Gnathia marleyi Farquharson, Smit & Sikkel, 2012, sp. nov.
Creators: name: Farquharson, Charon
name: Smit, Nico J.
name: Sikkel, Paul C.
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Isopoda
Gnathiidae
Gnathia
Gnathia marleyi

description: Gnathia marleyi sp. nov.
Figs 1–9
Material examined. Holotype. Male, 3.3 mm, 18 June 2008 off Lameshur Bay, St. John, US Virgin Islands (18°18’59.32”N, 64°43’24.5”W), American Museum of Natural History (Crustacea Cat. No. 20223). Paratypes. 10 males, 6 females, 10 third stage pranizae off Lameshur Bay, St. John, US Virgin Islands (18°18’59.32”N, 64°43’24.5”W), American Museum of Natural History (Crustacea Cat. No. 20223). Additional material. 4 males, December 2008, Saltpond Bay, St. John, USVI (18°18’35.28”N, 64°43’02.45”W), American Museum of Natural History (Crustacea Cat. No. 20223); 7 males, January 2009, Punto Soldado, Culebra, Puerto Rico (18°16’41.78’’N, 65°17’08.83”W), American Museum of Natural History (Crustacea Cat. No. 20223); 3 males, June 2009, Lee Stocking Island, Bahamas (CMRC Marine Science Laboratory boat dock) (23°77’02.66”N, 76°10’07.26”W), American Museum of Natural History (Crustacea Cat. No. 20223); 11 males, 4 third stage pranizae, August 2009, White Bay, Guana Island, British Virgin Islands (18°28”28.31”N, 64°34’30.83”W), American Museum of Natural History (Crustacea Cat. No. 20223); 4 males, October 2009, Fort Bay Harbor, Saba, Netherlands Antilles (17° 36.907N, 63° 14.938W); 24 males, May–August 2010–2011, Lameshur Bay, St. John, US Virgin Islands (18°18’59.32”N, 64°43’24.5”W), American Museum of Natural History (Crustacea Cat. No. 20223).
Hosts. French grunt, Haemulon flaviolineatum (Desmarest, 1823); Bluestripe grunt, H. sciurus (Shaw, 1803); White grunt, H. plumieri (Lacepede, 1801); Schoolmaster snapper, Lutjanus apodus (Walbaum, 1792); Mangrove snapper, L. griseus (Linnaeus, 1758); Red hind, Epinephelus guttatus (Linnaeus, 1758); Longspine squirrelfish, Holocentrus rufus (Walbaum, 1792), Longfin damselfish, Stegastes diencaeus (Jordan and Rutter, 1897); Threespot damselfish, Stegastes planifrons (Cuvier, 1830); Ocean surgeon, Acanthurus bahianus Castelnau, 1855; Foureye butterflyfish Chaetodon capistratus Linnaeus, 1758; Princess parrotfish, Scarus taeniopterus Desmarest, 1831; Redband parrotfish Sparisoma aurofrenatum (Valenciennes, 1840).
Diagnosis. Eyes large, 0.28 times length of cephalosome. Frontal border produced with conical superior fronto-lateral processes and an inferior conical medio-frontal process which is slightly sunken. Mandible 0.8 times length of cephalosome with 10 to 11 processes on dentate blade. Appendix masculina absent.
Male description (Figs 1 A–F, 2A–C, 3A–E)
Description. Size: Total length of holotype: 3.3 mm. Total length of paratypes: 2.6–3.7 mm (3.0± 0.6 mm, n=10).
Cephalosome (Fig. 1 A, B) rectangular, 1.4 times as wide as long, dorsal sulcus shallow, half length of cephalosome, lateral margins slightly convex, central area slightly concave, posterior margin convex, with central area concave. Eye slightly less than one-third of cephalosome (Fig. 1 B). Many granules distributed dorsally and laterally around eyes, as well as on the dorsal surface of cephalosome. Longer plumose setae concentrated around the dorsal surface around eyes. Median tubercle prominent with granules distributed randomly on dorsal surface (Fig. 1 B). Frontal border (Fig. 1 B) slightly produced. Superior fronto-lateral processes conical, with 3 to 4 long, simple setae on each process, inferior medio-frontal process conical with concave central area. Pereon (Fig. 1 A) with numerous cuticular extensions, few long simple setae and pectinate scales on anterior, lateral and posterior margins of all pereonites. Pereonites 2 and 3 of similar size, widest part of the body, almost as wide as pereonite 5, lateral margins pointing anteriorly. Pereonite 4 with prominent anterior constriction. Pereonites 5 and 6 not fused, both at least twice as long as other pereonites. Pereonite 6 posterior margin concave, with lobi laterales, no lobuii. Pereonite 7 small, dorsally visible with rounded posterior margin, overlapping first pleonite.
Antenna 1 (Fig. 1 C) first article of peduncle with 2 plumose setae distally, second article with 1 plumose seta and 4 to 5 simple setae distally, third article with 8 to 9 simple setae distally, all three articles randomly covered with pectinate scales. Flagellum with 5 articles, about 0.96 times as long as article 3 of peduncle, first article with 3 simple setae distally; article 3 with 1 long aesthetasc seta and 1 simple seta, article 4 with one aesthetasc seta, article 5 terminating in one aesthetasc and three simple setae.
Antenna 2 (Fig. 1 D) about 1.5 times longer than antenna 1, peduncle article 1 with single plumose seta distally; article 3 with single proximal seta, single plumose seta and 7 to 8 long simple setae distally, article 4 with 8 to 9 simple setae along lateral margins, 4 distal plumose setae and 8 to 9 simple setae distally, all 4 articles randomly covered with simple setae and pectinate scales, flagellum with 7 articles, flagellum about 1.4 times as long as peduncle article 4.
Mandible (Fig. 1 A, B, E) 1.6 times as long as wide, more than two-thirds length of the cephalosome, narrow basal neck, curved inwards with 10–11 strong denticulations on the dentate blade, single seta between each process. Strong incisor present, single long simple mandibular seta extending out of the carina. Pectinate scales randomly on dorsal surface of dentate blade.
Maxilliped (Fig. 2 A) proximal article largest with single lateral endite just reaching article 3. Outer margin of proximal article with cuticular extensions. Distal 4 articles bearing plumose setae on lateral margins in order of 6- 6-5-7, mesial borders with short, simple setae. Palp 2.8 times as long as wide. Coupling hooks absent.
Pylopod (Fig. 2 B) convex mesial border fringed with 29–30 long, plumose setae, short, simple lateral and proximal setae; 5 long simple setae distally on posterior surface. Article 1 with 3 areolas increasing in size proximally. Article 2 oval, 1.2 times as long as wide, margins setose, 4 long simple setae distally on posterior surface and single setae mid-laterally. Article 3 minute, with fringing simple setae.
Pleon and pleotelson less than third of total body length, epimera dorsally visible on all pleonites. Numerous simple setae and pectinate scales on lateral and dorsal surface of all pleonites.
Pleotelson (Fig. 1 G) wider than long, lateral margins slightly convex with central margins concave, dorsal surface with two pairs of simple setae, many pectinate scales on dorsal surface, distal apex terminating in pair of simple setae.
Pereopods (Fig. 3 A–E) 2–6 similar in shape. Numerous long setae on basis of all pereopods; pereopod 3 basis with 2 plumose setae anteriorly; pereopods 5 and 6 basis with 1 and 2 posterior plumose setae respectively (Fig. 3 B). Carpus of pereopod 2 with single serrate seta posteriorly and pereopod 6 carpus with single serrate setae anteriorly. Propodus of pereopod 3 with single plumose seta distally. All pereopods with pectinate scales randomly distributed over surface.
Pleopod 2 (Fig. 1 F) endopod longer and wider than exopod, endopod with 8 plumose setae and exopod with 9 plumose setae, lateral margins of endopod and exopod covered with short simple setae. Sympodite with 2 retinaculae on medial margin and single simple seta on opposite margin, surface covered with pectinate scales. Appendix masculina absent. Pleopods 1, 3–5 similar to pleopod 2.
Uropodal (Fig. 1 G) endopod extending beyond apex of pleotelson, exopod reaching apex. Endopod longer and wider than exopod, with 7 long plumose setae, exopod with 5 to 6 plumose setae; pectinate scales on lateral margins of endopod and exopod. Uropodal basis with single simple seta and covered with pectinate scales.
Adult female description (Figs 4 A–F, 5A–B, 6A–E)
Description. Size: Total length of paratypes: 2.1–3.1 mm (2.6± 0.5 mm, n=8).
Cephalosome (Fig. 4 A, B) rectangular, short and broadened, 1.2 times as wide as long. Eyes almost half the length of cephalosome. Frontal border (Fig. 4 B) broadly rounded, produced, slightly concave anteriorly. Pereon (Fig. 4 A) swollen, covered with numerous long simple setae and cuticular extensions on lateral and dorsal surface, sutures between pereonite 5-7. Pereonites 4 and 5 with areae laterales at leg attachment. Pereonite 6 with lobi laterales. Pereonite 7 dorsally visible, small with rounded posterior margin, overlapping first pleonite. Most setae on lateral and anterior margins of pereonites.
Antenna 1 (Fig. 4 C) few short, simple setae on distal end of article 1 and 2, peduncle article 2 with single plumose seta distally; 8 to 9 simple setae distally on third peduncle article. Flagellum 1.4 times as long as article 3 of peduncle, aesthetasc setae similar to those of male, article 4 terminating in 2 to 3 long, simple setae.
Antenna 2 (Fig. 4 D) peduncle article 1 and 2 with few simple setae on the distal end, article 3 and 4 with 5 to 7 setae distally. Peduncle articles of both antennae covered with pectinate scales.
Maxilliped (Fig. 5 A) base and palp of 5 articles. Endite not reaching article 2 of palp. Palp bearing plumose setae on lateral margins in order of 4-4-3-5-7. Article 5 of palp with 4 simple setae distally. Coxa with attached oostegite broader and slightly longer than the palp. Mesial borders of basis, oostegite and the palp densely setose. Pylopod (Fig. 5 B) article 1 broad, robust, curved anteriorly, with a simple seta mid-ventrally, article 2 with 4 simple setae distally and article 3 with 4 to 5 long simple setae distally. Oval-shaped oostegite, 1.7 times as long as wide, covers mouthparts ventrally, not surpassing frontal border. Posterior surface of all articles covered with cuticular extensions.
Pleon (Fig. 4 A) and pleotelson more than a third of the total length. Epimera not distinct. Long simple setae at lateral margin and centre of each pleonite and pectinate scales randomly distributed on lateral and dorsal surface of all pleonites.
Pleotelson (Fig. 4 F) wider than long, lateral margins slightly concave with central area convex, dorsal surface with 1 pair of simple setae and many short simple setae and pectinate scales on dorsal surface, distal apex with 2 long, simple setae.
Pereopods (Fig. 6 A–E) 2–6 similar in shape. Similar to that of male. Dorsal and ventral surface of all pereopods randomly covered with pectinate scales.
Pleopod (Fig. 4 E) endopod and exopod both fringed distally with 8 to 9 plumose setae. Retinacula present on sympodite, with single simple seta on the opposite lateral margin. Pleopods similar.
Uropodal (Fig. 4 F) endopod stretching beyond apex of pleotelson, exopod reaching apex. Endopod longer and wider than exopod, both fringed with 7 long plumose setae and covered with pectinate scales. Uropodal basis with single simple seta and covered with pectinate scales.
Third stage praniza (P3) (Figs 7 A–F, 8A–E, 9A–E)
Description. Size: Total length of paratypes: 2.3–3.6 mm (3.2± 0.6 mm, n=10).
Cephalosome (Fig. 7 A) 1.5 times wider than long, posterior margin slightly concave, slightly wider than anterior margin, lateral margins slightly convex. Large, well-developed, oval-shaped, bulbous, compound eyes on lateral margins of cephalosome, almost same length as cephalosome. Medio-anterior margin of cephalosome slightly concave with lateral concave excavations to accommodate first articles of antennae. Tubercles and setae on dorsal surface absent. Labrum (Fig. 7 A) prominent, half as long as cephalosome, semicircular with apical process, anterior margin concave and truncated posterior margin. Ventral parts of labrum gutter-like with central groove, covers mandibles dorsally and laterally. Pereon (Fig. 7 A) wider than cephalosome, 1.8 times as long as wide. Pereonite 2 and 3 similar in size and shape. Pereonite 4 twice as wide as long, lateral sides tapering towards rounded posterior margin, posterior margin stretching over pereonite 5, lateral shields at leg attachment. Pereonite 5 consists of elastic membrane fully expanded in praniza stage with blood meal, bulbous shields present on lateral sides at leg attachment. Pereonite 6 rectangular, with posterior margin slightly concave, lateral shields at leg attachment. Pereonite 7 dorsally visible, small with rounded posterior margin, overlapping first pleonite. No setae present on pereonites.
Antenna 1 (Fig. 7 C) peduncle article 1 with 2 simple setae, article 2 with 5 simple setae distally and article 3 with 3 simple setae distally and single seta mid-laterally. Flagellum with four articles, about 1.5 times as long as peduncle article 3. Article 1 with single seta distally, few setae on article 2 and 3, article 2 with single aesthetasc seta distally, article 4 terminating in single aesthetasc seta and 3 simple setae.
Antenna 2 (Fig. 7 D) peduncle article 1 and 2 with few simple setae, article 3 with single plumose seta and 4 to 5 simple setae distally; article 4 with 5 to 6 distal setae and 2 plumose setae. Flagellum article 7 terminating with 4 simple setae.
Mandible (Fig. 8 A) stout, swollen at base, distal margin styliform with 8 large, triangular teeth, directed backwardly and 2 small teeth at tip.
Paragnath (Fig. 8 E) elongated, gutter-like, terminates in sharp point.
Maxillule (Fig. 8 D) long, slender, swollen at the base, 7–8 small teeth on distal inner margin. Maxillae not visible.
Maxilliped (Fig. 8 C) palp with 3 articles, first article with 6 to 7 small teeth, second article with 5 to 6 simple setae and article 3 terminating in sharp point, with simple seta mid-laterally.
Gnathopod (Fig. 8 B) smaller than pereopods, 7 articles, few simple setae on all articles, 1 tooth-shaped tubercle dustally on third article and a serrate seta distally on the fourth article. Dactylus strongly hooked.
Pleon (Fig. 7 A) and pleotelson about a quarter of the total length, few simple setae on lateral sides of pleonites, few pectinate scales distributed mid-dorsally on each pleonite.
Pleotelson (Fig. 7 F) triangular, longer than wide, anterior and posterior part of lateral margin slightly concave, mid-anterior parts slightly convex. Pair of simple setae on posterior dorsal surface, distal apex terminating in 2 simple setae.
Pereopods (Fig. 9 A–E) similar in shape to male pereopods, but differing in setation and numbers of tubercles.
Pleopod 2 (Fig. 7 E) endopod larger than exopod, both fringed distally with 9 long plumose setae, cuticular extensions on all margins. Sympodite with retinacula and single simple seta on the opposite lateral margin. Pleopods 1, 3 to 5 similar to pleopod 2.
Uropodal (Fig. 7 F) endopod extending to approximately same length as apex of pleotelson, exopod not reaching apex. Endopod longer and wider than exopod, both fringed with long, simple setae. Endopod with 7 mesial plumose setae and exopod with 6 plumose setae. Few pectinate scales on lateral dorsal areas of endopod and exopod. Uropodal basis with one simple seta and anterior-dorsal surface covered with few pectinate scales.
Etymology. The species is named for the famous Caribbean singer, Bob Marley, as this species is as uniquely Caribbean as Bob Marley.
description: Published as part of Farquharson, Charon, Smit, Nico J. & Sikkel, Paul C., 2012, Gnathia marleyi sp. nov. (Crustacea, Isopoda, Gnathiidae) from the Eastern Caribbean, pp. 47-61 in Zootaxa 3381 on pages 48-60, DOI: 10.5281/zenodo.212837