Creefs heronum

Stępień, Anna & Błażewicz-Paszkowycz, Magdalena, 2013, Four new species and two new genera of Metapseudidae (Crustacea: Tanaidacea: Apseudomorpha) from Australian coral reefs, Zootaxa 3717 (4), pp. 559-592 : 577-584

Creefs heronum n. gen n. sp.

Figs 10–14

Material examined: Holotype, female (MTQ W 34242), HI 10-009E, 23°25'53.76"S, 152°2'57.48"E, Heron I., Sykes Reef W, coral rubble on sand, reef slope, depth 12 m, 13 November 2010, coll. C. Buxton. Allotype, male (MTQ W 34243), HI 10-009E, the same locality as holotype. Paratypes, 1 female (MTQ W 34244), HI 10-020B, 23°36'19.26"S, 152°1'26.04"E, Heron I., Lamont Reef, coarse sand, reef flat, depth 13 m, 16 November 2010, coll. C. Buxton; 1 female (MTQ W 34245), HI 10-055B, 23°26'59.35"S, 151°54'45.18"E, Heron I., Channel between Heron Island and Wistari Reef, coral rubble on sand, reef channel, depth 30 m, 26 November 2010, coll. C. Buxton. 25 females (MTQ W 34246) HI 10-009E, the same locatity as holotype; 23 females (MTQ W 34247) HI 10-009D the same lacality as holotype, but reef flat, depth 14 m.

Diagnosis. as for the genus, plus uropod endopod and exopod with four and three segments respectively

Description of female. Body ( Fig. 10 A, B) 2 mm long, 6.5 times as long as wide. Carapace 20% of total body length, without rostrum, eyes present, with pigment. Pereonite 1 0.4 times as long as wide, with short anterolateral seta; pereonites 2, 3 and 4 half as long as wide, each with short anterolateral seta, pereonite 5 half as long as wide, with two simple setae on each margin; pereonite 6 similar to pereonite 1. Pleon and pleotelson 16% of total body length, pleonite 1 free, 0.2 times as long as wide, with two setae on each margin, other pleonites fused with pleotelson; pleotelson with a pair of lateral setae and with protruding rounded tip.

Antennule ( Fig. 12 A) peduncle article 1 4.5 times as long as wide, both margins serrated with three penicillate setae and two simple setae on outer margin, and with three simple setae and one spine on inner margin; article 2 1.3 times as long as wide, 0.2 times as long as article 1, with three teeth and three simple setae distally on outer margin, and with two simple setae on inner margin; article 3 elongated, 3.4 times as long as wide, with one simple seta on outer margin, and two simple setae on inner margin; article 4 with one simple distal seta on inner margin; outer flagellum with three segments, segment 1 with two distal setae; segment 2 with one simple seta and one aesthetasc distally; segment 3 with four simple distal setae; inner flagellum two-segmented, segment 1 with two, segment 2 with three simple distal setae.

Antenna ( Fig. 12 C) with two peduncle articles, article 1 robust, 1.6 times as long as wide, with two proximal spines and two penicillate distal setae on outer margin, and with three spines proximally, and three simple setae on inner margin; article 2 as long as wide, with two simple setae.

Mouthparts. Epistome conspicuous ( Fig. 12 A). Right mandible ( Fig. 12 G) with finely serrated margin, setiferous lobe with one robust bifurcated seta and two pinnate setae; molar ( Fig. 12 H) serrated distally, with two simple subdistal setae; palp ( Fig. 12 F) with three articles, articles 1 and 2 4.4 times as long as wide, naked; article 3 0.4 times as long as article 2, with one short, one long pinnate distal setae. Left mandible ( Fig. 12 E) with finely serrated inner margin, lacinia mobilis with five teeth, setiferous lobe with two simple setae. Maxillule ( Fig. 12 J) outer endite with eight distal spines, inner endite with four simple setae; palp ( Fig. 12 K) two-articled, article 2 with two simple distal seta. Maxilla outer margin serrated ( Fig. 12 L) outer lobe of movable endite with four distal and two subdistal simple setae; inner lobe of movable endite with four simple setae; outer lobe of fixed endite with four simple and two trifurcated setae distally and with one plumose seta subdistally; inner lobe of fixed endite with six plumose and row of simple setae; inner margin with four spines. Epignath ( Fig. 12 D) narrow, with setose margins and with one terminal seta. Maxilliped palp ( Fig. 12 M) article 1 with one strong seta on outer margin; article 2 1.2 times as long as wide with serrated margin and with one distal spine, inner margin with row of nine simple setae; article 3 0.4 times as long as article 2, with row of six simple setae on inner margin; article 4 1.2 times as long as article 3, with 8 pinnate distal setae; endite ( Fig. 12 I) with four couling-hooks and with three pinnate setae on inner margin, with five setulose spines and three pinnate distal setae and with row of simple setae on outer margin.

Cheliped ( Fig. 13 A) basis 1.4 times as long as wide, with one simple distal seta on ventral margin; merus 2.3 times as long as wide, with one fine ventral seta; carpus five times as long as wide, with two simple setae along ventral margin and one dorsal seta; propodus 2.3 times as long as wide, with one simple seta on ventral margin, and two plumose setae near dactylus insertion; fixed finger half as long as propodus, with three simple setae on ventral margin, cutting edge with four simple setae, serrated.

Pereopod 1 ( Fig. 14 A): basis 3.8 times as long as wide, with two simple setae and two hook-like apophyses on dorsal margin, and with one simple seta on ventral margin distally; ischium 0.2 times as long as wide, with one simple seta on ventral margin; merus 1.6 times as long as wide, with one fine seta dorsally, with three simple setae and one small spine on ventral margin; carpus 1.6 times as long as wide, both margin serrated with three simple setae and one spine on dorsal margin, with two simple setae and three spines ventrally; propodus similar in length to carpus, half as wide as carpus, with one penicillate dorsal seta, ventral margin serrated with four spines, one simple, one pinnate setae, near dactylus insertion one simple setae and two spines; dactylus together with unguis half as long as propodus, with one dorsal and one ventral fine seta; unguis half as long as dactylus.

Pereopod 2 ( Fig. 14 B) basis three times as long as wide, with two processes proximally, one hook-like apophysis in the middle of length and two simple and one penicillate seta dorsally and with one simple ventral seta; ischium 0.3 times as long as wide, with one simple ventral seta; merus 1.7 times as long as wide, with one dorsal and two ventral simple setae; carpus 1.6 times as long as wide, both margin serrated, with one simple dorsal seta and with four spines, with two ventral simple setae, and with two spines and one simple seta distally; propodus 3.3 times as long as wide, half as wide as carpus, with one penicillate seta on dorsal margin, with four spines and denticles on ventral margin and with two spines, one pinnate and one plumose seta distally; dactylus together with unguis half as long as propodus, with one dorsal seta and two ventral simple setae; unguis half as long as dactylus.

Pereopod 3 ( Fig. 14 C) similar to pereopod 2, but basis 4.5 times as long as wide, with only one proximal spine and with two penicillate dorsal setae.

Pereopod 4 ( Fig. 14 D) basis five times as long as wide, with two penicillate ventral setae; ischium 0.4 times as long as wide; merus 1.5 times as long as wide, with one simple dorsal seta and two simple ventral setae; carpus 2.5 times as long as wide, with one simple dorsal seta, and with two spines and four simple setae distally; propodus ( Fig. 14 D’) 3.5 times as long as wide, similar in width to carpus, with eight pinnate setae and one simple seta distally, and four pinnate subdistal setae; dactylus together with unguis half as long as propodus, with one ventral and one dorsal simple seta; unguis 0.6 times as long as dactylus.

Pereopod 5 ( Fig. 14 E) basis four times as long as wide, with two penicillate setae and one simple setae dorsally, and with two simple ventral setae; ischium 0.3 times as long as wide, with one simple ventral seta; merus 2.6 times as long as wide, with one dorsal and ventral simple seta; carpus twice as long as wide, with one dorsal, two ventral simple setae and with one ventral spine; propodus 4.4 times as long as wide, similar in width to carpus, with one simple ventral and with three pinnate setae and three simple setae distally; dactylus together with unguis 0.7 times as long as propodus, with one ventral and one dorsal setae; unguis 0.3 times as long as dactylus.

Pereopod 6 ( Fig. 14 F) basis 3.3 times as long as wide, with one simple seta on ventral distal margin and penicillate dorsal seta; ischium 0.3 times as long as wide, with simple setae ventrally; merus twice as long as wide, with three simple distal seta; carpus 1.5 times as long as wide, with three long and one short distal setae; propodus 4 times as long as wide, 0.7 times as wide as carpus, with one penicillate seta on dorsal margin, with two simple setae along ventral margin and one fine setae distally; dactylus as in pereopod 5.

Uropods ( Fig. 13 D) basis 5.6 times as long as wide, with one simple distal seta and distodorsal hook-shape process; endopod with four segments, segment 2 with one simple and one penicillate setae distally; segment 3 with three, segment 4 with four simple setae distally; exopod with three segments, segment 3 with two simple distal setae.

Description of male. Body ( Fig. 11 A) 1.5 mm long. Generally similar to female, but differing in shape of antennule and cheliped.

Antennule ( Fig. 12 B) similar to that of female, but peduncle article 1 6.6 times as long as wide, without spines or denticles on inner margin; article 2 twice as long as wide; article 3 4.6 times as long as wide, with additional denticles on inner margin.

Cheliped ( Fig. 13 B) stronger than in female; basis 1.2 times as long as wide, with two simple setae on ventral margin, and with row of denticles on dorsal margin; merus twice as long as wide, with one simple ventral seta; carpus 1.8 times as long as wide, with five simple setae and denticles along ventral margin, and with one simple dorsodistal seta; propodus robust, as long as wide, with one simple seta on ventral margin and with two simple setae near dactylus insertion; fixed finger 0.6 times as long as propodus, with three setae ventrally and with four short and three long setae on cutting edge; dactylus 0.7 times as long as propodus, with two teeth and two short simple setae on inner margin.

Pereopod 1 ( Fig. 13 C) similar to female, but carpus more robust, 1.5 times as long as wide, with denticles and row of 18 setae along dorsal margin and with serrated ventral margin.

Distribution. Known only from the type locality (Heron Island, GBR) from coral rubble on sand.

Subfamily Msangiinae Gu t u, 2006

Figures

FIGURE 10. Creefs heronum n. gen. n. sp., holotype female. A body dorsal view; B body lateral view. Scale line = 1 mm.

FIGURE 11. Creefs heronum n. gen. n. sp., male. A body lateral view. Scale line = 1 mm.

FIGURE 12. Creefs heronum n. gen. n. sp. A antennule (female); B antennule (male); C antenna; D epignath; E left mandible; F palp of mandible; G right mandible; H molar process; I maxilliped endite J maxillule; K maxillule palp; L maxilla; M maxilliped. Scale line = 0.1 mm.

FIGURE 13. Creefs heronum n. gen. n. sp., A cheliped (female); B cheliped (male); C pereopod 1 (male); D uropod. Scale line = 0.1 mm.

FIGURE 14. Creefs heronum n. gen. n. sp., A pereopod 1; B pereopod 2; C pereopod 3; D pereopod 4; D’ propodus of pereopod 4; E pereopod 5; F pereopod 6. Scale line = 0. 1 mm.