Ancient DNA Identification of Giant Snakehead (Channa micropeltes) Remains from the Market Street Chinatown and Some Implications for the Nineteenth-Century Pacific World Fish Trade

2021 ◽  
pp. 1-17
Author(s):  
J. Ryan Kennedy ◽  
Brittany Bingham ◽  
Mary Faith Flores ◽  
Brian M. Kemp

This study presents the results of ancient DNA analyses of eight snakehead (Channa sp.) bones from the Market Street Chinatown, a nineteenth-century Chinese diaspora archaeological site in San Jose, California. The sequences of a short stretch of the mitochondrial DNA identify the Market Street Chinatown snakeheads as Giant Snakehead (Channa micropeltes), a species native to Southeast Asia. These results provide the first archaeological evidence of the nineteenth-century trade of Asian freshwater fishes to North America, and they reveal that preserved fish products from throughout the Pacific World were readily distributed across the Chinese diaspora. We place our findings within the broader context of nineteenth-century Chinese migration to show how the common Chinese small shareholding business model and access to trade connections facilitated by Chinese-operated import/export firms known as jinshanzhuang allowed Chinese fishers to be successful across the Pacific World. Finally, we suggest avenues for future study by comparing Chinese migration-based, flexible fishing strategies using generalist methods with the highly specialized collection and trade of species like Atlantic Cod (Gadus morhua) in the North Atlantic.

2007 ◽  
Vol 64 (2) ◽  
pp. 304-313 ◽  
Author(s):  
Jan-Jaap Poos ◽  
Adriaan D Rijnsdorp

A temporarily closed area established to protect spawning Atlantic cod (Gadus morhua) in the North Sea allowed us to study the response of the Dutch beam trawl fleet exploiting common sole (Solea solea) and plaice (Pleuronectes platessa). A number of vessels left the North Sea 1 month earlier than the normal seasonal pattern. The vessels that continued fishing in the North Sea were concentrated in the remaining open areas. In the first week after the closure, the catch rate decreased by 14%, coinciding with an increase in crowding of 28%. Area specialisation affected the response of individual vessels because vessels without prior experience in the open areas showed a larger decline in catch rate compared with vessels that previously fished in these open areas and were more likely to stop fishing during the closed period. The decrease in catch rate in response to the increase in competitor density allowed us to estimate the strength of the interference competition.


2006 ◽  
Vol 80 (2) ◽  
pp. 193-197 ◽  
Author(s):  
R.A. Khan ◽  
C.V. Chandra

AbstractA study was conducted in 2000 and 2003, following the collapse of the commercial fishery in 1990, to compare metazoan parasites of Atlantic cod Gadus morhua, captured off coastal Labrador, with samples taken in 1980 and 1986. Fish were captured by otter trawl offshore in the North Atlantic Fish Organisation subarea 2J. Parasites were removed from the digestive tract, stained, identified and compared between the different groups. Both the prevalence and mean abundance of trematodes, larval nematodes and E. gadi were significantly lower in fish taken in 2000 and 2003 than in 1980. While mean values of trematodes and nematodes declined in 1986, those of Echinorhynchus gadi remained unchanged in 1986 and 1990. Four-year-old cod sampled in 1990 harboured significantly fewer E. gadi than older age groups. The most commonly occurring trematodes included Podocotylereflexa, Lepidapedon elongatum, Derogenes varicus and Hemiurus levinseni while the larval nematode, Anisakis sp. was predominant. Comparison of offshore samples taken in 2000 and 2003 with others taken in previous years suggests an overall decline of parasites coincident with a change in climatic conditions, the absence of a major food source, namely capelin Mallotus villosus, of cod and ultimately the decline of the Labrador population.


2018 ◽  
Vol 76 (2) ◽  
pp. 418-429 ◽  
Author(s):  
Henrik Svedäng ◽  
Julia M I Barth ◽  
Anders Svenson ◽  
Patrik Jonsson ◽  
Sissel Jentoft ◽  
...  

Abstract Dramatic and persistent reductions in Atlantic cod (Gadus morhua) are common in many coastal areas. While offshore cod stocks still were abundant and productive, the Swedish west coast showed signs of diminishing adult cod abundance at the beginning of the 1980s, where the local cod component was considered to be extirpated. To survey the present cod spawning activity and stock composition, we initiated egg trawling over two consecutive years (203 hauls in total) in combination with population genetic analyses (425 individually genotyped eggs). Here, we provide evidence of cod spawning at the Swedish Skagerrak coast, suggesting recolonization or that local cod has recovered from a nearly depleted state. Early stage eggs were found inside fjords too far to have been transported by oceanic drift from offshore spawning areas. The cod eggs were genetically similar in early to late life-stages and cluster mainly with the local adult cod, indicating that eggs and adults belong to the same genetic unit. The cod eggs were genetically differentiated from adult North Sea cod, and, to a lesser degree, also from the Kattegat and Öresund cod, i.e. indicating a possible recovery of local coastal stock. The patterns of the genetic structure in the inshore areas are, however, difficult to fully disentangle, as Atlantic cod in the North Sea-Skagerrak area seem to be a mixture of co-existing forms: local cod completing their entire life cycle in fjords and sheltered areas, and oceanic populations showing homing behaviours. The egg abundances are considerably lower compared with what is found in similar studies along the Norwegian Skagerrak coast. Nevertheless, the discovery of locally spawning cod along the Swedish west coast—although at low biomasses—is an encouraging finding that highlights the needs for endurance in protective measures and of detailed surveys to secure intraspecific biodiversity and ecosystem services.


Author(s):  
David Righton ◽  
Victoria Anne Quayle ◽  
Stuart Hetherington ◽  
Gary Burt

The sub-structure of Atlantic cod (Gadus morhua) stocks in the North Sea has important consequences for fisheries management as the Common Fisheries Policy moves towards a more regional approach. We investigated the movements, distribution and behaviour of cod in the southern North Sea (ICES IVc) and English Channel (ICES VIId) by re-analysing historic data from conventional tagging experiments, and by conducting new experiments with electronic tags. Cod tagged and released in IVc showed a northwards shift in distribution during the feeding season consistent with a homing migration away from spawning grounds along the coasts of the UK and the Netherlands. In contrast, cod tagged and released in VIId did not exhibit a consistent pattern of seasonal movement. Many cod released in VIId were subsequently recaptured close to their release position, although some moved out of the Channel and into the southern North Sea. Overlap between the recapture areas of cod released in the different management areas was no more than 25% in either the spawning or feeding season. Behavioural data from electronic tags suggest that cod in IVc make use of tidal streams to migrate northwards and eastwards in spring, whereas selective tidal stream transport was rarely exhibited by cod tagged and released in VIId. Overall, the evidence suggests that there are behavioural differences between cod in IVc and VIId that limit the mixing of cod from these two areas during the feeding and spawning seasons.


1988 ◽  
Vol 8 (3) ◽  
pp. 209-226 ◽  
Author(s):  
Alfonso Rojo

A sample of fifty-eight fish vertebrae from an archaeological site (Gooseberry Point, Campobello Island, N.B. Canada), has been identified as belonging to Atlantic cod ( Gadus morhua). From their morphometric study, it was possible to conclude the original size of the fish, their age, the seasonality of the campsite and the minimum number of individuals represented by the sample. The ages estimated from reading the vertebral rings varied from five to ten years. Some showed the growth of the “summer” in which they were caught, but many didn't have the growth-of-the-year suggesting a winter fishing activity. These estimates, along with the calculated live total length (from 523–961 mm) and the total weight (from 1,126–7,522 g) indicate that the fish utilized in the site were of a large size. This study used a number of methods to calculate MNIs which resulted in variance ranging from two to thirteen individuals.


Oceanologia ◽  
2014 ◽  
Vol 56 (1) ◽  
pp. 159-163
Author(s):  
Agnieszka Rybczyk ◽  
Przemysław Czerniejewski ◽  
Joanna Rokicka-Praxmajer

1999 ◽  
Vol 77 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Steven M Carr ◽  
David S Kivlichan ◽  
Pierre Pepin ◽  
Dorothy C Crutcher

Phylogenetic relationships among 14 species of gadid fishes were investigated with portions of two mitochondrial DNA (mtDNA) genes, a 401 base pair (bp) segment of the cytochrome b gene, and a 495 bp segment of the cytochrome oxidase I gene. The molecular data indicate that the three species of gadids endemic to the Pacific Basin represent simultaneous invasions by separate phylogenetic lineages. The Alaskan or walleye pollock (Theragra chalcogramma) is about as closely related to the Atlantic cod (Gadus morhua) as is the Pacific cod (Gadus macrocephalus), which suggests that T. chalcogramma and G. macrocephalus represent separate invasions of the Pacific Basin. The Pacific tomcod (Microgadus proximus) is more closely related to the Barents Sea navaga (Eleginus navaga) than to the congeneric Atlantic tomcod (Microgadus tomcod), which suggests that the Pacific species is derived from the Eleginus lineage and that Eleginus should be synonymized with Microgadus. Molecular divergences between each of the three endemic Pacific species and their respective closest relatives are similar and consistent with contemporaneous speciation events following the reopening of the Bering Strait ca. 3.0-3.5 million years BP. In contrast, the Greenland cod (Gadus ogac) and the Pacific cod have essentially identical mtDNA sequences; differences between them are less than those found within G. morhua. The Greenland cod appears to represent a contemporary northward and eastward range extension of the Pacific cod, and should be synonymized with it as G. macrocephalus.


2017 ◽  
Vol 74 (6) ◽  
pp. 1561-1573 ◽  
Author(s):  
Kate McQueen ◽  
C. Tara Marshall

AbstractWarming temperatures caused by climate change have the potential to impact spawning phenology of temperate marine fish as some species have temperature-dependent gonadal development. Inter-annual variation in the timing of Atlantic cod (Gadus morhua) spawning in the northern North Sea, central North Sea and Irish Sea was estimated by calculating an annual peak roe month (PRM) from records of roe landings spanning the last three decades. A trend towards earlier PRM was found in all three regions, with estimates of shifts in PRM ranging from 0.9 to 2.4 weeks per decade. Temperatures experienced by cod during early vitellogenesis correlated negatively with PRM, suggesting that rising sea temperatures have contributed to a shift in spawning phenology. A concurrent reduction in the mean size of spawning females excluded the possibility that earlier spawning was due to a shift in size structure towards larger individuals, as large cod spawn earlier than smaller-sized individuals in the North Sea. Further research into the effects of climate change on the phenology of different trophic levels within the North Sea ecosystem should be undertaken to determine whether climate change-induced shifts in spawning phenology will result in a temporal mismatch between cod larvae and their planktonic prey.


2014 ◽  
Vol 59 (2) ◽  
Author(s):  
Foojan Mehrdana ◽  
Qusay Bahlool ◽  
Alf Skovgaard ◽  
Jesper Kuhn ◽  
Per Kania ◽  
...  

AbstractA parasitological investigation was performed on a total of 5380 Atlantic cod larvae, post-larvae and small juveniles sampled from the North Sea during a period of five years. The copepod Caligus elongatus (Von Nordmann, 1832) and the nematode Hysterothylacium aduncum (Rudolphi, 1802) were found at a relatively high prevalence of infection (4.6% and 5.2%, respectively). The infection by both parasites showed annual and spatial variability. C. elongatus showed a higher prevalence in 1992 compared to the following years, whereas the prevalence of H. aduncum increased from 1992 to 2001.We observed a relation between parasite distribution and parameters such as latitude and water depth. Adult digeneans (Lecithaster gibbosus and Derogenes varicus) and larval cestodes were also found with lower infection rates. Since changes of infection levels coincided with increasing North Sea water temperature in the studied period, it is hypothesized that temperature may affect parasite population levels. However, it is likely that other environmental factors may contribute to the observed variations. Absence of infection intensities higher than one nematode per fish in small larvae and post-larvae suggests that host survival may be affected by a high infection pressure. The relatively high levels of infection in the younger stages of cod, and the annual/spatial variability of these infections should be considered in the understanding of the early life dynamics of the species.


Sign in / Sign up

Export Citation Format

Share Document