Comments on brazilian Halichondria Fleming (Halichondriidae, Halichondrida, Demospongiae), with the description of four new species from the São Sebastião Channel and its environs (Tropical Southwestern Atlantic)

Abstract

Halichondria Fleming, 1828 is a genus which poses special challenges to the porifera taxonomist due to a shortage of conspicuous anatomical characters. Species may have one or more categories of oxeas, frequently hard to tell apart, di stributed in a criss-crossed pattern , where spicular tracts are seldom vi sible. Such absence of a pattern is known as the halichondroid architecture.There are nevertheless over 70 species described for the who le world, and the detai led study of these records has gained some momentum with the discovery of biologically active metabolites in some Halichondria (e.g. MUNRO et af. 1994). For the Brazilian coast, six species were cited previously (DE LAUBENFELS 1956;JOHNSON 1971 ; HECHTEL 1983; MURJCY et af. 1991 ;LERNER 1996; MURJCY & MORAES 1998), viz. Halichondria ("Menanetia") Hechtel , 1965. The status of these records will be discussed below. It is the purpose of this article to describe four new species found in the Sao Sebastiao Channel area. MATERIAL AND METHODSSpecimens were studied in situ whenever possible. The underwater photographs were taken by the senior author with a Nikonos V underwater camera and a close-up kit (close-up lens or extension tubes). Size classes for the range of possible spicule lengths were obtained by using the classic Sturges' algorithm (I + 3.310gtl, where "tl" is the range between largest and smallest lengths). They were collected with a diver' s knife through scuba diving or wading at low tide. Preparations of

Morphological description of six species of Suberitida (Porifera: Demospongiae) from the unexplored north-eastern coast of Brazil, with emphasis on two new species

“…In this sense, the species significantly differs from all other species recorded in the Tropical Western Atlantic by the presence of oxeas larger than 1200 μm, especially H. ( H. ) melanadocia , the most similar congener. The other four Brazilian species are exclusive to the Western Temperate South-eastern Atlantic (see Carvalho & Hajdu, 2001) and do not share external or internal morphological traits.…”

Sponges as substrata and early life history of the tubulariidZyzzyzus warreni(Cnidaria: Hydrozoa) in the São Sebastião Channel, Brazil

“…americana were observed to prey upon actinulae of Z. warreni during laboratory experiments. The association of H. cebimarensis with ophiuroids, tubeworms, ectoprocts, Sargassum and calcareous algae (Carvalho & Hajdu 2001) could affect the successful settlement of Z. warreni.…”

Filter-Feeding in Marine Invertebrates

“…panicea is genetically distant from and forms a sister group to a species complex consisting of European H. panicea and H. bowerbanki [53]. Halichondria panicea has also been reported from the Tropical Southwestern Atlantic, along with other species such as H. magniconulosa Hechtel (1965) [68], H. cebimarensis, H. tenebrica, H. migottea, H. sulfurea Carvalho & Hajdu (2001) [59] and H. marianae Santos et al (2018) [69]. Common species in the Pacific Ocean are H. japonica [65], H. okadai, H. oshoro [70], H. gageoenesis and H. muanensis Kang & Sim (2008) [42], while H. panicea and H. bowerbanki have been reported from Alaska [63,64] and Korea [66], respectively.…”