The first global deep-sea stable isotope assessment reveals the unique trophic ecology of Vampire Squid Vampyroteuthis infernalis (Cephalopoda)

Vampyroteuthis infernalis Chun, 1903, is a widely distributed deepwater cephalopod with unique morphology and phylogenetic position. We assessed its habitat and trophic ecology on a global scale via stable isotope analyses of a unique collection of beaks from 104 specimens from the Atlantic, Pacific and Indian Oceans. Cephalopods typically are active predators occupying a high trophic level (TL) and exhibit an ontogenetic increase in δ15N and TL. Our results, presenting the first global comparison for a deep-sea invertebrate, demonstrate that V. infernalis has an ontogenetic decrease in δ15N and TL, coupled with niche broadening. Juveniles are mobile zooplanktivores, while larger Vampyroteuthis are slow-swimming opportunistic consumers and ingest particulate organic matter. Vampyroteuthis infernalis occupies the same TL (3.0–4.3) over its global range and has a unique niche in deep-sea ecosystems. These traits have enabled the success and abundance of this relict species inhabiting the largest ecological realm on the planet.Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. The attached file is the published pdf

Reproductive system and the spermatophoric reaction of the mesopelagic squid Octopoteuthis sicula (Rüppell 1844) (Cephalopoda: Octopoteuthidae) from southern African waters

Reproductive features of the poorly known oceanic squid Octopoteuthis sicula are described and quantified to gain insight into the reproductive biology of the species. The data are based on 39 complete and partial specimens from southern African waters, collected between 1975 and 2005. The specimens ranged in mantle length from 38 mm to 290 mm and included juveniles and mature females and males. The species shows femalebiased sexual size dimorphism. Ovulation is asynchronous, indicating a repeated spawning strategy. Males transfer spermatophores presumably by using their long terminal organ. Spermatangia (discharged spermatophores) were found implanted in several parts of the body in both females and males, including in the anterior dorsal and ventral rugose, semi-gelatinous mantle tissue of maturing and mature females. This modified mantle tissue was only well developed in females. The morphologies of the spermatophore and the spermatangium of O. sicula are described. The spermatophoric reaction is reconstructed, using various stages of discharge, to provide insight into the process of intradermal implantation of spermatangia of this species. Keywords: Cephalopoda; implantation; mating; Octopoteuthis sicula; reproductive system; spawning; spermatangium; spermatophore; spermatophoric reaction; squidAfrican Journal of Marine Science 2008, 30(3): 603–61

Adaptation of an immunodot assay for multiple prey identification of squid paralarvae in field trials

An optimized method, using polyclonal antibodies in all immunoassay, for prey detection ill the diet of paralarvae of South African Loligo reyaudii is described. The study has increased the specificity of the antisera by determining the optimum antiserum dilutions and the detection limits of the antisera. Unfed laboratory-hatched paralarvae (negative control) were exposed to antisera and showed cross-reactions, with polychaete antiserum