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2. Chondracanthid copepod parasites of dories (Zeiformes: Zeidae) with the description of a new species of Chondracanthus from waters off northern Argentina
- Creator:
- Braicovich, Paola E., Lanfranchi, Ana L., Incorvaia, Inés S., and Timi, Juan T.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Copepoda, taxonomy, South America, zeids, marine fish, host range, and zoogeographical distribution
- Language:
- English
- Description:
- A new species of parasitic copepod, Chondracanthus hoi sp. n. (Copepoda: Chondracanthidae), is described based on specimens of both sexes collected from the buccal cavity and gill arches of the silvery john dory, Zenopsis conchifer (Lowe) (Zeiformes: Zeidae), from waters off northern Argentina (35-36°S, 53-54°W). Female of C. hoi differs from its congeners by the following combination of characters: presence of five pairs of trunk processes, antennule with four knobs tipped with small setae and absence of denticles on the terminal process of maxilla. Chondracanthids and zeiform fishes have been proposed as an example of co-speciation; this assumption is derived from a series of analyses based on incomplete records of both geographical distribution and host range of some parasite species, as well as misidentification of fish hosts. These inconsistences observed during our bibliographical analyses are also discussed.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
3. Genetic and morphological evidence reveals the existence of a new family, genus and species of Echinorhynchida (Acanthocephala)
- Creator:
- Braicovich, Paola E., Lanfranchi, Ana L., Farber, Marisa D., Marvaldi, Adriana E., Luque, José L., and Timi, Juan T.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Rhadinorhynchidae, Cavisomidae, Gymnorhadinorhynchidae fam. n., Gymnorhadinorhynchus gen. n., and marine fish
- Language:
- English
- Description:
- Gymnorhadinorhynchus gen. n. is proposed to accommodate its type species, G. decapteri sp. n., a parasite of the marine fish Decapterus punctatus (Cuvier), caught from the coastal waters of Brazil. Gymnorhadinorhynchus decapteri sp. n. was morphologically most similar to species of two echinorhynchid families, the Rhadinorhynchidae and the Cavisomidae, particularly in the structure of the proboscis and the absence of somatic spines, respectively. This combination of morphological features made it difficult to assign our specimen to an extant family of the Acanthocephala. Therefore, in order to clarify the systematic placement of G. decapteri, a molecular phylogenetic analysis was performed based on the SSU and LSU rDNA and the mitochondrial cox1 gene sequences obtained for the new taxon and other 26 acanthocephalan species. The results of parsimony and maximum likelihood analyses, using individual, combined and concatenated sequence data, consistently indicate that the specimens do not belong to any known family of the Echinorhynchida. Rather, G. decapteri represents a distinct lineage that is closely related to the Transvenidae, but distantly related to both the Rhadinorhynchidae and the Cavisomidae. Gymnorhadinorhynchidae fam. n. is therefore erected. This newly described family can be distinguished from other families of Echinorhynchida by the combination of the following morphological characters: a proboscis cylindrical with 10 rows of 22-26 hooks, dorsoventral differences in proboscis hooks, basal hooks forming a ring and being abruptly larger than anterior hooks, absence of trunk spines and presence of four tubular cement glands. This combination, in addition to several molecular autapomorphies, justifies the erection of a new genus, Gymnorhadinorhynchus gen. n., in order to accommodate this new species.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4. Seasonal stability in parasite assemblages of the Brazilian flathead, Percophis brasiliensis (Perciformes: Percophidae): predictable tools for stock identification
- Creator:
- Braicovich, Paola E. and Timi, Juan T.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- parasite communities, temporal stability, biological tags, fish populations, and south-west Atlantic
- Language:
- English
- Description:
- A comparison of the composition and structure of parasite communities of the Brazilian flathead, Percophis brasiliensis Quoy et Gaimard (Perciformes: Percophidae) among seasons during one year was carried out in the Argentine Sea. A total of 195 fish specimens were examined and 25 parasite species were found. Parasite communities in seasonal samples showed a high degree of homogeneity in taxonomic composition and infection levels. Similarity analysis showed that the seasonal stability within and between samples was constant in both the composition and community structure throughout the year. Parasites can, therefore, be considered predictable markers for fish stock identification, independently of the season of capture, at least on an annual scale.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public