uero, J. (2014). Molecular and morphometric systematics of Diapterus (Perciformes, Gerreidae). -Zoologica Scripta, 43, 338-350. The fish belonging to Gerreidae are common representatives of the coastal ichthyofauna of the tropics and subtropics of the world. The genus Diapterus has a neotropical distribution and currently includes four species: two in the Atlantic Ocean [Irish mojarra D. auratus Ranzani 1842 and rhombic mojarra D. rhombeus (Cuvier 1829)] and two in the Pacific Ocean [short-beaked mojarra D. brevirostris (Sauvage 1879) and golden mojarra D. aureolus (Jordan & Gilbert 1882)]. This genus has uncertain taxonomy based on the remarkable and dissimilar morphology of D. aureolus. We evaluated the taxonomy and phylogeny of Diapterus with statistical (canonical discriminant analysis) and phylogenetic analyses (maximum parsimony, maximum likelihood and Bayesian inference) of geometric morphometric data (relative warps) and molecular data (12Sr RNA, 16Sr RNA, COI and RAG1 sequences). Our results indicate that the genus Diapterus as we currently conceive it is a polyphyletic group: [(Gerres cinereus -Eucinostomus spp. (D. aureolus -(Eugerres spp. (D. auratus -(D. brevirostris -D. rhombeus)))))]. Therefore, a taxonomic rearrangement is needed. To preserve the monophyly of the group, our proposal is to remove D. aureolus and place it in a new monotypic genus. A neotype is designated for D. aureolus as well as an artificial identification key for the genera and the species treated in this article.Our concept of a species is necessarily shaped by our understanding of the characters by which it attains objective and testable status in taxonomic research, [however] there is a disturbing trend to ignore deep thought about individual characters and to treat species as if they existed to be recognized by DNA barcodes rather than critically tested as evolutionary hypotheses. Those who misuse taxonomic information can answer for their own sins.(Valdecasas et al.

Summary Stock discrimination in fishes is important for fisheries management. Morphometric analysis has been a viable approach when different structures (overall body, otoliths, and scales) are used. However, in cases where a single source of information may already differentiate among stocks, different conclusions may be obtained when using different sources of information. These have to be considered because they could lead to different management plans. Using geometric morphometrics, data was analyzed regarding the body and otolith shape of the Pacific sardine Sardinops sagax Jenyns, 1842 collected off the west coast of Baja California Peninsula, Mexico. Results confirm seasonal differences in body shape and otolith shape in stocks previously associated with sea surface temperature. Although both measures resulted in compatible conclusions, the shape of the body discriminated groups more appropriately; the data indicate that differential resolution could be thus obtained, depending on the source of the data. If possible, the application of more than one source of information is suggested in comparable cases because this would detect the extent of stock isolation with greater certainty.

Studies focusing on the specific identification of the taxonomic cast within the genus Opisthonema are scarce and contradictory, in spite of this species commercial importance and of the potential ecological impact that fisheries may have on the pelagic ecosystem. In this study, the specific composition of thread herrings Opisthonema (O. bulleri, O. medirastre, and O. libertate) in the southeastern region of the Gulf of California was identified using meristic characters, morphometric data, and mtDNA sequences. In this paper we supported the hypothesis that the commercial catch comprises three evolutionary entities with meristic and morphometric differences. The results were based on the number of ceratobranchial gill rakers, the presence of spicules on the gill rakers, the form of insertion of the gill rakers base onto the ceratobranchial segment, the geometric morphometrics of body shape, and the genetic distances from a fragment of Cytochrome Oxidase Subunit I gene (COI) of mtDNA. Specimens of Pacific thread herring were obtained from landings of the small pelagic fleet at Mazatlan, Sinaloa during 2011-2012. Taxonomic categories were assigned to 1060 individuals according to the measurement of meristic characters. A total of 228 thread herrings O. bulleri, (n = 76), O. medirastre (n = 76), and O. libertate (n = 76) were used in the morphometric analysis, and 25 specimens (O. bulleri n = 8, O. medirastre n = 7, and O. libertate n = 10) were used for genetic comparisons. The morphometric results showed differences among the three groups that had been previously identified using meristic characters, giving support to the existence of three discrete morphotypes. The percentage of sequence divergence of the COI gene supports the existence of three clades. Genetic distances were considerably lower within each clade than between clades. The results of this study provide sufficient evidence for the existence of three Pacific thread herring species in the southern Gulf of California.U.S.

No abstract

In operations research, there are methodological tools included in decision theory that can help decision‐makers understand and systematize the decision‐making process. Decisions can be classified either as mono‐criterial, when only one criterion or goal is considered to evaluate its performance or multicriterial, which takes into account the interaction between two or more goals or criteria that can be in conflict. Natural resource management and finance are some important examples where the implementation of this type of tools has benefited the decision‐making process because they allow a number of criteria or objectives to be weighted in a transparent manner to assist when one or more decision‐makers are involved. Despite this, its application was not common in aquaculture; however, in recent years, efforts have increased exponentially. This work seeks to identify opportunity areas for development of new aquaculture‐related research through the implementation of multicriterial decision‐making methods (MCDM). To achieve this, a comprehensive bibliometric analysis was performed to detect MCDM applications that have been implemented in aquaculture industry (24 documents that were grouped into eight applications). Later, this information was complemented through the analysis of selected applications in natural resources management, specifically in fisheries, animal husbandry and agriculture. We propose 23 research topics relevant to the aquaculture industry that can be addressed by the methodologies in MCDM.