Martiodrilus (Maipure) mitaraka 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 : 217-219

Martiodrilus (Maipure) mitaraka Decaëns & Bartz , n. sp.

( Fig. 13 )

urn:lsid:zoobank.org:act:DC414303-8A7E-4399-8E0B-F8048B5490FC

TYPE MATERIAL. — Holotype. French Guiana • Adult; Tumuc-Humac, Mitaraka Massif , slope forest on trail to Sommet en Cloche Inselberg , in the soil; 2°14’6”N, 54°27’11”W; 352 m a.s.l.; III.2015; T. Decaëns, E. Lapied leg.; BOLD Sample ID: EW-MI15-0360 ; MNHN.

Paratypes. French Guiana • 9 adult specimens; 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-MI15-0173 , EW-MI15-0178 , EW-MI15-0179 , EW-MI15-0196 , EW-MI15-0361 , EW-MI15-0365 , EW-MI15-0366 , EW-MI15-0367 , EW-MI15-0180 ; MNHN • 1 adult specimen; Tumuc-Humac, Mitaraka Massif , plateau forest on DIADEMA project C trail; 2°13’58”N, 54°26’38”W; 449 m a.s.l.; III.2015; T. Decaëns, E. Lapied leg.; BOLD Sample ID: EW-MI15-0297 ; CEFE • 1 adult specimen; Tumuc-Humac, Mitaraka Massif , slope forest on DIADEMA project C trail; 2°14’5”N, 54°26’42”W; 377 m a.s.l.; III.2015; T. Decaëns, E. Lapied leg.; BOLD Sample ID: EW-MI15-0369 ; CEFE • 2 adult specimens; Tumuc-Humac, Mitaraka Massif , transition forest # 1 Sommet en Cloche Inselberg ; 2°13’54”N, 54°27’39”W; 401 m a.s.l.; III.2015; T. Decaëns, E. Lapied leg.; BOLD Sample ID: EW-MI15-0335 , EW-MI15-0334 ; CEFE • 1 adult specimen; Tumuc-Humac, Mitaraka Massif , tropical rainforest on crowned mountain; unknown; unknown; III.2015; T. Decaëns, E. Lapied leg.; BOLD Sample ID: EW-MI15-0128 ; MNHN .

OTHER MATERIAL EXAMINED. — French Guiana • 1 cocoon; 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-MI15-0371 ; MNHN • 1 juvenile specimen; Tumuc-Humac, Mitaraka Massif , plateau forest on DIADEMA project C trail; 2°13’58”N, 54°26’38”W; 449 m a.s.l.; III.2015; T. Decaëns, E. Lapied leg.; BOLD Sample ID: EW-MI15-0293 ; MNHN • 3 juvenile specimens; Tumuc-Humac, Mitaraka Massif , slope forest on DIADEMA project A trail; 2°14’16”N, 54°27’7”W; 344 m a.s.l.; III.2015; T. Decaëns, E. Lapied leg.; BOLD Sample ID: EW-MI15-0210 , EW-MI15-0211 , EW-MI15-0212 ; MNHN • 3 juvenile specimens, 1 cocoon; Tumuc-Humac, Mitaraka Massif , transition forest # 1 Sommet en Cloche Inselberg ; 2°13’54”N, 54°27’39”W; 401 m a.s.l.; III.2015; T. Decaëns, E. Lapied leg.; BOLD Sample ID: EW- EW-MI15-0333 , EW-MI15-0341 , MI15-0350 , EW-MI15-0377 ; MNHN • 2 juvenile specimens; Tumuc-Humac, Mitaraka Massif , tropical rainforest on crowned mountain; NA/NA; NA m a.s.l.; III.2015; T. Decaëns, E. Lapied leg.; BOLD Sample ID: EW-MI15-0130 , EW-MI15-0131 ; MNHN .

ETYMOLOGY. — This species is named in reference to the Mitaraka Massif where the type material has been collected.

ECOLOGY. — Martiodrilus (M.) mitaraka Decaëns & Bartz , n. sp. has been found mostly in plateau forests (61.54% of specimens) and in inselberg transition forests (23.08%) ( Fig. 13E ). Most specimens were collected in the organo-mineral soil (61.54%) and to a lower extent in litter accumulation on granit rocks (19.23%) and in decaying trunks (19.23%) ( Fig. 13F ). Cocoons are tan yellow, spherical, 7-10 mm in diameter, with two mucrons at the anterior and posterior ends.

DISTRIBUTION. — Martiodrilus (M.) mitaraka Decaëns & Bartz , n. sp. is only known from the Mitaraka Massif.

DESCRIPTION

External morphology ( Fig. 13A, B, D )

Body shape cylindrical, slightly flattened after clitellum. Body pigmentation dorsally red-brown, ventrally light brown. Body length: 130 mm in the holotype, 100 to 140 mm in the paratypes (average: 116.7 mm; n = 3), after ethanol fixation. Body mass: 2.13 g after ethanol fixation in the holotype, 1.59 to 2.04 g in the paratypes (average: 1.74 g; n = 3). Diameter: 5 to 6.7 mm in the preclitellar region, 6.5 to 7.6 mm in the clitellum, 5.9 to 6 mm in the postclitellar region. Number of segments: 173 in the holotype, 107 to 167 in the paratypes (average: 137; n = 3). Prostomium proepilobic. One pair of longitudinal grooves going anterior to posterior through segment I in line of nephridial pores ( Fig. 13D ). Setae closely paired, ab beginning in II, cd in III or IV. Setal arrangement aa:ab:bc:cd:dd = 7:1:9:1:25. Clitellum in (dorsal ½ XIII, XIV) XV (XVI)-XXV, saddle-shaped to annular ( Fig. 13A ). Genital markings variable in V-VIII and in X, intraclitellar in XV and XXIII (ab position).Tubercula pubertatis linear in (XIX) XX-(XXV) XXVI ( Fig. 13B ). Male pores not recognised, and ovipores in XIV, pre-clitellar diagonally to b. Spermathecal pores in 4/5, 5/6, 6/7 and 7/8. Nephridial pores begining in II, in CD line.

Internal anatomy ( Fig. 13C )

Septa: membranous, slightly thickened in 6/7 to 16/17. Gizzard: muscular and well developed in VI, but displaced to X, XI, with an average size (width × length) of 4.50 × 4.90 mm. Calciferous glands: eight pairs in VII-XIV, the last three pairs two to three times the size of the others; all kidney-shaped with a lobular distal appendix and tubular composite structure. Esophagus-intestine transition in XVIII; intestine without caeca. Typhlosole abruptly begining in XXV/XXVII, structured as a long thin folded lamella occupying all the lumen. Hearts: six pairs, the two last intestinal pairs in X-XI well developed and enclosed in the testes sacs. Excretory apparatus holoic, nephridia with simple nephrostome.Testes sacs:periesophageal in X and XI. Seminal vesicles: two pairs in XI-XII; first pair enclosed in septa with hearts, calciferous glands and testes sacs in X, and forming a wing extending anteriously up to IX; the second pair going until XV/XVI. Spermathecae: four pairs, V, VI, VII, VIII; without diverticula.

REMARKS

M. (M.) mitaraka Decaëns & Bartz , n. sp. belongs to the subgenus Maipure due to the presence of four pairs of spermathecae. It is similar to the species of this subgenus whose clitellum is in XV-XXV: Martiodrilus (Maipure) ecuadoriensis (Benham, 1892) , Martiodrilus (Maipure) palmirus Zicsi & Feijoo,1994 , and M. (M.) ophioides . It also shares with the latter the position of the tubercula pubertatis in XX-XXVI. It differs from these three species, however, in the position of spermathecal pores in 4/5-7/8, instead of in this species 5/6-8/ 9 in the others. This species corresponds to OTU#081 in Maggia et al. (2021).

Figures

FIG. 13. — Martiodrilus (Maipure) mitaraka Decaëns & Bartz n. sp.: A, external and lateral view of the anterior body (arrows indicate the clitellum position); B, external and ventral view of the anterior body (arrows indicate the position of the tubercula pubertatis); C, dorsal dissection showing anterior internal anatomy; D, detail of anterior segments (external lateral view); E, habitat preferences; F, microhabitat preferences. All images from the holotype; CL, clitellum; GZ, gizzard; SP, spermathecae; SV, seminal vesicles; TF, tiphlosole; TP, tubercula pubertatis;N, total number of specimens in the dataset. Scale bars:A-C,5 mm;D, 2.5 mm.