ALBERT

Description: Cephalopod paralarvae and juveniles were sampled with light traps deployed at the surface and deeper in the southern NW Shelf and on Ningaloo Reef off Western Australia during two consecutive summers. One cross shelf transect (Exmouth) was sampled in the late spring and summers of 1997/1998 (summer 1) and 1998/1999 (summer 2), and a second cross shelf transect (Thevenard) and a longshore transect (Ningaloo) along the Ningaloo Reef were sampled in summer 2. Species captured in the order of abundance were octopods, Photololigo sp., Sepioteuthis lessoniana, and Sthenoteuthis oualaniensis. Most were captured in shallow traps except for Photololigo sp., which was common in both shallow and deep traps with larger animals found in deeper water. The presence of Idiosepius pygmaeus in deep water off Ningaloo Reef revealed the species to be eurytopic, inhabiting a wider range of habitats than previously known. Photololigo sp. and S. lessoniana were more abundant inshore, and octopods were especially abundant on mid-depth stations of the Exmouth transect, probably because of the turbulent mixing and increased productivity there. Fewer S. oualaniensis were caught during the first summer on the Ningaloo transect (n = 5) than during the second summer (n = 79).

Description: Paralarvae of the family Gonatidae were sampled in the Gulf of Alaska during spring 2001–2003. Taxonomic characters were determined to allow identification of the specimens to species. The dorsal head chromatophore pattern (DHCP) was the most robust character and allowed identification to species for the first time without requiring the removal and examination of the radula. Six different DHCPs were found among the six species in the study area. The 1140 specimens collected consisted of the following six species: Berryteuthis anonychus (759), Berryteuthis magister (71), Gonatopsis borealis (155), Gonatus kamtschaticus (1), Gonatus madokai (4) and Gonatus onyx (143). The specimens had a size range of 3.0–20.63 mm dorsal mantle length with the majority of specimens smaller than 10 mm. All species showed an increasing trend in abundance from the shelf (0–200 m) to the slope (200–1000 m) to the basin (〉1000 m) except G. onyx in 2001 and 2002. Wide variation in distribution and abundance was found for the four most abundant species; however, in general, B. anonychus was most abundant and widely distributed, followed by Gonatopis borealis, Gonatus onyx and B. magister.

Description: A new genus of octopus, Sasakiopus, is erected for the species S. salebrosus (Sasaki, 1920) n. comb. Sasakiopus salebrosus is redescribed from the holotype and from new material recently collected in the eastern Bering Sea. Molecular phylogenetic analysis of one nuclear and three mitochondrial genes revealed that the new genus is the sister taxon of a clade containing the genera Benthoctopus and Vulcanoctopus. The clade containing Sasakiopus, Benthoctopus and Vulcanoctopus is the sister group of Enteroctopus. The genus Bathypolypus falls outside this clade. Sasakiopus differs from Bathypolypus and Enteroctopus by the shape of its ligula (simple in Sasakiopus and Benthoctopus, laminate in Bathypolypus and elongate in Enteroctopus), from Enteroctopus by the absence of enlarged suckers in mature male animals and from Benthoctopus by its skin sculpture and ability to ink.

Description: Distribution, size and maturity patterns, and ontogenetic changes in morphological characters of the squid species Gonatus tinro and Gonatopsis okutanii were examined. The database includes information collected during research surveys to the Sea of Okhotsk and the adjacent Northwest Pacific Ocean from 1972 through 2005. Both species are distributed within the same areas beyond the shelf: G. tinro within a wide range of depths and an active vertical migrant, G. okutanii mostly demersal, characteristic of many adult gonatids. Seasonal changes in size and maturity of G. tinro and G. okutanii are congruent in many respects: G. tinro are usually small and young with hookless tentacle clubs, and squid identified as G. okutanii tend to be larger adults with truncated tentacles. The comparative morphology of the two species and the discovery of individuals bearing external features of both indicate that G. okutanii is an adult stage and G. tinro a young stage of the same species. It is concluded that G. okutanii is a junior synonym of G. tinro, which becomes the valid name by precedence.

Description: Species richness and abundance are two commonly measured parameters used to characterize invasion risk associated with transport vectors, especially those capable of transferring large species assemblages. Understanding the relationship between these two variables can further improve our ability to predict future invasions by identifying conditions where high-risk (i.e. species-rich or high abundance or both) and low-risk (i.e. species-poor and low abundance) introduction events are expected. While ballast water is one of the best characterized transport vectors of aquatic non-indigenous species, very few studies have assessed its magnitude at high latitudes. We assessed the arrival potential of zooplankton via ballast water in the Canadian Arctic by examining species richness, total abundance, and the relationship between the two parameters for zooplankton in ships from Europe destined for the Arctic, in comparison with the same parameters for ships bound for Atlantic Canada and the Great Lakes. In addition, we examined whether species richness and/or total abundance were influenced by temperature change and/or ballast water age for each shipping route. We found that species richness and total abundance for Arctic and Great Lakes ships were significantly lower than those for Atlantic ships. Differences in species richness and total abundance for ships utilizing different shipping routes were mostly related to ballast water age. A significant species richness–total abundance relationship for Arctic and Great Lakes ships suggests that these parameters decreased proportionately as ballast water aged. In contrast, the absence of such a relationship for Atlantic ships suggests that decreases in total abundance were accompanied by little to no reduction in species richness. Collectively, our results indicate that the arrival potential of zooplankton in ballast water of Arctic ships may be lower than or similar to that of Atlantic and Great Lakes ships, respectively.

Description: Matching was developed in the 1960s to match such entities as residents and hospitals, colleges and students, or employers and employees. This approach is based on “preference lists,” whereby each participant ranks potential partners according to his/her preferences and tries to match with the highest-ranking partner available. Here, we discuss the implications of matching for the study of mate choice and speciation. Matching differs from classic approaches in several respects, most notably because under this theoretical framework, the formation of mating pairs is context-dependant (i.e., it depends on the configuration of pairings in the entire population), because the stability of mating pairs is considered explicitly, and because mate choice is mutual. The use of matching to study mate choice and speciation is not merely a theoretical curiosity; its application can generate counter-intuitive predictions and lead to conclusions that differ fundamentally from classic theories about sexual selection and speciation. For example, it predicts that when mate choice is mutual and the stability of mating pairs is critical for successful reproduction, sympatric speciation is a robust evolutionary outcome. Yet the application of matching to the study of mate choice and speciation has been largely dominated by theoretical studies. We present the hamlets, a group of brightly colored Caribbean coral reef fishes in the genus Hypoplectrus (Serranidae), as a particularly apt system to test empirically specific predictions generated by the application of matching to mate choice and speciation.

Description: We propose that the exploitation of the bioactive properties of secondary metabolites (SMs) by animals can provide a “treatment” against various challenges that perturb homeostasis in animals. The unified theoretical framework for the exploitation of SMs by animals is based on a synthesis of research from a wide range of fields and although it is focused on providing generalized predictions for herbivores that exploit SMs of plants, predictions can be applied to understand the exploitation of SMs by many animals. In this review, we argue that the probability of SM exploitation is determined by the relative difference between the cost of a homeostatic challenge and the toxicity of the SM and we provide various predictions that can be made when considering behavior under a homeostatic perspective. The notion that animals experience and respond to costly challenges by exploiting therapeutic SMs provides a relatively novel perspective to explain foraging behavior in herbivores, specifically, and behavior of animals in general. We provide evidence that animals can exploit the biological activity of SMs to mitigate the costs of infection by parasites, enhance reproduction, moderate thermoregulation, avoid predation, and increase alertness. We stress that a better understanding of animal behavior requires that ecologists look beyond their biases that SMs elicit punishment and consider a broader view of avoidance or selection of SMs relative to the homeostatic state. Finally, we explain how understanding exploitation of SMs by animals could be applied to advance practices of animal management and lead to discovery of new drugs.

Description: Analysis of the demographic structure of Calanus species in the North Atlantic presents particular difficulties due to the overlapping spatial distributions of four main congeneric species (Calanus finmarchicus, Calanus helgolandicus, Calanus glacialis and Calanus hyperboreus). These species have similar morphologies, making microscopic discrimination only possible between some of the species at late copepodite or adult stages. However, molecular techniques now offer the possibility of screening significant numbers of specimens and unambiguously identifying them to species, regardless of developmental stage. Unfortunately, the processing rate of specimens by molecular methods is still too low to offer a realistic alternative to microscopy for analysis of samples from large field surveys. Here, we outline and test an approach involving the use of molecular methodology in conjunction with conventional microscopy to assess the species assignment of developmental stage abundances of Calanus congeners. Our study has highlighted many important methodological issues. First, it cannot be assumed that the species composition is homogeneous across the development stages; applying proportional species composition of adults to morphologically undistinguishable earlier development stages can result in error. The second important conclusion is that prosome length may be a highly unreliable discriminator of C. finmarchicus and C. glacialis.