A study of triphorid larvae and post-larvae at the Campos Basin deep-sea floor, southeastern Brazil (Gastropoda: Triphoroidea). Issue 15 (26th April 2017)

• Record Type: Journal Article
• Authors: Fernandes, Maurício Romulo; Pimenta, Alexandre Dias
• Is Part Of: Journal of natural history. Volume 51:Issue 15/16(2017)
• Page Start: 867
• Page End: 881
• Publication Date: 2017-04-26
• Subjects: Triphoridae -- Oceanprof -- larval wastage -- mass effect -- mid-water metamorphosis; Natural history -- Periodicals; 508
• DOI: 10.1080/00222933.2017.1293178
• Languages: English
• ISSNs: 0022-2933

Abstract

ABSTRACT: 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 larvae and a few post-larvae were profusely sampled at the slope, leading us to three main questions: (1) What species of Triphoridae do these larvae belong to? (2) Why were so many triphorid larvae found at the site? and (3) What does the presence of post-larvae mean? We show that all the larvae belong to genera or species present in the Campos Basin continental shelf. Some speculations are made about the great abundance of larvae in the slope, especially to vertical migrations of larvae, and about mesh size, in addition to possible differences of larval ecology between triphorids and the closely related Cerithiopsidae. Two possible explanations are indicated for the presence of post-larvae: mass effect (formation of pseudopopulations) or mid-water metamorphosis (spontaneous metamorphosis at the water column), with the latter being the more likely scenario. Despite being essentially theoretical, the present study aims to develop new insights into the larval ecology of these small gastropods, and to furnish a base for future tests.