Ityphilus donatellae, Pereira, 2012

Pereira, Luis Alberto, 2012, A New Dwarf Species, New Distribution Records, And Supplementary Descriptive Notes Of The Centipede Genus Ityphilus Cook, 1899 (Chilopoda: Geophilomorpha: Ballophilidae) From Central Amazonia, Brazil, Papéis Avulsos de Zoologia 52 (25), pp. 291-309 : 292-298

Ityphilus donatellae sp. nov.

( Figs. 1-14 )

Ityphilus calinus : Pereira, Foddai & Minelli, 2000:1, 6-8 (non Ityphilus calinus Chamberlin, 1957 ).

Diagnosis: An Ityphilus species with internal edge of forcipular tarsungulum partially serrate, very small body size (8.5 to 11 mm), and low number of leg-bearing segments (41 or 43). Among the other Neotropical members of the genus, it only shares the last trait with Ityphilus calinus Chamberlin, 1957 . Ityphilus donatellae sp. nov. can be principally differentiated from I. calinus on the basis of the following selected traits (those for the latter are given in parentheses): antennae curved at middle, truly geniculate, Figs. 1 , 9, 10 , 12 (“curved at middle but not truly geniculate”, Fig. 26 ); antennae distally strongly clavate, Figs. 1 , 9, 10 , 12 (antennae distally slightly thickened, Fig. 26 ); a.a. XIV wider than long, in the proportion ca. 0.93: 1, Figs. 1 , 9, 10 , 12 (a.a. XIV longer than wide in the proportion ca. 1.49: 1, Fig. 26 ). Other traits differentiating both species, as in Table 1.

Remarks: The differential characters listed in the previous lines and Table 1 (especially those related to the antennae) are stable enough in ballophilids, thus giving confidence in considering the specimens assigned to Ityphilus calinus in Pereira et al. (2000), as belonging to a species different to it, and new for the genus.

Among the Neotropical species of Ityphilus , I. crabilli Pereira, Minelli & Barbieri, 1994 and I. guianensis Chamberlin, 1921 (both with forcipular tarsungulum serrate) share with I. donatellae a roughly similar range of leg-bearing segments. I. calinus Chamberin, 1957 and I. savannus Chamberlin, 1943 (of which it is unknown whether the forcipular tarsungulum is serrate or smooth) also share a similar range. Ityphilus donatellae can be separated from I. calinus as shown in Table 1. It can be confidently differentiated from the other three taxa, by means of the following selected traits (the corresponding features for the new species are given in parentheses):

— I. crabilli : male with 47, female with 47, 49, 51, 53 leg-bearing segments; body length 15 mm for males, 21 mm for females; antennae apically moderately clavate; specialized sensilla on apex of a.a. XIV with two very small apical branches; coxosternite of first maxillae with lappets; chitin-lines of forcipular coxosternite incomplete. (Male with 41, female with 43 leg-bearing segments; body length 8.5 mm in the male, 11 mm in females; antennae apically strongly clavate, Figs. 1 , 9, 10 , 12 ; specialized sensilla on apex of a.a. XIV not split apically; coxosternite of first maxillae without lappets, Fig. 3 ; chitin-lines of forcipular coxosternite complete, Fig. 4 : a).

— I. guianensis : clypeus with ca. six setae; sternite of leg-bearing segment 1 with pore-field; 49, 55 leg-bearing segments; body length 23 mm; chitin-lines of forcipular coxosternite incomplete. (Clypeus with ca. 12 setae; sternite of leg-bearing segment 1 without pore-field; (other features, already mentioned above)).

— I. savannus : pore-fields present from sternite of leg-bearing segment 2 to fourth sternite from rear end of the body; 55 leg-bearing segments; body length 16 mm. (Ventral pore-fields present from second to penultimate leg-bearing segment; (other features, already mentioned above)).

Ityphilus donatellae sp. nov. can be separated from the other Neotropical species of Ityphilus characterized by having the forcipular tarsungulum serrate, by using the key below.

Type material (hereby designated): BRAZIL: Amazonas : secondary upland forest (02°34’S, 60°06’W), M.O. de A. Ribeiro leg., 7 November 1990: holotype female, 43 leg-bearing segments, body length 11 mm ( INPA) ; same locality and collector, 6 December 1990: paratype male, 41 leg-bearing segments, body length 8.5 mm ( INPA) ; same locality and collector, 9 October 1990: paratype female, 43 leg-bearing segments, body length 11 mm ( MLP) .

Remarks: For details of morphological characters of I. donatellae sp. nov., see the “Redescription” of “ Ityphilus calinus Chamberlin, 1957 ” given in Pereira et al. (2000:6-8, figs. 42-68), in which the present holotype female (cited as Specimen “A”) and paratype male (cited as Specimen “B”) are described and illustrated in detail. Nevertheless, the following complementary morphological data can be added here based on the original figures of those specimens. Supplementary precisions on external morphology (together with new illustrations) are incorporated from the paratype female (examined here).

Additional morphological information:

Holotype female: Antennae nearly contiguous at base ( Fig. 2 ), curved at middle and truly geniculate, apically distinctly thickened, strongly clavate ( Fig. 1 ). Ratio of width of a.a. XI (= widest antennomere of distal antennal half)/width of a.a. VI (= narrowest antennomere of basal antennal half), ca. 1.58: 1; ratio of length of a.a. XIV/length of a.a. XI to XIII taken together, ca. 1.25: 1; ratio length of a.a. XIV/length of a.a. XIII, ca. 4.0: 1. Length/width ratio of left a.a. I to XIV as follows: I (0.50: 1); II (0.60: 1); III (0.60: 1); IV (0.60: 1); V (0.66: 1); VI (0.48: 1); VII (0.44: 1); VIII (0.36: 1); IX (0.33: 1); X (0.27: 1); XI (0.25: 1); XII (0.22: 1); XIII (0.24: 1); XIV (0.93: 1).

Forcipular segment ( Fig. 4 ): forcipular coxosternite with maximum width/length at the middle ratio, ca. 1.70: 1; forcipular telopodite with ratio of maximum length/maximum width of trochanteroprefemur, ca. 1.06: 1.

Ultimate leg-bearing segment ( Figs. 5, 6 ): wider than the penultimate leg-bearing segment in the proportion, ca. 1.16: 1; length/width ratio of tergite 0.68: 1; length/width ratio of sternite, 0.85: 1. Ultimate legs: ratio length of telopodites/length of sternite ca. 2.02: 1; ratio width of trochanter/width of tarsus 2, ca. 3.4: 1.

Paratype male: Ultimate leg-bearing segment ( Figs. 7, 8 ): wider than the penultimate leg-bearing segment in the proportion, ca. 1.35: 1; length/width ratio of tergite 0.88: 1; length/width ratio of sternite, 0.81: 1. Ultimate legs: ratio length of telopodites/ length of sternite, ca. 2.43: 1; ratio width of trochanter/width of tarsus 2, ca. 3.0: 1.

Paratype female: Antennae: dorsal chaetotaxy of a.a. I-VIII represented by setae of different lengths, few in number and similar to those on the ventral side, setae on a.a. IX-XIV larger and much less numerous than those on ventral side ( Fig. 9 ). Contour of appendages as in Figs. 10 , 12 .

Cephalic plate: surface with reticulation as in Fig. 13 ; ratio of maximum width of cephalic plate/ maximum width of forcipular tergite, ca. 1.05: 1.

Forcipular segment: forcipular tergite a little wider than the tergite of the first leg-bearing segment (in the proportion ca. 1.04: 1). Tarsungula when closed wholly behind the anterior margin of the head ( Fig. 14 ).

Tergites of leg-bearing segments: sulci not evident (apparently absent). Spermathecae (full of spermatozoa) located at level of the leg-bearing segments 38, 39, shape of posterior spermatheca as in Fig. 11 : a.

Etymology: This species is dedicated to Dr. Donatella Foddai (Padova, Italy), who was a kind partner in previous studies on geophilomorph centipedes.

Type locality: BRAZIL: Amazonas : secondary upland forest (02°34’S, 60°06’W) .

Known range: BRAZIL: Amazonas : secondary upland forest (02°34’S, 60°06’W); Adolpho Ducke Forest Reserve (02°55’S, 59°59’W) .

Figures

FIGURES 1‑8: (1-6): Ityphilus donatellae sp. nov., (female holotype; Brazil: Amazonas: 02°34’S, 60°06’W): (1) Left antenna, ventral; (2) Clypeus and bases of antennae; (3) Left side of first maxillae, dorsal; (4) Forcipular segment, ventral (a: chitin-lines); (5) Ultimate leg-bearing segment and postpedal segments, dorsal; (6) Ultimate leg-bearing segment and postpedal segments, ventral. (From Pereira et al., 2000). (7-8): Ityphilus donatellae sp. nov., (male paratype; Brazil: Amazonas: 02°34’S, 60°06’W): (7) Ultimate leg-bearing segment and postpedal segments, dorsal; (8) Ultimate leg-bearing segment and postpedal segments, ventral. (From Pereira et al., 2000). Scale bars: 0.03 mm (3); 0.1 mm (1, 2, 5-8); 0.2 mm (4).

FIGURES 9‑11: Ityphilus donatellae sp. nov., (female paratype; Brazil: Amazonas: 02°34’S, 60°06’W): (9) Left antenna, dorsal; (10) Contour of antennae, ventral; (11) posterior spermatheca at level of leg-bearing segment 39, ventral (a: spermatheca). Scale bar: 0.1 mm (9-11).

FIGURES 12‑14: Ityphilus donatellae sp. nov., (female paratype; Brazil: Amazonas: 02°34’S, 60°06’W): (12) Contour of antennae and cephalic plate; (13) Chaetotaxy and detail of areolation of cephalic plate; (14) Forcipular segment, cephalic capsule and bases of antennae, ventral (mouthparts and setae, suppressed). Scale bars: 0.1 mm (12, 13); 0.2 mm (14).

FIGURES 24‑29: (24-25): Ityphilus demoraisi Pereira, Minelli & Barbieri, 1995, (female holotype; Brazil: Amazonas: Adolpho Ducke Forest Reserve): (24) Ultimate leg-bearing segment and postpedal segments, ventral; (25) Right coxal organs, ventral (From Pereira et al., 1995). (26): Ityphilus calinus Chamberlin, 1957 (male holotype; “Colombia: 13 mi. W. of Cali, Valle”): Anterior end of the body, dorsal. (From Chamberlin, 1957). (27): Ityphilus ceibanus Chamberlin, 1922, (type (sex?); Honduras: La Ceiba): Anterior end of body, dorsal. (From Chamberlin, 1922). (28-29): Ityphilus sensibilis Pereira, Foddai & Minelli, 2000, (female holotype; Brazil: Amazonas: 02°34’S, 60°06’W): (28) Clypeus and bases of antennae (a: strong stout seta); (29) Detail of duct and calyx of poison gland in left forcipular telopodite, ventral (a: internal edge of tarsungulum, entirely serrate). (From Pereira et al. 2000). Scale bars: 0.1 mm (28, 29); 0.2 mm (25); 0.3 mm (24); no scales available (26, 27).