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Simplified hypotheses of metamorphosis occurring at mid-water or at the deep-sea floor. = adult; = larvae; = post-larvae; = dead specimen.
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Triphoridae is a family of marine microgastropods, with hundreds of species described especially from shallow waters, comprising planktotrophic and non-planktotrophic development modes. The present study focusses on an interesting finding of the deep-sea Oceanprof Expedition, conducted in Campos Basin (southeastern Brazil), in which triphorid larva...
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... Triphorids display a huge variation in the composition of the radula (Marshall 1983;Fernandes & Pimenta 2019a), sometimes referred to as "rhinioglossate" because of the presence of several marginal teeth and a peculiar morphological variability of teeth and cusps. Distinctive sculpture of both embryonic and larval shell for species with a multispiral protoconch constitute another remarkable feature of this family (Marshall 1983;Fernandes & Pimenta 2017b). (Olsson, 1916). ...
... In spite of the lack of knowledge about triphorid larval development, C. melanura seems to be the western Atlantic triphorid with the longest larval phase in the open ocean, being the commonest species in the seamounts and islands of the Vitória-Trindade Chain ) and in Campos Basin (southeastern Brazil) offshore waters (Fernandes & Pimenta 2017b). The ability of larvae to cross an ocean does not imply the panoceanic presence of adults owing to difficulties of post-larval survivorship and establishment in the new territory (Bhaud 1998), especially regarding the dietary limitations caused by the feeding mode of triphorids on particular sponges. ...
... A common feature between atypical shells from oceanic islands and deep records is a possibly extended larval period in the water column if there is no habitat for settlement. Fernandes & Pimenta (2017b) suggested that the protoconch of C. melanura has a different color when larvae spend a long period in the water column. At least in northern and part of northeastern Brazil, it is observed that the deeper the site, the more frequent to see atypical shells, perhaps associated to latent effects and stress during an extended larval development (Pechenik 2006). ...
The present study aims to fulfill the gap of taxonomic knowledge on Triphoridae from Brazil. We describe five new species (Isotriphora uncia sp. nov., Isotriphora leo sp. nov., Monophorus verecundus sp. nov., Sagenotriphora albocaput sp. nov., Similiphora lucida sp. nov.), report five species previously known only from the Caribbean and related areas (Cheirodonta dupliniana (Olsson, 1916), Eutriphora auffenbergi Rolán & Lee, 2008, Isotriphora tricingulata Rolán & Fernández-Garcés, 2015, Marshallora ostenta Rolán & Fernández-Garcés, 2008, Monophorus caracca (Dall, 1927) comb. nov.) and describe six morphotypes at the generic level (Isotriphora sp. 1, Marshallora sp. 1, Nanaphora sp. 1, Sagenotriphora sp. 1, Sagenotriphora sp. 2, Similiphora sp. 1). Remarks are made to some species previously recorded from Brazil, including the invalidation of records, problems of generic allocation and geographical range extensions. Maps of the geographical distribution are provided for the 65 currently recognized species of Triphoridae from Brazil. Of these, 31 species are endemic to Brazil and 58 inhabit the continental shelf vs only seven from the continental slope. A distinct geographical zone occurs in southeastern Brazil. A few species occur exclusively near the mouth of the Amazon River, whereas others inhabit a local biogenic reef, possibly serving as a biogeographical corridor that connects western Atlantic populations. Species of Isotriphora from Brazil are particularly common around oceanic islands, probably due to adopting intracapsular metamorphosis, which may have evolved in more than one evolutionary event.
... group, was sampled from shallow-water plankton in Hawaii. Otherwise arguing in favor of a demersal larva or even intracapsular metamorphosis for Inella, Fernandes & Pimenta (2017b) reinforced the absence of shared species of this group between the continent and the Vitória-Trindade Seamount Chain, southeastern Brazil, owing to their presumed absence in the plankton community and consequent lack of larval dispersal towards these seamounts. ...
The triphorid genera Inella and Strobiligera are historically considered to represent one or two distinct groups, with recent studies claiming that Strobiligera comprises species with paucispiral or multispiral protoconchs, whereas only species with paucispiral protoconch occur in Inella. The present study aims to update the taxonomy of Inella and Strobiligera (with paucispiral protoconchs) from Brazil. Three main groups are recognized: Inella s.s. and Strobiligera show a simultaneous emergence of the three spiral cords of the teleoconch, the former possessing a discrete nucleus and the latter bearing a distinct globose protoconch; the “pseudo Inella” group has a late emergence of the median spiral cord of teleoconch. Four species were previously recorded from Brazil: I. unicornium, I. longissima, S. pompona and S. compsa, of which the three latter records are disregarded for being based on shells with broken apices and consequent uncertainty of identification. Twenty species in fact occur in Brazil: Inella s.s. is represented by I. apexbilirata and one possible new species; “pseudo Inella” includes “Inella” differens, “Inella” faberi, “Inella” galo sp. nov., “Inella” euconfio sp. nov., “Inella” leucocephala sp. nov., “Inella” faceta sp. nov., “Inella” maculata sp. nov., “Inella” vanilla sp. nov., and three possible new species; Strobiligera is represented by S. unicornium comb. nov., S. gaesona, S. dinea, Strobiligera campista sp. nov., Strobiligera santista sp. nov., and two possible new species. The “pseudo Inella” group is probably derived from unrelated lineages that converged to a simple type of paucispiral protoconch, requiring the examination of radular morphology to properly reallocate those species. The supposed restricted geographical range of triphorids with lecithotrophic development requires future investigations of the five species from the northwestern Atlantic/Caribbean that are herein recorded to Brazil.
... However, the type material of C. eiseni does not have a protoconch, precluding further comparisons in relation to this structure. The original record of C. eiseni from Galapagos by Hertlein and Strong (1955) requires confirmation, because no shell was figured and cerithiopsids may have a restricted larval dispersal in the open sea when compared to triphorids (Fernandes and Pimenta, 2017b). ...
... cords(Fernandes & Pimenta 2017b), and does not exhibit a simultaneous emergence of the three spiral cords of teleoconch(Fernandes & Pimenta in prep.).Trochus perversusLinnaeus, 1758. Designation by monotypy. ...
The alpha-taxonomy of triphorids is still largely based on the study of the shell, and the scarcity of studies dealing with their anatomy is a result of the difficulty of sampling live animals and their very small size. Whereas radula and operculum are important structures in the taxonomy at the generic level, the jaw of triphorids has never been properly studied, being regarded as presenting a morphological homogeneity. The present research explored the basic anatomy (especially internal hard structures: operculum, jaw and radula) of 12 species from Brazil, distributed in 11 genera: Cheirodonta Marshall, 1983 (with a new generic allocation, Cheirodonta dupliniana (Olsson, 1916) comb. nov.), Cosmotriphora Olsson & Harbison, 1953, Iniforis Jousseaume, 1884, Latitriphora Marshall, 1983, Metaxia Monterosato, 1884, Monophorus Grillo, 1877, Nanaphora Laseron, 1958, Nototriphora Marshall, 1983, Sagenotriphora Marshall, 1983, Similiphora Bouchet, 1985 and Strobiligera Dall, 1924; in addition, the basic anatomy of the Caribbean species “Inella” harryleei Rolán & Fernández-Garcés, 2008 was analysed. Radular examination showed that the majority of species studied is properly allocated in their genera after comparisons in the literature with respective type species, albeit a few species are clearly in need of a new generic allocation. The jaw of triphorids is remarkably heterogeneous, displaying different patterns of scales and micro-pores between outer and inner sides.
The larval shells of Antalis circumcincta (Watson, 1879) (order Dentaliida), Pertusiconcha callithrix (Dall, 1889) (order Gadilida) and of an undetermined species of uncertain systematic position are described. The material studied comprises mainly samples from deep waters, collected by expeditions along the southeast coast of Brazil. The larval shell of the three taxa matches other types previously described in the literature. Antalis circumcincta and P. callithrix have four regions (protoconch A, protoconch B, teleoconch A, teleoconch B), but differ in dimensions and sculpture from each other, while the undetermined species has three regions (protoconch A, protoconch B, teleoconch B). A morphometric approach combined with a discriminant analysis also indicates that the three taxa are significantly distinct. This study confirms patterns of larval shells at the taxonomic rank of orders but other supraspecific patterns remain uncertain.
