Emitrombidium giocondi, Mąkol, Joanna & Sevsay, Sevgi, 2014

Mąkol, Joanna & Sevsay, Sevgi, 2014, The genus Emitrombidium Lombardini, 1949 (Actinotrichida: Trombidiidae) resurrected, Zootaxa 3786 (1), pp. 91-98 : 92-96

Emitrombidium giocondi sp. nov.

Diagnosis. Active postlarval forms (adults). Idiosoma oval in outline, widest at aspidosoma/opisthosoma border, rounded at termination. Dorsal opisthosomal setae of two types: longer pDS I and shorter pDS II, clear differences pertain to extreme forms. Stem of pDS I arcuately bent, stem of pDS II straight. Both pDS I and pDS II lanceolate (indistinctly flattened) in outline, narrowing apically, covered with husk-like setules distributed along stem. Longest setulae present in basal part of stem. Setal bases in form of truncated, sometimes irregular cones. Ventral setae not flattened, with three longitudinal rims (three-axial in cross section), each rim gradually passes into setules, latter much longer than in dorsal setae and evenly distributed along stem. Tarsus I elongated, almost parallel-sided. For other characters see diagnosis of genus.

Description. Active postlarval forms. Standard measurements given in Table 1 . Body oval in outline ( Fig. 1 ). Gnathosoma. Chelicera composed of base and cheliceral claw (digitus mobilis). Cheliceral blade (in side view) serrated across in proximal part, and along inner edge in distal part. Pedipalp typical of Trombidiidae , without modified, spine-like setae. About 3–5 smooth, whip-like setae placed on palp tibia, close to odontus base ( Fig. 2 ). Remaining setae on palps setulose. Odontus simple. Palp tarsus ( Fig 2 ) either equal to or slightly extending beyond termination of palp tibial claw. Several solenidia present at tip of segment.

Idiosoma, dorsum. Anterior margin of aspidosoma ( Fig. 3 ) concave. Crista metopica composed of anterior process, sensillary area and posterior process. Anterior process of crista short, formed of two linear, cuticular swellings, not clearly delimited in their anterior parts. Sensillary area ( Fig. 3 ) oval, located in anterior part of crista. Sensillary setae covered with tiny barbs, distributed predominantly along medial part of setae. Posterior process of crista slightly and gradually narrowing towards end, rounded at termination. Eyes pedunculate, situated at level of sensillary area of crista. Each eye composed of double lens; anterior lens larger than posterior one. Eye peduncles slightly narrowed at base and rounded apically, without distinct angle formed between one of peduncle’s sides and lens plane. Setae at anterior part of aspidosoma more slender, gradually pass into more robust setae towards opisthosoma termination.

Dorsal opisthosomal setae ( Figs 4 a, b, 6), differentiated into two types, both covered by husk-like setules and set on bases in shape of truncated, sometimes irregular, cones. Stem of longer setae (pDS I, Fig. 4 a) arcuated, gradually narrowing apically; stem termination covered by setules, which reach most apical part of seta, making an impression of apical part being dagger-like or coronate. Stem of shorter setae (pDS II, Fig. 4 b), straight, with similar termination as in pDS I. Both pDS I and pDS II with short setules, lined up in longitudinal rows extended along setal stem.

Idiosoma, venter. Ventral setae ( Fig. 7 ) more slender than those covering dorsal side of opisthosoma. Setules covering VS much longer than in DS, with basal parts lined up in distinct rims extended alongside setal stems (cross section of seta three-axial). Genital sclerites of female and male comparable in proportion ( Fig. 5 ) with two pairs of genital papillae. Epivalves similar in length to centrovalves; both covered by setae. Setae on epivalves with thicker stem than those on centrovalves and with more outstanding setules. Anus surrounded by valves, each valve covered with setae, more slender than VS.

Legs. Legs relatively short. Legs I longer than IV, legs II, III shorter. Normal setae covering trochanter – tarsus of all legs setulose. Specialized setae present on genua, tibiae and tarsi; setae relatively slender, curved (except for those placed along ventral part of tarsus I, the most distally placed seta on tibia III and IV and stout solenidion located distally on tarsus II). Tarsus I elongated, oval in female and trapezoidal, i.e. more distinctly widened at circa 1/3 of its length in male, in both sexes longer than tibia I. In one specimen - different length of tarsi I (446/ 284) on both sides of symmetry axis was observed due to anomaly (abnormally developed tarsus was not included in measurements). All tarsi terminated with paired claws. Dorsal side of claws with row of fimbriae. Pseudopulvillus absent.

Character Sample size, incl. holotype Mean Range Data for holotype ......continued on the next page Character Sample size, incl. holotype Mean Range Data for holotype Differential diagnosis. The new species differs from E. variepilosum in the shape of crista metopica (additional sclerite, placed posterior of the main rod of crista, absent in E. giocondi ) and in the shape of the dorsal opisthosomal setae (stem of pDS I slender and of pDS II thick in E. variepilosum , both of similar thickness in E. giocondi ).

Etymology. The specific epithet, referring to the first name of Giocondo Lombardini, is given in order to pay a tribute to the Author, whose work devoted to Emitrombidium was not acknowledged for more than half a century. Type material. Holotype (A2) and two paratypes (A4, A5) deposited at the Biozentrum Grindel und Zoologisches Museum (formerly: Zoologisches Institut und Museum der Universität Hamburg), Hamburg, Germany (ZIZMUH). Two paratypes (A3, DISE 069) in the senior author’s collection and two (A1, A6) – in the junior author’s collection. All specimens originate from the same locality (for details see Material and methods). Distribution. Turkey (Muğla Province).

Figures

FIGURE 1. Emitrombidium giocondi sp. nov., holotype, adult. Habitus. Not to scale.

FIGURES 2 – 5. Emitrombidium giocondi sp. nov., adult: 2. Palp, lateral aspect, setae on PaTr and PaFe omitted; 3. Crista metopica region; 4. Postero-dorsal setae of type I (a) and type II (b); 5. Genital opening, setae omitted.

FIGURES 6 – 7. Emitrombidium giocondi sp. nov., adult, SEM micrographs: 6. Postero-dorsal setae of type I (A) and type II (B). Arrows point to setal bases; 7. Postero-ventral setae at the level of genital opening.

Tables

TABLE 1. Metric data for Emitrombidium giocondi sp. nov. Active postlarval forms (adults).

PaTr (L)	7	67	49–78	64
PaFe (L)	7	247	224–270	245
PaGe (L)	7	61	54–64	59
PaTi (L)	7	99	91–108	98
Odo	7	82	78–88	78
PaTa (L)	7	112	101–122	108
ChCl	7	43	39–48	39
LB	7	2003	1830–2391	2025
WB	7	1375	1244–1586	1269
LB/WB	7	1.46	1.34–1.60	1.60
CML	7	216	205–221	205
S	7	213	205–223	210
SB	7	46	39–50	45
OP	7	97	88–108	100
pDS I max	7	125	118–135	118
pDS II min	7	47	38–55	50
pVS min	3	38	35–40	35
pVS max	3	108	100–120	100
GOP (L)	7	234	213–270	220
GOP (W)	7	183	168–210	175
GOP L/W	7	1.28	1.20–1.34	1.26
AOP (L)	7	101	75–125	125
AOP (W)	7	69	50–90	88
Cx I	7	225	189–250	250
Tr I	7	121	112–137	113
bFe I	7	217	186–245	216