Carlo M. Cunha

A new species of Acteon (Opisthobranchia: Acteonidae) from Northeast Brazil

A new species of Acteon Montfort 1810, Acteon mirim sp. nov., from Canopus Bank, state of Ceara, Brazil is described based on shell morphology. The new species is compared with other species of the genus reported from Brazil. It differs from other Brazilian species in having a whitish color with dark orange-brown spiral bands and a shell surface covered with small spiral grooves, regularly rectangular.

Taxonomic revision of the orthalicid land snails (Pulmonata: Stylommatophora) from Trindade Island, Brazil

Land snails (stylommatophoran pulmonates, shells only) were collected on Trindade Island, ∼1140 km off Vitória, Brazil, by the Marion Dufresnei Expedition (MD-55) and more recently by our team. Trindades endemic snails are Bulimulus brunoi and Naesiotus arnaldoi (Orthalicidae), and Oxyloma beckeri and Succinea lopesi (Succineidae). As some non-native species have also been found, a taxonomic revision of the native fauna was needed. Here, the revision is focused on orthalicids, presenting updated descriptions and diagnosis. Moreover, the supposed native orthalicid Bulimulus trindadensis is deemed here to be a Subulinidae, and the new genus Vegrandinia is erected to accommodate it. Trindades insular environment is delicate and very susceptible to invasive species. No living specimens of these taxa, native or non-native, have been collected since before the MD-55 Expedition. However, it is still premature to assume that the introduced species have failed to establish themselves or that the native species are now extinct. http://www.zoobank.org/urn:lsid:zoobank.org:pub:6B1D6F63-EFB0-400A-8C0C-B508EAEB0A4B

Rediscovery of Brazilian corambids (Gastropoda: Onchidorididae)

Three specimens of the genus Corambe were found in the intertidal zone of Santos, Sao Paulo (Brazil); two of them were identified as C. evelinae and one as C. carambola . Both species are reported for the first time since more than about 40 years ago.

Rediscovery of Gastropteron chacmol (Gastropoda: Gastropteridae) on the Brazilian coast

Gastropteron Kosse, 1813 is a genus of smal l cephalaspidean gastropods of the family Gastropteridae, a group which comprises four genera and circa 40 species distributed worldwide. Only two species of Gastropteron are known from the Western Atlantic: G. chacmol Gosliner, 1989, previously identified as the Mediterranean G. rubrum (Rafinesque, 1814) by Abbott (1974), who reported it as Bmoderately common^ from Texas, Florida and the West Indies to Brazil; and G. vespertilium Gosliner & Armes, 1984, endemic to Florida, USA. The report of G. chacmol by Marcus and Marcus (1960), at that time identified as G. rubrum, was the first reference to the species in Brazilian waters, more specifically from São Paulo state (they also reported it from Florida and Guadeloupe). Later, Gosliner (1989) described G. chacmol from Quintana Roo, Mexico. This species closely resembles G. rubrum and G. vespertilium: all have an elongate flagellum on the right side of the body and radular inner lateral teeth with numerous small denticles. Both Western Atlantic species, G. chacmol and G. vespertilium, share the reddish ground color, but in G. chacmol the red is deeper and richer, and the parapodial margin is bright yellow; the siphon and flagellum are of the same ground color, without any additional pigment. Gosliner (1989) set the above-mentioned distribution of the species based on the report of Marcus and Marcus (1960), and by considering all Western Atlantic records of G. rubrum as being G. chacmol. Since then, there have been no further reports of the species from Brazil (besides a misidentification by Rios 2009), and no image of living specimens are known from this region. The single specimen reported herein (length of living animal: 4.1 mm) was collected on a gravel bottom, at a depth of 6–7 m, on Itaçucê Island, São Sebastião, São Paulo state. The material was preserved in ethanol 70 % and deposited in the collection of the Museu de Zoologia da Universidade de São Paulo (MZSP 109683, A. Migotto coll. 15/xi/2011). When placed on a Petri dish, the animal alternated between crawling and swimming, the latter lasting only a few seconds (Fig. 1, Online Resource 1). Despite Brazil’s nearly 8,000-km coastline and the increase in the number and scope of collections in recent years, this is the first record of this Communicated by V. Urgorri

Taxonomical study on the mollusks collected in Marion-Dufresne (MD55) and other expeditions to SE Brazil: the Fissurellidae (Mollusca, Vetigastropoda)

The Fissurellidae collected by the Marion-Dufresne Expedition, as well as other regional expeditions to SE Brazil are examined taxonomically, treating 21 species, of which 20 are new. The following new species are described (order according to depth range; species marked with * are from expeditions other than MD55): Cornisepta uirapa (790-940 m), Cornisepta arrepiata (295-1,050 m), Cornisepta aninga (295-1,050 m), Cranopsis hycavis (637 m), Cranopsis nymphalis (295 m), Cranopsis enigmatica (790-940 m), Cranopsis cearensis* (250 m), Cranopsis apostrema (110-940 m), Cranopsis alaris (250-450 m), Cranopsis canopa* (250 m), Cranopsis columbaris* (250 m), Emarginula suspira (54-940 m), Emarginula icosisculpta (10-12 m), Manganesepta atiaia (950-1,570 m), Profundisepta denudata* (3,000 m), Puncturella volcano (607-620 m), Rimula leptarcis (85-105 m), Zeidora pussa (607-940 m), Zeidora crepidula (790-940 m), Hemimarginula hemitoma (1-105 m). Diodora mirifica Métivier, 1972 (10-12 m), common in Brazilian oceanic islands, is the only fissurellid species previously known from that area. The genera Cornisepta, Cranopsis, Manganesepta, Profundisepta, Zeidora, and Hemimarginula are reported for the first time from Brazil. Emarginula suspira is named for material that has been misidentified as E. tuberculosa, a Miocene Mediterranean fossil.

It’s not what it looks like: molecular data fails to substantiate morphological differences in two sea hares (Mollusca, Heterobranchia, Aplysiidae) from southern Brazil

Species of sea hares have been recognized traditionally based on morphological traits, mainly the radula, external coloration, and reproductive anatomy. However, recent studies have shown substantial color variation in some sea slug species. Molecular data have been successfully used to differentiate morphologically similar species of “opisthobranchs” and resolve questions on the taxonomic value of color. The objective of this paper is to use molecular data in an attempt to elucidate whether specimens of Aplysia brasiliana with distinct colorations and morphologies are actually the same species. To this end, DNA from 14 specimens of A. brasiliana was extracted, including five specimens identified as a distinct morphotype from typical A. brasiliana. Although the two morphotypes have consistent differences in their external morphology and radula, the molecular data confirmed that there are no significant genetic differences between them. This is another example of the need to re-evaluate taxonomic decisions based on morphology in light of molecular evidence.

First record of the Japanese land snail Ovachlamys fulgens (Gude, 1900) (Gastropoda, Helicarionidae) in Brazil

Laboratorio de Ambientes Insularizados Universidade Estadual Paulista (UNESP) Instituto de Biociencias, Praca Infante Dom Henrique s/no, Parque Bitaru

New species of the genus Elachisina (Gastropoda: Elachisinidae) from northeastern Brazil

The family Elachisinidae Ponder, 1985 includes minute marine gastropods that live predominantly in the sublittoral zone (Ponder & Keyzer 1998; Rolán & Rubio 2001; Rolán & Gofas 2003). Most elachisinids have been included in the genus Elachisina Dall, 1918 based on their shell morphology (Warén 1996; Rolán & Rubio 2001; Rolán & Gofas 2003), consequently, very little is known about the habitat and ecological niche of the species (Ponder & Keyzer 1998; Rolán & Gofas 2003). Elachisina floridana (Rehder, 1943) is the only Atlantic congener collected alive, and is known to live beneath rocks and in rocky crevices in the intertidal zone to about 1 m depth in the Bahamas and Caribbean Sea (Ponder 1985; Ponder & Keyzer 1998; Rolán & Gofas 2003; Redfern 2013). Eastern Atlantic E. canarica (Nordsieck & García-Talavera, 1979) was also collected alive from the Canary Islands, but with no information on the habitat (Rolán & Gofas 2003). The islands of the northeastern Atlantic and West Africa are the regions with the greatest Elachisina richness known, totaling nine species (Rolán & Rubio 2001; Rolán & Gofas 2003). Only E. floridana has been recognized so far to be widely distributed throughout the Western Atlantic (Rolán & Gofas 2003; Rios 2009; Redfern 2013).

Redescription and anatomy of Diplodonta portesiana (d’Orbigny, 1846) (Bivalvia, Ungulinidae) from Brazil

Abstract The present redescription of Diplodonta portesiana (d’Orbigny, 1846) is the first part of the revision of this genus in the East Atlantic. This species, despite being common in the Atlantic coast, remains poorly known. A detailed shell and anatomical study was conducted based not only on specimens from the type locality’s vicinities but also on samples from other regions. Diagnostic characters for Diplodonta portesiana includes: rounded shell with a small ligament; triangular, short and deep nymph; external micro ornamentation composed of small concavities in a concentric pattern; small adductor muscles; reduced pedal gape; pair of long hemipalps with a large area covered by folds; stomach with four ducts leading to digestive diverticula; and long intestine length. Our study suggests at least two new diagnostic characters to the genus: the two pair of muscles that controls the incurrent and excurrent openings and a residual ring-like tissue surrounding the anterior half of the posterior foot retractor muscle.

How mollusk assemblages respond to different urbanization levels: characterization of the malacofauna in subtropical Brazilian mangroves

This study aimed to describe the composition of mollusk assemblages in subtropical Brazilian mangroves with different levels of urbanization in their watersheds. Mangroves are important ecosystems, which are vanishing worldwide due to human impacts. The knowledge about the consequences of human pressure on the fauna of these ecosystems is still incipient. In addition, although Brazil is the country with the second largest mangrove area, there is a lack of studies on the mangrove fauna in this country. Mollusks are the second most abundant group of mangrove invertebrates and can be useful indicators of mangrove health. For this reason, mollusk species were assessed in two mangroves surrounded by a dense human population and in two mangroves away from urban centers. A total of 3820 individuals, representing 15 species, were sampled. The results revealed that the mollusk abundance, diversity estimators, and sediment organic matter content were not good indicators of the effects of urbanization on the mangroves studied. However, the species composition of mollusk assemblages differed according to the urbanization level. This survey of the mangrove malacofauna represents another step toward the effort to investigate and conserve the fauna of these important estuarine environments.