The status and importance of cephalopod systematics in southern Africa

A checklist of southern African cephalopods published in 1974 listed 94 species for the region 20–45°S, 10–40°E. Just 23 years later the number of known species has doubled to an estimated 195, represented in theSouth African Museum collection by 4 252 accessioned lots (15 434 specimens, excluding many paralarvae). In 1995, cephalopods constituted the sixth most valuable fisheries resource worldwide (after shrimps and tunas). Only one subspecies, Loligo vulgaris reynaudii, is targeted in South Africa at present, but it is important commercially because of the high prices it commands internationally. A number of other species constitute alternate resources of potential commercial interest, including at least 12 sepiids, 7 loliginids, 6 ommastrephids and 9 octopods. Cephalopods are also important in the trophic relations of marine fish, birds and mammals. Knowledge of the southern African cephalopod fauna is important not only for regional biodiversity studies but also from a wider perspective. The region is strategically placed between the Atlantic, Indian and Southern oceans and the faunal composition is complex. The southern African cephalopods include about 20–30% of the known world cephalopod species. Resolution of taxonomic problems in the southern African context goes a long way towards global resolution, particularly among the oceanic species. The size and complexity of the South African Museum’scephalopod collection prompted the holding of a systematics workshop to produce a guide to southern African cephalopods. This paper provided a basis for that Biodiversity Workshop. A provisional checklist for the region is provided, species constituting a potential resource for either artisanal or larger fisheries are identified and unresolved problems in the systematics (including an undescribed genus and at least 12, but probably more than 20, new species) are indicated

Cephalopods in the diet of sperm whales caught commercially off Durban, South Africa

A collection from stomach contents of 30 sperm whales Physeter catodon comprised a total of 46 cephalopods belonging to six families. Nine species were identified, including Ommastrephes bartramii, which is recorded for the first time in the diet of sperm whales caught off South Africa, and Todarodes filippovae, which has only previously been identified from whale stomachs to genus. Sexed individuals of all species were female and most were gravid. Comparisons are made with a much larger collection of beaks from the same source and the species identity of some of these can now be established or confirmed

Fecundity and reproductive strategies in deep-sea incirrate octopuses (Cephalopoda: Octopoda).

Coleoid cephalopods show flexibility in their reproductive strategies or mode of spawning, which can range from simultaneous terminal spawning over a short period at the end of the animal’s life to continuous spawning over a long period of the animal’s life. Although a simultaneous terminal spawning strategy is typical of shallow water temperate octopuses, it is not known whether deep-sea octopods would have the same reproductive strategy. The reproductive strategies and fecundity were investigated in nine species of deep-sea incirrate octopuses: Bathypolypus arcticus, Bathypolypus bairdii, Bathypolypus ergasticus, Bathypolypus sponsalis, Bathypolypus valdiviae, Benthoctopus levis, Benthoctopus normani, Benthoctopus sp., and Graneledone verrucosa (total n = 85). Egg-length frequency graphs and multivariate analysis (principal components analysis) suggest that B. sponsalis has a synchronous ovulation pattern and therefore a simultaneous terminal spawning strategy. Although a simultaneous terminal spawning strategy is most likely for B. levis and B. normani, the egg-length frequency graphs and multivariate analysis also suggest a greater variation in egg-lengths which could lead to spawning over an extended period

The deep‑water squid Octopoteuthis sicula Rüppell, 1844 (Cephalopoda: Octopoteuthidae) as the single species of the genus occurring in the Mediterranean Sea

The genus Octopoteuthis includes squids inhabiting meso- and bathypelagic waters worldwide. Of the seven presently named species distributed in the world’s oceans, only Octopoteuthis sicula has been reported for certain in the Mediterranean Sea to date. However, mixed and confusing descriptions of the systematic characters useful for identifying the species occur in the literature. Similarly, molecular analysis results available for the genus are contradictory and inconsistent. The research herein was undertaken firstly to clarify the systematic status of the genus in the Mediterranean Sea and confirm the presence of a single species, namely O. sicula. Additional goals were the assessment of the validity of systematic characters to identify the species and the analysis of beak morphology to provide useful tools in prey–predator relationship studies. Octopoteuthis specimens from various areas of the Mediterranean Sea and the Atlantic and Pacific oceans were compared, and the analysis of traditional morphological characters was combined with molecular genetics and the study of beaks. Molecular genetics and beak morphology results support the existence of a single species in the Mediterranean Sea. Additional evidence would suggest that this species is also distributed in the north-eastern Atlantic. The morphological characters reported in the literature to identify O. sicula did not identify Mediterranean specimens, with the exception of the two tail photophores. All information collected supports the need for a reconsideration of morphological characters used to identify Octopoteuthis species.Versión del editor2,011