénie, Papuga, Guillaume & James, Samuel W., 2024, Earthworms (Oligochaeta, Clitellata) of the Mitaraka range (French Guiana): commented checklist with description of one genus and eighteen species new to science, Zoosystema 46 (9), pp. 196-244 : 204-206

Martiodrilus (Botaria) flavus Decaëns & Bartz , n. sp.

( Figs 2F ; 6 )

urn:lsid:zoobank.org:act:72B28D19-6D97-473A-924C-8053998DF36F

TYPE MATERIAL. — Holotype. French Guiana • Adult (with posterior regeneration); Tumuc-Humac, Mitaraka Massif , transition forest on DIADEMA project C trail, in decaying trunk; 2°14’19”N, 54°26’6”W; 389 m a.s.l.; III.2015; T. Decaëns, E. Lapied leg.; BOLD Sample ID: EW-MI15-0001 ; MNHN.

Paratypes. French Guiana • 3 adult specimens; Tumuc-Humac, Mitaraka Massif , plateau forest on DIADEMA project D trail; 2°12’57”N, 54°27’25”W; 381 m a.s.l.; III.2015; T. Decaëns, E. Lapied leg.; BOLD Sample ID: EW-MI15-0008 , EW-MI15-0009 , EW-MI15-0010 ; CEFE • 2 adult specimens; Tumuc-Humac, Mitaraka Massif , slope forest on trail to Sommet en Cloche Inselberg ; 2°14’6”N, 54°27’11”W; 352 m a.s.l.; III.2015; T. Decaëns, E. Lapied leg.; BOLD Sample ID: EW-MI15-0358 , EW-MI15-0359 ; MNHN.

OTHER MATERIAL EXAMINED. — French Guiana • 1 juvenile specimen; Tumuc-Humac, Mitaraka Massif , plateau forest at base camp; 2°14’2”N, 54°27’1”W; 331 m a.s.l.; III.2015; T. Decaëns, E. Lapied leg.; BOLD Sample ID: EW-MI15-0175 ; MNHN • 1 juvenile specimen, 8 cocoons; Tumuc-Humac, Mitaraka Massif , plateau forest on DIADEMA project D trail; 2°12’57”N, 54°27’25”W; 381 m a.s.l.; III.2015; T. Decaëns, E. Lapied leg.; BOLD Sample ID: EW-MI15-0024 , EW-MI15-0028 , EW-MI15-0012 , EW-MI15-0013 , EW-MI15-0014 , EW-MI15-0015 , EW-MI15-0016 , EW-MI15-0017 , EW-MI15-0018 ; MNHN.

ETYMOLOGY. — This species is named in reference to the remarkable yellow pigmentation of the body observed in most adult specimens.

ECOLOGY. — Martiodrilus (B.) flavus Decaëns & Bartz , n. sp. was predominantly found in plateau forests (81.25% of specimens) and other well-drained habitats such as slope forests (12.5%) and transition forest at the edge of rocky savannah (6.25%) ( Fig. 6G ). It preferentially inhabits under large decaying trunks fallen at the soil surface (81.25%), but was also occasionally found within the soil (18.75%) ( Fig. 6H ). Cocoons are tan yellow, spherical, 15-20 mm in diameter, with marked mucrons at the anterior and posterior ends.

DISTRIBUTION. — Martiodrilus (B.) flavus Decaëns & Bartz , n. sp. is known from the Mitaraka Massif.

DESCRIPTION

External morphology ( Fig. 6A, B )

Body shape cylindrical. Body pigmentation yellow when alive ( Fig. 2F ) sometimes with a transition to grey toward the tail and in regerating parts of the body, clitellum pink when alive, dark beige after ethanol fixation. Body length: 285 mm in the holotype, 265 to 300 mm in the paratypes (average: 283.3 mm; n = 3), after ethanol fixation. Body mass: 21.32 g after ethanol fixation in the holotype, 15.45 to 23.70 g in the paratypes (average: 20.56 g; n = 3). Diameter: 9.3 to 12.5 mm in the preclitellar region, 12.2 to 13 mm in the clitellum, 10.5 to 13 mm in the postclitellar region. Number of segments: 234 in the holotype, 245 to 264 in the paratypes (average: 254.7; n = 3). Prostomium proepilobic. Setae closely paired, ab and cd beginning in III or IV. Setal arrangement aa:ab:bc:cd:dd = 10:1:12:1:34. Clitellum in (½ XIII) XIV-½ XXVI, saddle-shaped ( Fig. 6A ). Genital markings in V-XIII, intraclitellar in XIV-XXIV (ab position). Tubercula pubertatis linear in XIX-XXV ( Fig. 6B ). Male pores not recognised, and ovipores in XIV, anterior and slightly dorsal to b. Spermathecal pores in 5/6, 6/7 and 7/8, in line of ab. Nephridial pores begining in III-IV, in D line.

Internal anatomy ( Fig. 6 C-F)

Septa: membranous, slightly thickened in 9/10 to 13/14. Gizzard: muscular and well developed in VI, but displaced to X, XI, with an average size (width × length) of 6.15 × 8.05 mm. Calciferous glands: eight pairs in VII-XIV, yellow bean-shaped with a brown round distal appendix in VII-XII, deprived of appendix and kidney-shaped in XIII-XIV; all with composite tubular structure. Esophagus-intestine transition in XIX; intestine without caeca. Typhlosole abruptly begining in XXV, structured as a large folded tissue ( Fig. 6E, F ). Hearts: six pairs, the two intestinal pairs well developed in X-XI, enclosed in the testes sacs. Excretory apparatus holoic, nephridia with simple nephrostome. Testes sacs: midventral or hypoesophagic in X and XI. Seminal vesicles: two pairs in XI-XII, short and flat lobulated, and respectively inserted ventrally in X and XI by a tube passing through the septa. Spermathecae: three pairs, VI, VII and VIII, without diverticula ( Fig. 6D ).

REMARKS

Of the Martiodrilus species found in French Guiana, M. (B.) flavus Decaëns & Bartz , n. sp. is easily distinguished by its relatively large size and yellow to grey skin pigmentation. The presence of three pairs of spermathecae links it to Botaria , however it differs from the other 22 species in the subgenus by their position in 5/6-7/8 instead of 6/7-8/9. It is similar in the position of the clitellum to Martiodrilus (Botaria) vassae Zicsi & Czusdi, 1999 and Martiodrilus (Botaria) gara Righi, 1995 , but differs in the position of the tubercula pubertatis in XIX-XXV instead of XXI-XXV in M. (B.) vassae or XIX-XXIII, ½XXIV in M. (B.) gara . It also differs from M. (B.) gara by its larger size (265 to 300 mm, instead of 50 to 100 mm), and from both species by its yellow to grey pigmentation, instead of green in M. (B.) vassae and reddish-violet in M. (B.) gara . Martiodrilus (B.) flavus Decaëns & Bartz , n. sp. is clearly separated from the other Martiodrilus species of the Mitaraka Massif by its COI barcode ( Table 2 ). This species corresponds to OTU#064 in Maggia et al. (2021).

Figures

FIG. 2. — (next page) The Mitaraka Massif: A, general view of the inselberg landscape from “Borne 1”, with “Sommet en Cloche” in the foreground, followed by “Tchoukouchipan” and “Mitaraka”;B, Astrocaryum forest plateau near Base Camp;C, transitional forest (TF1) on the slopes of the “Sommet en Cloche”;D, Rocky savannah (RS3) showing terrestrial bromeliad (Pepinia sp.) and transitional forest (TF2) in the background; E, a specimen of Martiodrilus (Botaria) tchoukouchipan Decaëns & Bartz n. sp. in the root mat of terrestrial bromeliads in a rocky savannah (RS2); F, the holotype of Martiodrilus (Botaria) flavus Decaëns & Bartz n. sp. in a transitional forest (TF2); G, detail of the terrestrial bromeliad beds in the rocky savannah RS3 (all photos by T. Decaëns).

FIG. 6. — Martiodrilus (Botaria) flavus Decaëns & Bartz n. sp.: A, external and lateral view of the anterior body (arrows indicate the clitellum position); B, external and semi-ventral view of the anterior body (arrows indicate the position of the tubercula pubertatis); C, dorsal dissection showing anterior internal anatomy; D, detail on the spermathecae;E, detail on the typhlosole when rolled up; F, detail on the typhlosole when unrolled;G, habitat preferences;H, microhabitat preferences.All images from the holotype specimen: CL, clitellum; DV, dorsal vessel;GZ, gizzard; IN, intestine;SP, spermathecae;SV, seminal vesicles;TF, typhlosole; TP, tubercula pubertatis; N, total number of specimens in the dataset. Scale bars: A-C, E, F, 10 mm; D, 5 mm.