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The Asian green mussel Perna viridis, was first detected in Tampa Bay, FL, in 1999 and quickly spread throughout the bay. The long-term population trend of P. viridis from 2002 to 2017 was assessed by monitoring settlement to collectors and bycatch of P. viridis in trawls in Tampa Bay. In addition, a suite of water-quality parameters and trends in predator abundance were modeled to evaluate the effects of these variables on P. viridis in the bay. Since 2002, settlement and bycatch of P. viridis in Tampa Bay has declined by 83% and 62%, respectively, in relation to nitrogen concentrations and productivity fluctuations limiting resource availability and energy acquisition in P. viridis. While Florida stone crab (Menippe mercenaria) landings, Atlantic blue crab (Callinectes sapidus) landings, and catch per unit effort of C. sapidus in fisheries independent monitoring trawls decreased throughout the study period, C. sapidus landings were the only biotic factor that was significantly related to P. viridis settlement. Temperature and salinity extremes, while not significant parameters in the models, likely negatively affected the distribution and persistence of P. viridis in the bay. Taken together, these findings suggest that conditions within Tampa Bay were not conducive to the large-scale dominance of P. viridis that was predicted when they were first introduced and they currently do not fit the definition of a problematic, invasive species. Conditions have been sufficient for this introduced species to remain established as a relatively minor constituent of the benthic community. [ABSTRACT FROM AUTHOR]

The green mussel Perna viridis (Linnaeus 1758), a native of the Indo-Pacific, has been introduced to the Atlantic basin and Caribbean Sea. It was reported first in Cienfuegos Bay, Cuba, in 2005. This species has proliferated quickly and now constitutes an economic as well as ecological problem, interfering with the operations of a local thermoelectric plant. The objectives of this study were to document the spatial and temporal variation in P. viridis density across Cienfuegos Bay and to examine the relationship between P. viridis density and water-quality patterns within the bay. The presence and relative abundance of P. viridis were surveyed qualitatively in Cienfuegos Bay in January 2011. Four sites were selected for additional investigation, and mussel density was estimated 6 times during 2011 and 2012. Temperature, salinity, and dissolved oxygen also were measured. We found that P. viridis density differed across Cienfuegos Bay both temporally and spatially, and that, although salinity may play a role in green mussel distribution and density, other factors were also important. The greatest densities of P. viridis were located near the city of Cienfuegos on the northeastern shore of the bay. The results of our systematic sampling also revealed dramatic temporal variation in the Cienfuegos Bay P. viridis population. During the 22-mo study, green mussel density at two of the sampling sites declined by an order of magnitude. There are several possible explanations for the dramatic decline in P. viridis density during the sampling period. Among them are mortality resulting from stressful environmental conditions and removal through harvest, both coupled with low recruitment rates. The decline of the population in the bay suggests that this species is not a candidate for a commercial fishery and that manual harvest may be an efficient means of eradication, if desired. [ABSTRACT FROM AUTHOR]

In July 1999, green mussels were seen for the first time at Tampa Electric Company's (TECO) Gannon Station Power Plant (Gulf of Mexico, Hillsborough Bay portion of Tampa Bay, western coast of Florida) during routine maintenance of the seawater intake system. The mussels were identified as Perna viridis (Linnaeus 1758) based on shell and anatomical characters. This identification has been confirmed by cytological analysis. Perna viridis had previously not been found in the United States or in the Gulf of Mexico. Perna viridis is a native species in the Indian and Pacific Oceans and was discovered in the Caribbean Sea in Trinidad in 1990 and in Jamaica in 1998. The populations are widespread locally and well established: the largest specimen collected was estimated to be 15 months of age. This is the second species of Perna introduced to the Gulf of Mexico, joining Perna perna (Linnaeus 1758). which was discovered in Texas in 1990. Since the initial discovery of Perna viridis ill Tampa Bay, range surveys have found it as far north as John's Pass in St. Petersburg, Pinellas County, Florida and as far south as Boca Grande, Charlotte County, Florida. [ABSTRACT FROM AUTHOR]

The green-lipped mussel Perna viridis is distributed widely in estuarine and coastal areas of the Indo-Pacific region and is regarded as a cultured mussel or by-product in aquaculture. However, in estuarine and coastal waters where salinity varies with freshwater input and rainfall during the wet season, hypoxia frequently occurs, especially when waters are highly eutrophic. The current study aimed to evaluate the effects of two key environmental factors in estuarine and coastal waters—dissolved oxygen (DO) and salinity—on growth and body composition of juvenile green-lipped mussels P. viridis. Parameters studied included shell length (SL), tissue dry weight (TDW), condition index (Cl), specific growth rate (shell length, SGRL; tissue dry weight, SGRW moisture content (MC), crude protein (CP), crude fat (CF), crude carbohydrate (CC), crude ash (CA), and energy content (EC). Mussels were cultured for 6 wk at 4 salinities (15, 20, 25, and 30) and 3 dissolved oxygen concentrations (1.5 ± 0.3, 3.0 ± 0.3, and 6.0 ± 0.3 mg O2/L) in a 4 X 3 factorial design. All growth parameters (SL, TDW, CI, SGRL, and SGRW,) decreased under reduced DO and salinities, but interactive effects between these 2 factors were statistically indistinguishable except for SGR~~. Higher percentages of CF and CP, and lower percentages of CC were obtained at reduced salinities and DO. When changes in biochemical content (weight per individual) were compared, both CP and CC content decreased significantly as salinity or DO decreased, whereas no pattern was observed for CF. EC (calories per gram) was not significantly different among DO treatments, but varied significantly with salinity. Total energy content (calories per individual), however, increased significantly with both DO and salinity, but the interaction between salinity and DO was statistically indistinguishable. [ABSTRACT FROM AUTHOR]

This work concerns the effects of cadmium exposure on the anaerobic and oxidative metabolism in tissues of the hypoxia-tolerant green mussel Perna viridis from Venezuelan coastal waters. The mussels were exposed to different Cd concentrations (0, 20, 40 and 60 µg/L Cd) for 7 days, and were subsequently exposed to anoxia. Prior to anoxia exposure, Cd concentration was determined in the digestive gland and adductor muscle. After 24 h of anoxia, the activities of pyruvate kinase (PK), phosphoenolpyruvate carboxykinase (PEPCK), and cytochrome c oxidase (CCO), and catalase (CAT) were measured in the digestive gland and adductor muscle from Cd-treated mussels. Also, effects of the Cd treatments on the median survival time (LT50) during anoxia were determined. The short-term Cd-exposed mussels augmented the metal uptake in the tested tissues in a dose-dependent manner, associated with a concomitant reduction in the ability to withstand anoxia. During normoxic and anoxic conditions, the Cd-exposed individuals displayed decreased levels of PK, PEPCK, and CCO in comparison with controls, with the change being most evident during anoxia. Conversely, an increase in CAT was observed in Cd-treated organisms. This effect was further potentiated during anoxia. The toxic action of Cd uptake on PK and PEPCK could reduce the tolerance of anoxia, because these are regulatory glycolytic enzymes in mussels. Moreover, the decreased CCO activity could limit the capacity to recuperate from anoxia. The enhanced CAT activity in Cd-exposed organisms may have been in response to H2O2 produced during oxidative stress, and was likely accentuated during anoxia. [ABSTRACT FROM AUTHOR]

We evaluated the capacity of metallothioneins (MT) in maintaining anaerobic metabolism in the green lipped mussel Perna viridis during experimentally induced oxidative stress. Mussels were exposed to 50 µg/L of cadmium during seven days, followed by recuperation in the sea during 35 days. Other groups of cadmium pre-exposed organisms and their respective controls were exposed to 200 and 500 mM of ferric iron/100 mM ascorbate to promote the formation of reactive oxygen species (ROS) by the Fenton reaction. Oxidative damage was evidenced by the malondialdehyde (MDA) production through thiobarbituric acid reactive substances (TBARS). The activities of the enzymes, hexokinase (HK), piruvate kinase (PK), and glucose-6-P dehydrogenase (G6PDH) in the digestive gland and the survival during anoxia were evaluated. Exposure of organisms to cadmium led to a significant bioaccumulation of this metal with concomitant high MT levels. Survival during prolonged periods of anoxia was reduced only in the iron/ascorbate exposed organisms, which exhibited an increase in MDA concentration; however, the cadmium-preexposed and control organisms showed similar resistance to anoxia. The iron! ascorbate-exposed organisms showed a decrease in the activities of H K in the cytosol and H K, PK, and G6PDH of the particulate fraction. In comparison with the control group, the cadmium pre-exposed/iron-exposed organisms did not show significant differences in lipid peroxidation. associated with elevated MT levels. In conclusion, the data obtained suggest that of the glycolytic enzymes, HK and PK and G6PDH are targets to the attack by ROS and that the MT can protect molecules against these effects. MT appears to protect against ROS induced injury, allowing maintenance of metabolic control by glycolytic enzymes that are important during anaerobic metabolism. [ABSTRACT FROM AUTHOR]

Histologic examination of the nonnative green mussel, Perna viridis, and the native scorched mussel, Brachidantes exustus, at three locations in Tampa Bay, Florida, indicated that cycles of gametogenesis and spawning were similar between species. Major spawning periods occurred in the spring (April) in conjunction with increasing water temperature and the fall (September to November) as the water temperature was declining. Over the summer, both species appeared to undergo varying levels of redevelopment, partial spawning and resorption of oocytes. Gametogenesis was limited over the winter. Differences between populations in levels of gametogenic activity and the timing of the fall spawn were most likely related to differences in salinity and available food at the three sites. A higher fecundity (caused by the faster growth rate and greater maximum size of P. viridis) may result in displacement of native bivalves in Tampa Bay, including B. exustus. [ABSTRACT FROM AUTHOR]

Since being accidentally introduced into Tampa Bay in the Gulf of Mexico in 1999, the green mussel (Perna viridis), a native to the Indo-Pacific region, has proliferated and dispersed southwards along peninsular Florida. During 2002 another introduction of P. viridis occurred on the northeast coast of Florida and larval dispersal has also carried the species northward in Atlantic coastal waters. In anticipation of their arrival in Georgia, a campaign was initiated to alert recreational and commercial water users to report all sightings. Observations of living and dead mussels trickled in during 2003 from all over coastal Georgia, confirming the presence of the mussel here for the first time and representing the expansion of the range of this invasive species to its most northerly location in the United States. [ABSTRACT FROM AUTHOR]

In 1999, the green mussel, Perna viridis, was first observed in Tampa Bay, Florida. This was the first reported occurrence of this Indo-Pacific marine bivalve in North America. The mussels found in Tampa Bay were confirmed to be P. viridis based on both morphological and genetic characteristics. Since the initial discovery, surveys in Tampa Bay and on the West coast of Florida have documented the growth, recruitment, and range expansion of P. viridis. From November 1999 to July 2000, the mean shell length of a Tampa Bay population increased from 49.0 mm to 94.1 mm, an increase of 97%. Populations of P. viridis are successfully reproducing in Tampa Bay. Recruitment was observed on sampling plates in May and continued through July 2000. The full extent of mussel colonization is not clear, but mussels were found outside Tampa Bay in St. Petersburg, Florida, south to Venice. Based on these studies it is evident that P. viridis has successfully invaded Tampa Bay and the west coast of Florida. The long-term impact of P. viridis on native communities off the west coast of Florida cannot be predicted at this time. [ABSTRACT FROM AUTHOR]

The tropical Asian green mussel, Periza viridis (Bivalvia: Mytilidae) is a recent invader in the Caribbean Basin, including the subtropical southeastern United States. In this study we examined the (1) range of P. viridis in the southeastern United States, (2) relative abundance of P. viridis across habitats and (3) density of P. viridis in Tampa Bay, FL. The invasion and spread of P. viridis in the southeastern United States was estimated by a combination of first-hand qualitative sampling and second-hand observations. There were apparently at least two discrete introductions, each followed by natural dispersal. The initial invasion was discovered in Tampa Bay in 1999, and was followed by rapid spread of P. viridis south as far as Marco Island, FL, but limited spread northward. In 2002, a second invasion occurred in northeast Florida. separated from the west Florida population by 650 km of coastline. On the east coast, P. viridis appeared to be distributed discontinuously between South Carolina and the Indian River Lagoon, FL by 2007. The literature concerning native distribution, habitat use and invasion history, and vectors of P. viridis is also reviewed. [ABSTRACT FROM AUTHOR]