Pancoloides moverleyi, Edgar, 2008

Edgar, Graham J., 2008, Shallow water Tanaidae (Crustacea: Tanaidacea) of Australia, Zootaxa 1836 (1), pp. 1-92 : 85-90

publication ID	https://doi.org/ 10.11646/zootaxa.1836.1.1
persistent identifier	https://treatment.plazi.org/id/676CB04D-FFC6-FFA0-FF32-FC65F84A36F7
treatment provided by	Felipe
scientific name	Pancoloides moverleyi
status	sp. nov.

Treatment

Pancoloides moverleyi View in CoL n. sp.

( Figs 43–45 View FIGURE 43 View FIGURE 44 View FIGURE 45 )

Material examined. Holotype. Male ( NMV J56155 View Materials ), 2.3 mm, Port Hobart , Tas, pylon scrapings collected by Aquenal Pty Ltd during introduced pest surveys, 21 Feb 2002.

Paratypes. Three males ( NMV J56156 View Materials ), holotype location .

Diagnosis. With characters of genus. Dorsal surface with fine dark spots coalescing as patches of pigment, particularly behind eye and on postero-lateral lobes of cephalothorax; antennule article 1 about five times longer than wide in male, terminal article with five aesthetascs in male; left mandible with large toothlike lacinia mobilis with digitate outer margin, right mandible with lacinia mobilis present as peg-like structure; cheliped greatly expanded in male, with dactylus narrow, elongate and curved; pereopod 1 coxa produced anteriorly into slight bulge with one seta; pleopods 1 and 2 similar, basal article with five setae on outer margin; pleopod 3 with only three setae on outer margin; uropod with six or seven articles in mature individuals.

Description. FEMALE unknown

MALE. Body ( Fig. 43 View FIGURE 43 ). Length to 2.4 mm; preserved specimens with fine spots coalescing as patches of pigment, particularly behind eye and on postero-lateral lobes of cephalothorax and towards the posterior on the dorsal surface of pereonites 4–6.

Cephalothorax pear-shaped in dorsal view, length slightly greater than width, about one-quarter body length.

Pereon occupies about 53% of total length; pereonites with several setae along anterio-dorsal and lateral margins; pereonite 1 length about one-fifth width; pereonites 2 and 3 similar, almost twice length of pereonite 1; pereonites 4 and 5 similar, about 1.5 times length of pereonite 3; pereonite 6 about three-quarters length of pereonite 5.

Pleonites together one-sixth as long as body; pleonites 1, 2 and 3 decreasing in length and width, each about four-fifths length of preceding segment; pleonites 4 and 5 similar, together as long as pleonite 3.

Pleotelson about length of pleonite 1; posterior margin with pair of short setae central between pair of long setae, three setae anterior to articulation with uropod, three setae ventro-laterally.

Antennule ( Fig. 43 View FIGURE 43 ). Total length about 1.3 times length of cephalothorax, with article 1 about five times longer than wide, with three pappose setae one-fifth distance and simple seta one-third distance along outer margin, and several pappose and long simple setae distally; article 2 about one-third length of article 1, about 1.7 times longer than wide, with about seven setae distally; article 3 length about three time width; article 4 greatly reduced and cap-shaped, with numerous long setae and five aesthetascs.

Antenna ( Fig. 43 View FIGURE 43 ). Six articles; article 2 length three times width, with two distal setae; article 3 half length of article 2, lacking setae; article 4 length 2.5 times that of article 3, with three long distal setae; article 5 two-third length of article 4, with five or six simple and pappose setae distally; article 6 length 1.5 times width, with numerous long setae.

Mouthparts ( Fig. 44 View FIGURE 44 ). Labrum with setulose fringe.

Left mandible with large tooth-like lacinia mobilis with digitate outer margin, large denticulate seta at base, pars incisiva with indented outer margin, pars molaris broad and corrugated; right mandible with lacinia mobilis present as peg-like structure, denticulate seta at base, pars incisiva smooth and acute, pars molaris broad and corrugated..

Labium with inner lobe setulose; outer lobe setulose on distal margin, with pointed terminal process and with very fine spines projecting from proximal lateral margins.

Maxillule endite with eight large terminal spiniform setae, setulose on outer margin near base of spines; palp with five long setae.

Maxilliped coxa and basis not joined medially; coxa with two proximo-medial setae; basis with fine marginal setules, with a short distal seta; endite setulose around margin, with two small spiniform setae distal near medial margin, two small spiniform setae medial on distal margin and two circumplumose setae near distal margin that are about one third length of long setae on inner margin of palp; palp with four articles, article 1 as long as wide with simple seta distal on outer margin and fine marginal setules, article 2 slightly longer than article 1 with single seta distal on outer margin, four or five very long setae extending distally in a row from midway along inner margin and two long distal plumose setae, article 3 two-thirds length of article 2, fringed with about nine long setae along inner margin, article 4 similar in length to article 3 but two-thirds width, with a long seta distal on outer margin, a long terminal seta, and two adjacent rows of about five setae distal on inner margin.

Epignath with terminal circumplumose seta and fringe of fine setules.

Cheliped ( Fig. 43 View FIGURE 43 ). Basis longer than wide with one distal seta near ventral margin and one seta adjacent to dorsal articulation with merus; merus triangular with three setae two-thirds distance along ventral margin; carpus similar in length to basis, slightly wider than long, with three setae distal near ventral margin and group of about three setae distal on dorsal margin; propodus nearly twice length of carpus, width nearly twice length, fixed finger elongate and gradually declining in width, with large terminal spiniform seta, about five setae midway along ventral margin, about eight setae near terminal seta along dorsal margin of fixed finger and group of four setae plus a lateral seta near articulation with dactylus; dactylus smooth, curved, elongate and narrow, lacking row of small setae along ventral margin, unguis short and solid, about one eighth total length of dactylus.

Pereopod 1 ( Fig. 45 View FIGURE 45 ). Coxa produced anteriorly into slight bulge with one seta; basis length approximately five times width; merus about one-quarter length of basis; carpus 1.5 times length of merus; propodus length similar to merus and carpus together, with thee distal setae near; unguis two-fifths length of dactylus.

Pereopods 2 and 3 ( Fig. 45 View FIGURE 45 ). Similar; basis width one-quarter length, length slightly less than merus, carpus and propodus together; merus two-fifths length of basis, with short spiniform seta and two simple setae distal on ventral margin and one plumose seta distal on dorsal margin; carpus two-thirds length of merus, with about six serrated spiniform setae near distal margin and small spiniform setae evenly-spaced along ventral margin; propodus 1.5 times length of carpus, with about three simple setae and seven very small spiniform setae evenly-distributed along ventral margin; unguis half length of dactylus.

Pereopods 4 and 5 ( Fig. 45 View FIGURE 45 ). Similar; basis width about one-third length; merus with a pair of large spiniform setae and simple seta distal on ventral margin; carpus with two adjacent rows of two and three serrated spiniform setae near distal margin; propodus slightly longer than merus, with about seven very small spini- form setae evenly-distributed along ventral margin, two simple setae distal near ventral margin and pappose seta plus paired long simple seta distal near dorsal margin; unguis merged into claw-like dactylus, with comblike lateral rows of about seven flattened setae.

Pereopod 6 ( Fig. 45 View FIGURE 45 ). Basis width about one-third length; merus with a pair of large spiniform setae and simple seta distal on ventral margin and two simple setae distal near dorsal margin; carpus with four spiniform setae and two long plumose setae on distal margin; propodus with distal comb-like row of about seven flattened denticulate setae and dorso-distal group of paired long simple setae and pappose seta; dactylus with lateral comb-like rows of about eight setae.

Pleopods 1–2 ( Fig. 45 View FIGURE 45 ). Similar, with five plumose setae along outer margin and one plumose seta on inner margin, exopod with about 28 plumose setae along outer margin, endopod with one plumose seta on inner margin, large terminal circumplumose seta and about 14 plumose setae along outer margin.

Pleopod 3 ( Fig. 45 View FIGURE 45 ). Basal article with three plumose setae along outer margin and one plumose seta on inner margin, exopod with about 24 plumose setae along outer margin, endopod with one plumose seta on inner margin, large terminal circumplumose seta and about ten plumose setae along outer margin.

Uropod ( Fig. 45 View FIGURE 45 ). Five articles; basal article length about twice width, with about five distal setae; article 2 two-thirds length of basal article, lacking setae; 3, 4 and 5 similar in length, each about two-third width of preceding article, each with about five simple seta and plumose seta.

Etymology. Named in recognition of contributions to crustacean taxonomy and ecology in Tasmania and Victoria by John Moverley, including macrobenthic surveys of the Hobart region.

Distribution. Port Hobart, Tasmania. 0–3 m depth.

Remarks. Only males of this species are presently known. By analogy to related species, females are likely to be similar morphologically to males other than in more normal shape of cephalothorax, cheliped, antennule, antenna and pleopod 3.

In the distinctive shape of the cheliped, antennules and antennae, and reduction in setation of pleopod 3, the species shows affinity to male individuals in the genera Pancoloides , Hexapleomera , Pancolus and Monoditotanais (see Sieg, 1980b). Pancoloides moverleyi nevertheless differs from species of Monoditotanais and Pancolus in possessing five rather than four or three pleonites plus pleotelson, and from species of Zeuxo and Zeuxoides in the strong sexual dimorphism of males and reduction in pleopod 3.

This species could reasonably be assigned to either Pancoloides or Hexapleomera . In terms of shape of cheliped, antenna, antennule and mandibles, normal final uropod article, and relatively minor reduction in setation of pleopod 3, it shows greatest similarity with Hexapleomera ; however, in the shape and proportions of pereonites, pleonites and pereopods, including number of spiniform setae on pereopods 2 and 3, and number of setae on the basal pleopod article, the species appears more closely allied with Pancoloides . This species is here assigned to Pancoloides on the arguably trivial grounds that it is free-living and clearly sits outside the Hexapleomera complex as currently recognised, which is adapted for a pelagic life attached to sea turtles.

Pancoloides moverleyi shares most morphological features of Pancoloides litoralis (Vanhöffen) , the only known species in the genus Pancoloides ( Sieg, 1980b) . It does, however, differ from that subantarctic species in possessing a normal rather than reduced terminal uropod article (thereby also differing from species of Pancolus and Zeuxoides ), a uropod with five rather than four segments, relatively minor reduction in setation of pleopod 3, more elongate second article of antenna, and male cheliped fixed finger that is less elongate.

Pancoloides moverleyi may represent an introduction to south-eastern Tasmania that has not been reported so far from its native range. The species has not been recorded from undisturbed habitats in Australia, only from pylon scrapings in the Port of Hobart, where a number of other species that are likely-introduced were also recorded (e.g. the amphipods Corophium acherusicum , Corophium insidiosum, Caprella acanthogaster and Jassa marmorata) ( Aquenal 2002).