Cold-water corals off Angola as refuge for a new Aeginella species (Crustacea: Amphipoda: Caprellidae) Author Zettler, Michael L. Author Freiwald, André Author Guerra-García, José M. text Zootaxa 2018 2018-08-29 4462 4 535 546 journal article 29384 10.11646/zootaxa.4462.4.6 64a446eb-b7c8-4685-a80b-70830e4419a4 1175-5326 1441837 EE3A6EB4-6731-439D-A79B-2BF96722AB8C Aeginella corallina sp. nov. ( Figs 2–6 ) Type material. Holotype, mature male, 8.9 mm (used for description and drawings of lateral view, antennae, gnathopods, mouthparts, pereiopods 3–7 and abdomen) (vial: ZMB 31309), Scary mound at 374–375 m water depth at 9.82286°S and 12.77381°E, South Atlantic off Angola, associated to hexactinellid sponges ( Sympagella sp. and Aphrocallistes sp.) within a Lophelia pertusa gallery, leg. 22nd January 2016 . Paratype “1”, mature female, 7.3 mm (used for description and drawings of lateral view, antennae, gnathopods, mouthparts, pereiopods 3–7 and abdomen) (vial: ZMB 31310), collected together with the holotype . Paratype “2”, immature male, 6.2 mm (vial: ZMB 31311), part of the bulk from ROV dive and could not be associated to a specific subsample, same data as holotype . Paratype “3”, mature male, 8.6 mm (vial: ZMB 31312), Valentine Mound at 500 m water depth at 9.72833°S and 12.71460°E , South Atlantic off Angola , associated to a hydroid which was attached to a dead Madrepora branch, 17th January 2016 . Type locality. Scary Mound at 374–375 m water depth at 9.82286°S and 12.77381°E , South Atlantic off Angola . Diagnosis. Head with a dorsal acute projection. Pereonite 1 smooth. Pereonite 2 with a pair of dorsal acute projections anteriorly, one projection distally, and lateral acute projections (one in each side) near the coxa of gnathopod 2. Basis and ischium of gnathopod 2 with a distal projection. Propodus of gnathopod 2 very setose in males, provided with one proximal projection and 2 large distal projections. Distal article of the mandibular palp with 4 or 5 setae. Etymology . The species is named with reference to the cold-water corals habitat in which it was found. Description. Holotype male ( 8.9 mm ). Lateral view ( Figs 2 and 3 ). Head with dorsal acute projection. Pereonite 1 lacking projections. Pereonite 2 with a pair of dorsal acute projections anteriorly, and one projection distally, and lateral acute projections (one in each side) near the coxa of gnathopod 2. Pereonite 3 with ventral lateral projections (one in each side of the pereonite), two medial and 1 distal projections. Pereonite 4 similar to pereonite 3 but lacking distal projection. Pereonite 5 with two projections proximally and another acute projections distally. Pereonite 6 with two dorsal projections. Pereonite 7 smooth. Gills ( Figs 2 and 3 ). Elongated, length about 1.5 times its width. FIGURE 2. Live specimen (holotype) of Aeginella corallina sp. nov. from cold-water corals at the Scary Mound off Angola. Mouthparts ( Fig. 4 ). (Left mandible and upper lip lost during dissection; left mandible figured for the paratype 1 female , see figure 6) Right mandible with trituritive molar, moderately developed and dentate marginally. Threearticulate palp; medial article provided with two setae; distal article of palp the longest, with a setal formula 1-x- 1, being x=3 (although it could be considered as a formula 1-x- 0 with x=4); incisor five-dentate, lacinia mobilis looking like a blade, followed by two more blades; no sign of molar flake. Lower lip without setae; inner lobes with rounded margin. Maxilla 1 outer lobe carrying seven spines distally serrate, palp two-articulate, distal article with four apical setae and three medial setae. Maxilla 2 inner lobe slightly shorter than outer lobe, both with abundant setae apically. Maxilliped inner plate oval, carrying two short spines and several plumose setae; outer plate oval and elongate, with two apical plumose setae and several media non-plumose setae; palp four-articulate, scarcely setose, distal article (dactylus) slightly curved. Antennae ( Figs 2 , 3 and 5 ). Peduncle of antenna 1 of the same length that head and pereonites 1 and 2 combined; second article the longest; flagellum with 16 articles. Antenna 2 as long as the peduncle of antenna 1; proximal peduncular article with a well-developed acute gland cone distally; swimming setae absent; flagellum two-articulate. Gnathopods ( Figs 2 , 3 and 5 ). Gnathopod 1 basis of the same length than the combination of ischium, merus and carpus; grasping margin of propodus smooth; two proximal grasping spine, dactylus bifid distally. Gnathopod 2 inserted on the anterior end of pereonite 2; basis shorter than pereonite 2, with a distal acute projection; ischium rectangular with a distal acute projection; merus rounded; carpus short and rectangular; palm of gnathopod 2 propodus very setose, with proximal projection provided with one grasping spine, and two large projections distally. Pereopods ( Figs 2 , 3 and 5 ). Pereopod 3 and 4 absent. Pereopods 5-7 increasing in robustness, attached to the distal end of pereonites, six-articulate, setose and provided with two grasping spines proximally. Penes ( Fig. 4 ) large, situated laterally, distinctive, oval, length ca. 2 times its width. Abdomen ( Fig. 4 ) with a pair of uniarticulate appendages situated laterally, two lateral lobe and a single dorsal lobe provided with two plumose setae. Paratype female “1” ( 7.3 mm ) ( Figs 3 , 6 and 7 ). Similar to the male except for the following characteristics: presence of oostegites on pereonites 3 and 4, both scarcely setose; pereonites 3 and 4 lacking acute dorsal projections; pereonite 4 lacking proximal lateral acute projections; gills smaller than in male and gills on pereonite 3 larger than gills on pereonite 4; gnathopod 2 propodus smaller and less setose than in male, distal projections scarcely developed; abdominal appendages smaller than in male and less setose.