Domingos Celso, Moraes Fernando, Muricy Guilherme
Departamento de Invertebrados, Museu Nacional, Universidade Federal do Rio de Janeiro. Quinta da Boa Vista s/n, Sao Cristovao, Brasil.
Zootaxa. 2013;3718:530-44. doi: 10.11646/zootaxa.3718.6.2.
Seven species of Plakinidae are currently known from Brazil, belonging to genera Plakina (P. trilopha), Plakinastrella (P. microspiculfera, P. onkodes), and Plakortis (P. angulospiculatus, P. halichondrioides, P. insularis, and P microrhabdifera). In this study we describe four new species of the genera Plakinastrella and Plakortis, increasing the number of plakinid species in Brazil to eleven. Plakortis petrupaulensis sp. nov. is encrusting, light brown; the skeleton is disorganized with few traces of reticulation; lacunae are absent; the spicules are diods and tuberculate microrhabds; spheres are common and triods are absent. Plakortis spinalis sp. nov. is encrusting, gray, cartilaginous, has a reticulated ectosomal skeleton, and is distinguished by the spines in some of the diods and triods; microrhabds are also tuberculate and smooth spheres are common. Plakortis potiguarensis sp. nov. is encrusting, brown with gray tinges, and cartilaginous; the skeleton is disorganized and scarce, composed of thin, irregular diods, triods and relatively large microrhabds. Plakinastrella globularis sp. nov. has a globular shape and dark blue color in vivo; the ectosomal skeleton has a double tangential reticulation and the choanosomal skeleton is reticulated. The spicules are diods, triods, calthrops and microrhabds; spheres are common. Two of the new species have characters previously unknown in their respective genera: the spined diods and triods of Plakortis spinalis sp. nov. and the blue color and microrhabds of Plakinastrella globularis sp. nov. The presence of microrhabds in Plakinastrella suggests a close relationship of this genus with Plakortis.
目前已知巴西有7种扁海绵科动物，分属于扁海绵属（三棱扁海绵）、扁星海绵属（微刺扁星海绵、瘤扁星海绵）和扁盘海绵属（角刺扁盘海绵、海胆扁盘海绵、岛扁盘海绵、微棒扁盘海绵）。在本研究中，我们描述了扁星海绵属和扁盘海绵属的4个新物种，使巴西扁海绵科物种数量增加到11种。保罗港扁盘海绵新种呈壳状，浅褐色；骨骼结构紊乱，几乎没有网状痕迹；无腔隙；骨针为双盘状和瘤状微棒；球体常见，无三盘状骨针。棘扁盘海绵新种呈壳状，灰色，质地似软骨，体表骨骼呈网状，其特征是部分双盘状和三盘状骨针上有刺；微棒也有瘤状，光滑球体常见。波蒂瓜尔扁盘海绵新种呈壳状，褐色带灰色调，质地似软骨；骨骼结构紊乱且稀少，由细的、不规则的双盘状、三盘状骨针和相对较大的微棒组成。球状扁星海绵新种活体时呈球状，深蓝色；体表骨骼有双切向网状结构，中胶层骨骼呈网状。骨针为双盘状、三盘状、十字骨针和微棒；球体常见。其中两个新物种具有其各自属中以前未知的特征：棘扁盘海绵新种的带刺双盘状和三盘状骨针，以及球状扁星海绵新种的蓝色和微棒。扁星海绵属中微棒的存在表明该属与扁盘海绵属关系密切。
