Anoplodactylus mirim, Lucena, Rudá Amorim, Araújo, Joafrâncio Pereira De & Christoffersen, Martin Lindsey, 2015

Lucena, Rudá Amorim, Araújo, Joafrâncio Pereira De & Christoffersen, Martin Lindsey, 2015, A new species of Anoplodactylus (Pycnogonida: Phoxichilidiidae) from Brazil, with a case of gynandromorphism in Anoplodactylus eroticus Stock, 1968, Zootaxa 4000 (4), pp. 428-444 : 432-435

Anoplodactylus mirim sp. nov.

( Figs 6–11 )

Material types: Holotype—( UFPB.PYC–085) 1♂, Barra de Mamanguape–PB, 11 Aug 2010, coll. PBP. Paratypes—( UFPB.PYC–165) 1♂, 1♀, Barra de Mamanguape–PB, 11 Aug 2010, coll. PBP.

Further material—Paraíba: ( UFPB.PYC–006) 1♂, Coqueirinho, 28 Aug 2011, coll. PBP; ( UFPB.PYC–066) 1♀, Barra de Camaratuba, 12 Aug 2010, coll. PBP; ( UFPB.PYC–067) 1♂, 1♀, 07°03’48”S 34°45’10”W, 21 Mar 2006, coll. P. Riul, 15m; ( UFPB.PYC–068) 1♀, 7º 18’ 68”S 34º 33’W, 14 May 1981, coll. Projeto Algas–PB, 30m; ( UFPB.PYC–124) 1♀, Tabatinga, 17 Sep 2012, col. PBP.

Diagnosis: Trunk without dorsal segmentation. Lateral processes with a rounded tubercle dorsally, and with an apical seta on processes 1 to 3. Cheliphores with a small tubercle ventrally. Fingers toothed, with one on the movable and two on the immovable fingers. Cement gland duct erect, short and cup-shaped, located on anterior half of femur, and forming a 90º angle in its distal margin. Propodus heel with two large spines and another two smaller ones, in the inner margin, turned towards the sole; sole with 13 small spines starting at half length of sole. Auxiliaries very small.

Description of male (holotype): Trunk very short, without dorsal segmentation. Proboscis short and robust; distal region turned upward; with short setae ventrally and laterally (fig 8). Lateral processes separated by about half of their diameter; with a rounded tubercle dorsally; on lateral process 1 to 3 the tubercle has an apical seta. Ocular tubercle cylindrical, with a couple of setae on each side; distal margin tricuspidate; pale eyes. Abdomen higher than ocular tubercle, subapically surrounded by some setae (figs 6 and 7).

Cheliphore slender. Scape single-jointed; with a small tubercle ventrally, near the proximal margin, and an elongated dorsal seta near the distal margin. Chelae with a short and an elongated seta on dorsal surface. Fingers toothed; moveable finger having one dorso-lateral seta and one tooth, and immovable finger having two teeth in the internal margin (fig 9). Oviger 6-articled, with sparse setae, starting on 2nd article, and having a maximum number of setae in the 5th article (fig 10). 1st article almost as large as long. 3rd article longest, with a constriction near the proximal region. 6th article very short, sub-cylindrical.

Legs short and robust (fig 11). Coxa 1 smaller than coxa 3. Coxa 2 of the same length as coxae 1 and 3 together; small dorso-median rounded tubercle, few ventral setae; ventral spur short in all legs. Coxae 3 with ventral setae. Femur is the longest and most robust article; with an elongated terminal seta. Cement gland duct erect, short and cup-shaped, located before half of femur, and forming a 90º angle in its distal margin (detail of fig 11). Tibia 1 and 2 with an elongated seta terminally. Tarsus with ventral setae, and a dorso-distal projection. Propodus with heel forming a 90º angle with sole; heel with two large spines and another two smaller ones, in the inner margin, turned to the sole; sole with four narrow setae, and 13 small spines starting at half length of sole, forming an analog on to a cutting lamella (detail of fig 11). Main claw more than 2/3 of propodus length. Auxiliaries very small.

Genital pore opening on second coxae of legs 3 and 4.

Female: The female is very similar to the male, differing only in a larger opening of genital pores present in all legs, and in the proboscis, which has more setae than male. The tubercles on the lateral processes are smaller than those in males.

Measurements (Holotype —mm): length of trunk, 0.38; width of trunk (measured on first lateral process), 0.29; length of abdomen, 0.12; length of proboscis, 0.20; length of scape of cheliphore, 0.15; length of chela, 0.08; length of article of 3rd leg—coxa 1, 0.07; coxa 2, 0.13; coxa 3, 0.09; femur, 0.22; tibia 1, 0.19; tibia 2, 0.18; tarsus, 0.04; propodus, 0.16; main claw, 0.11; auxiliary claw, 0.0 1.

Trunk Segmentation Lateral process Proboscis Setae on Teeth on Rudimentary Ovigers Auxiliaries proboscis immovable palp article 2 and claws finger 3

. brasiliensis Present , between 1–2 and 2–3 Separated by ½ of their own diameter, Short Absent Absent Absent 2 = half of 3 Minuscule without ornamentation or absent

. brochus Absent Separated by their own diameter, with Short Absent Absent Present 2 little Present

a dorsal tubercle and an apical seta shorter than 3

. chamorrus Absent Contiguous , with a small dorsal Short Absent Absent Present 2 little Absent

tubercle shorter than 3

. marcusi Absent Contiguous Elongated Absent Absent Absent 2 = 3 Very short

. micros Presente , between 1–2 and 2–3 Separated by less than their own Short Absent Absent Absent 2 little Present

diameter, with a small dorsal tubercle shorter than with apical seta 3

. minusculus Absent Contiguous , with a small tubercle and Short Absent Variable Absent 2 = 3, very Absent

an apical seta short Depth: 0– 30m.

Distribution: Brazil (Paraíba).

Etymology: The species name mirim is derived from Tupi-Guarani language, meaning small, in reference to its small size.

Comments: Commonly representatives of Anoplodactylus are of median size, varying from 0.6 to 6mm ( Arango & Maxmen, 2006). However, it is noteworthy that some species have a very small body size, having been included in the A. pygmaeus complex by Stock (1974). In this group Stock (1974) included A. pygmaeus (Hodge, 1864) , A. brasiliensis Hedgpeth, 1948 , A. trispinosus Stock, 1951 , A. minutissimus Stock, 1954 , A. micros Bourdillon, 1955 , A. minusculus Clark, 1970 , A. spinirotrum Stock, 1973 , and A. turbidus Stock, 1974 . We may also consider A. marcusi (Mello-Leitão, 1949) , A. chamorrus Child, 1983 , A. vulcanus Child, 1992 , A. brochus Child, 1996 and A. nanus as having a reduced body (<0.6mm). Anoplodactylus mirim sp. n. is included in this complex, being distinguished from the other species by the characters presented in Table 1.

A. micros is morphologically closest to A. mirim for having the lateral processes separated by less than half of their own diameter, for having a rounded tubercule bearing an apical seta, and also by the presence of auxiliary claws. A. mirim differs from this species by: 1) the absence of segmentation (present in segments 1-2 and 2-3 in A. micros ); 2) by the sole formed by 13 small spines (cutting lamina in A. micros ); 3) cement gland small and more erect, forming an angle of 90º with the femur in distal region (tube of cement gland larger and forming an acute angle with the femur in A. micros ); 4) chelae with one tooth on movable finger and two teeth on immovable finger (three teeth on movable finger and two on immovable finger in A. micros ); 5) presence of two robust spines on anterior surface of heel (only one in A. micros ); and 6) legs short and robust in relation to body (elongate in A. micros ).

A mirim differs from A. chamorrus , A. marcusi , A. minusculus , and A. vulcanus , mainly because those species have contiguous lateral processes and the lateral processes are separated in A. mirim . A. brasiliensis , A. pygmaeus and A. spinirostrum lacks auxiliary claws, while auxiliary claws are present in A. mirim .

The new species differs from A. brochus , A.nanus and A. turbidus , which do not have ventral setae on the proboscis (present in A. mirim ). It differs from A. minutissimus and A. trispinosus , which have no teeth on the movable finger of chelae (present in A. mirim ). Finally, the latter three mentioned species have a rudimentary palp (completely absent in A. mirim ).

Figures

FIGURES 6 – 11. Anoplodactylus mirim (UFPB. PYC – 085). Male. Habitus: 6, dorsal; 7, lateral; 8, ventral proboscis; 9, chela; 10, oviger; 11, 3 rd leg. Scale bar: Figs. 6 – 8, 0.05 mm; Fig. 9, 0.025 mm; Figs. 10 – 11, 0.05 mm, details of Fig. 11, 0.025 mm.