Age and growth of two sharpnose shark species (Rhizoprionodon lalandii and R. porosus) in subtropical waters of the south-western Atlantic

A taxonomic revision of the Nystiellidae from Brazil, including samples from the Rio Grande Rise, South Atlantic, was performed based on shell morphology. Five genera and 17 species were recognized. For the richest genus,Eccliseogyra, the three species previously recorded from Brazil were revised:E. brasiliensisandE. maracatu, previously known only from their respective type series, were re-examined. Newly available material ofE. maracatuexpanded the known geographic range of this species to off south-east Brazil.Eccliseogyra nitidais now recorded from north-eastern to south-eastern Brazil, as well as from the Rio Grande Rise. Three species ofEccliseogyraare newly recorded from the South Atlantic:E. monnioti, previously known from the north-eastern Atlantic, occurs off eastern Brazil and on the Rio Grande Rise; its protoconch is described for the first time, confirming its family allocation.Eccliseogyra pyrrhiasoccurs off eastern Brazil and on the Rio Grande Rise, andE. folinioff eastern Brazil. The genusIphitusis newly recorded from the South Atlantic.Iphitus robertsiwas found off northern Brazil, although the shells show some differences from the type material, with less-pronounced spiral keels. Additional new finds showed thatIphitus cancellatusranges from eastern Brazil to the Rio Grande Rise, and Iphitusnotiossp. nov. is restricted to the Rio Grande Rise.Narrimania, previously recorded from Brazil based on dubious records, is confirmed, including the only two living species described for the genus:N. azelotes, previously only known from the type locality in Florida, andN. concinna, previously known from the Mediterranean. A third species,Narrimania raquelaesp. nov. is described from eastern Brazil, diagnosed by its numerous and thinner cancellate sculpture. To the three species ofOpaliopsispreviously known from Brazil, a fourth species,O. arnaldoisp. nov., is added from eastern Brazil, and diagnosed by its very thin spiral sculpture, absence of a varix, and thinner microscopic parallel axial striae.Papuliscala nordestina, originally described from north-east Brazil, is recorded off eastern Brazil and synonymized withP. elongata, a species previously known only from the North Atlantic.

Download Full-text

Distribution, history, and taxonomy of the Thais clade (Gastropoda: Muricidae) in the Neogene of tropical America

Journal of Paleontology ◽

10.1017/s0022336000039731 ◽

2001 ◽

Vol 75 (3) ◽

pp. 697-705 ◽

Cited By ~ 11

Author(s):

Geerat J. Vermeij

Keyword(s):

New Species ◽

South Atlantic ◽

Eastern Pacific ◽

Caribbean Region ◽

Large Species ◽

The South ◽

Western Atlantic ◽

Extinction Rates ◽

Tropical America ◽

The Caribbean

The earliest known members of the Thais clade of rapanine muricid neogastropods comprise four species from the Cantaure Formation (early Miocene: Burdigalian) of Venezuela; three of these species are new. Neorapana rotundata Gibson-Smith et al., 1997, is most closely related to the Recent Pacific Mexican N. tuberculata (Sowerby, 1835), and represents the only known Atlantic occurrence of the genus. Thais brevicula new species is closest to T. callaoensis (Gray, 1828) from the Recent of northern Peru and the Galápagos. A review of the genus Thais indicates that the typical members of this group occur in the South Atlantic, West Africa, and eastern Pacific, but not in the Recent fauna of the southern Caribbean. Stramonita bifida new species is a large species related to the Recent S. haemastoma floridana (Conrad, 1837), which occurs throughout the Caribbean. A review of American species of Stramonita indicates that the taxon S. biserialis (de Blainville, 1832) from the Recent fauna of the eastern Pacific, and the taxon S. h. haemastoma (Linnaeus, 1767), may each be composed of more than one species despite the teleplanic dispersal of their larvae. Stramonita semiplicata new species is closely related to the Recent S. bicarinata (de Blainville, 1832) from the South Atlantic, and represents a lineage that occurred in the Caribbean region until at least the late Miocene. It may have given rise to the eastern Pacific genus Acanthais. The higher diversity and greater antipredatory specialization of eastern Pacific as compared to western Atlantic members of the Thais clade may have resulted from higher post-Miocene rates of speciation and lower extinction rates in the eastern Pacific.

Download Full-text

Age and growth of the shortfin mako (Isurus oxyrinchus) in the south-eastern Pacific off Chile

Marine and Freshwater Research ◽

10.1071/mf08125 ◽

2009 ◽

Vol 60 (5) ◽

pp. 394 ◽

Cited By ~ 16

Author(s):

Francisco Cerna ◽

Roberto Licandeo

Keyword(s):

Growth Parameters ◽

Eastern Pacific ◽

Age And Growth ◽

The South ◽

Age Classes ◽

Vertebral Centra ◽

South Eastern ◽

Isurus Oxyrinchus ◽

Shortfin Mako ◽

Longline Fisheries

The shortfin mako, Isurus oxyrinchus, is a large pelagic shark with a widespread global distribution. However, very little is known about most aspects of this species for the south-eastern Pacific. In the present paper, the age and growth parameters of the shortfin mako, caught by Chilean swordfish longline fisheries from 2004 to 2005, are reported. Ages were estimated by counting band-pairs from sections of vertebral centra from 547 individuals, ranging from 76 to 330 cm in total length (TL). Trends in the proportion of opaque edges for all ages combined and grouped into ages 0–6 and 7–26 years indicated that they are formed during summer and showed that annually, one band-pair is formed in the vertebrae of shortfin makos. Modal-progression analysis was used to verify the first three age classes (ages 0–2 years). For both sexes, the oldest estimated age was 25+ years. Von Bertalanffy growth parameters were estimated at L∞ = 325.29 cm TL, K = 0.076 year–1 and t0 = –3.18 years for females and L∞ = 296.60 cm TL, K = 0.087 year–1 and t0 = –3.58 years for males. The results indicated that this species is highly vulnerable to exploitation and, thus, urgent conservation measures are required.

Download Full-text

Activity, habitat utilization, feeding behaviour, and diet of the sand moray Gymnothorax ocellatus (Anguilliformes, Muraenidae) in the south western Atlantic

Biota Neotropica ◽

10.1590/s1676-06032003000100003 ◽

2003 ◽

Vol 3 (1) ◽

pp. 1-7 ◽

Cited By ~ 15

Author(s):

Flávia Borges Santos ◽

Ricardo M. C. Castro

Keyword(s):

Feeding Behaviour ◽

Habitat Utilization ◽

South Atlantic ◽

Muddy Sand ◽

The South ◽

Western Atlantic ◽

Sense Of Smell ◽

Sand Bottom

Activity, habitat utilization, feeding behaviour, and diet of the sand moray Gymnothorax ocellatus (Anguilliformes, Muraenidae) in the South western Atlantic. The sand moray Gymnothorax ocellatus is a nocturnal predator from the western South Atlantic that actively forages on the bottom, preying mostly on crustaceans (mainly shrimps and crabs) and ray-finned fishes, which are located primarily by the sense of smell. The individuals stay stationary during the day, almost always being hidden in individual tunnels dug by animals other than the morays in the muddy sand bottom.

Download Full-text

Age and growth estimation of bigeye tuna, Thunnus obesus (Teleostei: Scombridae) in the southwestern Atlantic

Neotropical Ichthyology ◽

10.1590/s1679-62252012000100014 ◽

2012 ◽

Vol 10 (1) ◽

pp. 148-158 ◽

Cited By ~ 7

Author(s):

Paulo Duarte-Neto ◽

Fábio M. Higa ◽

Rosangela P. Lessa

Keyword(s):

Fork Length ◽

Age And Growth ◽

Data Uncertainty ◽

Bigeye Tuna ◽

Western Atlantic ◽

Thunnus Obesus ◽

Marginal Increment ◽

Back Calculation ◽

Growth Estimation ◽

Averaged Model

The purpose of the current study was to supply the first information on age and growth for Thunnus obesus caught in the equatorial south-western Atlantic using dorsal spines, an approach that has been successfully employed for ageing tuna species. The study was conducted using a multi-model inference based on information theory for back-calculated and observed length-at-age data. Uncertainty associated with the parameter estimation was verified and results were compared to other accounts on the species, considering both the statistical and methodological contexts. Samples were collected in Natal city (Rio Grande do Norte State, Brazil) from February 1999 to January 2000, of tuna vessels and from surveys, aimed at providing information on the Brazilian Exclusive Economic Zone (EEZ) in the area around São Pedro and São Paulo Archipelago. Validation using marginal increment indicated that one ring is deposited per year. Mean length-at-age ranged of 54.3 to 177.5 cm (fork length) for ages 1 to 9 years. Von Bertalanffy, Richards, and Gompertz models were considered suitable for the bigeye tuna. Hence, the model-averaged asymptotic length ¯L∞ was estimated. The averaged model generated in the present study by back-calculation was considered appropriate for describing the growth of T. obesus.

Download Full-text

Potential use of anal fin spines for assessing age and growth of longbill spearfish, Tetrapturus pfluegeri, in the western Atlantic Ocean

Bulletin of Marine Science ◽

10.5343/bms.2015.1043 ◽

2016 ◽

Vol 92 (4) ◽

pp. 385-398 ◽

Cited By ~ 2

Author(s):

Maite Pons ◽

Freddy Arocha ◽

Andrés Domingo ◽

David J Die ◽

Alejandro Brazeiro ◽

...

Keyword(s):

Atlantic Ocean ◽

Age And Growth ◽

Western Atlantic ◽

Western Atlantic Ocean ◽

Potential Use ◽

Fin Spines

Download Full-text

Gracilaria phuquocensis sp. nov., a new flattened Gracilaria species (Gracilariales, Rhodophyta), previously recognized as G. mammillaris, from the southern coast of Vietnam

10.26686/wgtn.12509957.v1 ◽

2020 ◽

Author(s):

HN Le ◽

N Muangmai ◽

S Kheauthong ◽

Z Sun ◽

Giuseppe Zuccarello

Keyword(s):

New Species ◽

South China Sea ◽

South China ◽

Taxonomic Status ◽

Molecular Data ◽

The South China Sea ◽

The South ◽

Western Atlantic ◽

China Sea ◽

Coast Of Vietnam

© 2019 Japanese Society of Phycology Flattened Gracilaria species are widely distributed along the coasts of the South China Sea with more than 20 species recorded. Within the South China Sea, Gracilaria mammillaris has only been reported from Vietnam, but this species is likely restricted to the western Atlantic. This study aimed to reevaluate the taxonomic status of Vietnamese specimens of ‘G. mammillaris’ using combined morphological and molecular data. Our data clearly indicated that Vietnamese specimens were morphologically and genetically distinct from authentic G. mammillaris from the western Atlantic, and also other described flat Gracilaria species. We, therefore, propose that specimens from Vietnam originally identified as G. mammillaris be designated as a new species, Gracilaria phuquocensis sp. nov. Morphologically, G. phuquocensis can be distinguished from other flat Gracilaria species by its small thallus size, narrower blades, many medullary layers, abundant basal nutritive filaments within mature cystocarps, and tetrasporangial nemathecium. Our rbcL sequence analyses showed that the new species was sister to Gracilaria rhodymenioides from Thailand, and these two species formed a clade with cylindrical Gracilaria species. Our study contributes to clarification of the taxonomic status of misidentified specimens attributed to the flattened Gracilaria species in the South China Sea.

Download Full-text