Byblis bjornbergae, Valério-Berardo, Maria Teresa, 2008

Valério-Berardo, Maria Teresa, 2008, Six new species of deep water Ampeliscidae (Crustacea: Amphipoda) from Brazilian Coast, Zootaxa 1844, pp. 1-24 : 17-20

Byblis bjornbergae sp. nov.

( Figs. 9–10 )

Material examined: Holotype: 1 female, 4.2mm, 22°10’43,278”S – 39°54’46,036”W- 750 meters, R/V Astro Garoupa, 10/XII/2002, MNRJ 20540; Paratypes: 1 male 22°04’33,9”S –39°52’ 05,1W, 1050 meters, R/V Astro Garoupa, 30/VI/2003 MNRJ 20104; 1 female, 22°10’43,278”S – 39°54’46,036”W- 750 meters, R/V Astro Garoupa, 10/XII/2002, MNRJ 20540

Others material examined: 1 female, 21°52’59,2”S – 39°55’32,2”W, 750 meters, R/V Astro Garoupa, 29/VI/2003, MNRJ 20528; 1 female, 22°24’31,58”S – 39°57’28,05”W, 1050 meters, R/V Astro Garoupa, 20/ XI/2002, MNRJ 20095; 2 females, 22°04’32,8”S – 39°54’11,4”W, 750 meters, R/V Astro Garoupa, 30/VI/ 2003, MNRJ 20527; 2 females 22°36’03,00”S – 40°21’45,36”W, 750 meters, R/V Astro Garoupa, 22/XI/2002, MNRJ 20536; 3 females, 22°10’53,4”S – 39°52’18,3”W, 1050 meters, R/V Astro Garoupa, 1/VII/2003, MNRJ 20108; 1 female, 22°26’28,8”S – 39°58’53,3”W, 1050 meters, R/V Astro Garoupa, 20/VI/2003, MNRJ 20101; 1 female, 22°10’53,4”S – 39°52’18,3”W, 1050 meters, R/V Astro Garoupa, MNRJ 20098.

Etymology: Named in tribute to Dr Tagea Kristina Sinon Bjornberg, in recognition of her significant contribution to Brazilian carcinology

Diagnosis: Head anterior margin acutely produced below insertion of antenna 1, anteroventral corner oblique. Two pairs of eyes weakly developed. Antenna 1 subequal in length to antenna 2. Antenna 2 about half body length. Pereopod 7 basis posterior margin oblique, postero-ventral corner sharply pointed, carpus with 3 robust setae on anterior margin and 2 robust setae on postero- distal corner; propodus 1.2X carpus length, dactylus 0.8X propodus length with a seta at the distal point. Epimera 1 and 2 ventral margins with 2 and 1 short setae respectively. Uropod 3 outer ramus 1.2X inner ramus length, with 2 robust setae on outer margin, inner margin with a spine and mid- distal portion serrate; inner ramus with 3 facial robust setae. Telson as wide as long apical margin truncate and serrate, with dorsal robust and simple setae, cleft 1/3 length. Male: Antennae longer than female and bear brush setae. Uropod 3 rami inner margins with plumose setae. Telson elongate, 1.6X longer than wider, cleft less than 1/3.

Description: Holotype, female 4.2mm. Head ( Fig. 9 ) about 1.2X deeper than longer, anterior margin acutely produced below insertion of antenna 1, anteroventral margin oblique. Two pairs of eyes weakly developed. Antenna 1 ( Fig. 9 ) subequal in size to antenna 2, peduncular article 2, 3X longer than article 3; flagellum longer than peduncle and with 11 articles. Antenna 2 ( Fig. 9 ) about half body length, peduncular article 5 1.2X longer than article 4; flagellum longer than peduncle, with 8 articles. Mandible ( Fig. 9 ) with 5 accessory of setae row; palp article 1 1.5X article 3, article 2 very long and 3.8 X article 3, with pectinate setae on inner margin, article 3 with subapical and apical pectinate setae. Maxilla 1 ( Fig. 9 ) inner plate with 2 apical setae; outer plate with 8 serrate robust setae; palp article 2 with 5 robust setae and 7 simple setae on distal margin. Maxilla 2 ( Fig. 9 ) both plates with apical plumose setae. Maxilliped ( Fig. 9 ) inner plate distally rectangular, with 2 robust setae and plumose setae on apical margin; outer plate exceeding to end of the article 2 palp, with 3 chisel-shaped setae, 6 robust setae along inner margin, 3 simple setae and 1 pinnate seta on apical margin; palp articles 3 and 4 with simple setae on distal margins.

Coxae 1–3 ( Fig. 9 ) longer than broad, ventral margins smooth; coxae 1 and 2 with plumose setae on distal margin, coxa 4 concave posteriorly, postero-distal corner rounded hook-shaped. Gnathopod 1 ( Fig. 9 ) basis inflated distally, anterior margins with setae and smooth; carpus 1.2 X propodus length, both with posterior margins with pinnate setae, dactylus with 6 setules along inferior margin. Gnathopod 2 ( Fig. 9 ) basis inflated distally, anterior and posterior margins smooth, with simple setae on anterior margin; merus with simple setae on posterior margin; carpus longer than propodus (1.1 X), both articles with pinnate and simple setae along posterior margins; dactylus slightly curved, inferior margin smooth. Pereopod 3 and 4 ( Figs. 9 and 10 ) similar in shape but third pereopod is more massive and less setose than fourth. Pereopod 3 basis stout, breadth 0.3X length, midproximal margin wider than distal margin, with robust setae on both margins; merus 0.8X basis length, with subapical plumose setae on posterodistal margin; carpus as long as wide; carpus and propodus with plumose setae on posterior margins; dactylus smaller than carpus and propodus length combined (0.8 X). Pereopod 4 basis slender, breadth 0.2 X length; basis and isquium with simple setae on posterior margins; merus longer than basis, with 3 long setae on half posterodistal margins; merus, carpus and propodus with plumose setae along posterior margin; carpus as long as wide; propodus with simple setae on anterior margin; dactylus smaller than carpus and propodus length combined (0.7 X). Pereopod 5 ( Fig. 10 ) basis slightly lobate posteriorlly, with short robust setae on anterior margin; carpus longer than propodus (1.2 X), with a comb of robust setae on posterior margin, produced posterodistally bearing 2 robust setae and 2 long setae on posterodistal corner; carpus and propodus with long simple setae on anterior margin; dactylus simple, very short, curved. Pereopod 6 ( Fig. 10 ) basis, enormous, ovoid, anterior margin with 6 short plumose setae; carpus longer than propodus (1.3 X) and produced posterodistally, posterior margin with a comb of robust setae, posterodistal corner bearing 2 robust setae and 1 long simple setae; carpus and propodus with robust setae along anterior margins; dactylus simple, short and curved. Pereopod 7 ( Fig. 10 ) basis posterior margin oblique, posteroventral corner sharply pointed, just reaching to distal margin of carpus, all posterior margin fully setose with plumose setae; ischium shorter than merus (0.8 X); merus with long plumose setae along posterior margin, smooth posteriorly; carpus with 3 robust setae along anterior margin and 2 robust setae on posterodistal corner; propodus longer than carpus (1.2 X), with 3 robust setae along posterior margin and 1 robust setae on posterodistal corner; dactylus shorter than propodus (0.8X), with a seta at the distal point.

Epimera 1 and 2 ( Fig. 9 ) ventral margins with 2 and 1 short robust setae, respectively. Uropod 1 ( Fig. 10 ) reaching to end of uropod 2 rami, peduncle subequal in length to outer rami, with 3 robust setae on inner margin; inner ramus slightly shorter than outer ramus, with 3 robust setae along inner margin; outer ramus with 1 robust setae on inner margin. Uropod 2 ( Fig. 10 ) peduncle longer than rami (1.4 X), with 1 robust seta on inner margin; inner ramus slightly longer than outer ramus, with 1 robust seta on inner margin. Uropod 3 ( Fig. 10 ) peduncle with a robust setae on inner margin; outer ramus longer than inner ramus (1.2 X), with 2 robust setae on outer margin, inner margin with a spine and middistal portion serrate; inner ramus with 3 facial robust setae. Telson ( Fig. 10 ) as wide as long apical margin truncate and serrate, with dorsal robust and simple setae, cleft 1/3 of length.

Male 5.3mm. Antennae longer than female and bear brush setae. Uropod 3 ( Fig. 10 ) rami inner margins with plumose setae. Telson ( Fig. 10 ) elongate, length1.6 X breadth, cleft less than 1/3 of length.

Remarks: Byblis bjornbergae sp.nov. is similar to the B. daleyi ( Giles, 1890) and B. erythrops Sars, 1883 in having weakly developed eyes, pereopod 7 with the posterior margin oblique and posteroventral corner sharply pointed and telson 1/3 cleft. However, Byblis bjornbergae sp. nov. is differentiated from B. daleyi by the subequal length of the antennae and not antenna 1 shorter than antenna 2, diagnostic characteristic of B delayei . In relation to B. erythorps , Byblis bjornbergae sp. nov. can be distinghished for having antennae shorter than 1/3 of the length of the body, with 5–7 flagellum articles, whereas in B. erythrops the antennae are very long exceeding ½ of the length of the body and flagellum 35-articulate; uropod 3 with only 1 spine on the inner margin of the inner ramus (versus 5 spines in B. erythrops ).

Figures

FIGURE 9. Byblis bjornbergae sp. nov., holotype female, 4.2 mm (MNRJ 20540). Scale bars = 0.1 mm, unless indicated otherwise.

FIGURE 10. Byblis bjornbergae sp. nov., holotype female, 4.2 mm (MNRJ 20540); paratype male 5.3 mm (MNRJ 20104). Scale bars = 0.1 mm.