Larval Atlantic Menhaden Research Articles

Vertical distribution of larval Atlantic menhaden (Brevoortia tyrannus) and Atlantic croaker (Micropogonias undulatus): Implications for vertical migratory behaviour and transport

AbstractUnderstanding the interactions among biological and physical processes is essential to determining how the environment affects transport and survival of fishes. We examined vertical distribution in larval Atlantic menhaden (Brevoortia tyrannus) and Atlantic croaker (Micropogonias undulatus) using 126 depth stratified tows in Delaware Bay, USA, during two cruises, in December 2007 and February 2008. Menhaden larvae were 16.8–24.6 and 20.5–26.2 mm standard length in December and February. Corresponding lengths for croaker were 9.3–17.9 and 8.6–19.6 mm. Using empirical observations, and statistically derived models, we explored larval concentration for both species as a function of location, depth, diel period, tidal period, size, and pairwise interactions. Menhaden concentration was best modeled as a function of station, cruise, and interactions between depth and size as well as between station and cruise. No significant differences in larval menhaden concentration were present among tidal and diel periods. Croaker concentration was best modeled as a function of size and interactions between station and diel period, depth and size, cruise and size. Despite tidal period not emerging as a significant model parameter, we observed larger croaker larvae during nighttime flood tides. Our statistical models are consistent with processes of up‐estuary transport for both species, suggesting larvae are increasingly affected by behavioral responses as larvae grow, exhibiting stronger patterns in vertical distribution. The results refine our understanding of the potential importance of size‐related differences in vertical distribution for larval transport in these species. Future research should examine the interactions among size‐specific vertical migratory capabilities, vertical distribution, transport, and retention.

Temperature and Somatic Growth Effects on Otolith Growth of Larval Atlantic Menhaden, <I>Brevoortia Tyrannus</I> (Actinopterygii: Clupeiformes: Clupeidae)

Background. If a link exists between somatic and otolith growth, otolith size and microstructure analysis can be a useful tool in studies of larval fish growth and condition—methods like growth back-calculation or marginal increment width analysis can be employed. Because significance of that link may vary among species and can be additionally modified by temperature, the aim of the present paper is to evaluate how sagittal otoliths of Atlantic menhaden responded to somatic growth and temperature. Materials and methods. Larval Atlantic menhaden, Brevoortia tyrannus (Latrobe, 1802) (age range: 20–120 days; length range: 14–35 mm SL), collected during 3 years were evaluated for length-at-age and groups of the shortest and longest-at-age individuals (8% of sampled population in each group) were used in the analyses. Similarly, otolith size-at-age estimated from sagittae length was evaluated and then compared with the earlier estimated growth indices of larvae. Results. Otolith growth rate (OGR) indicated growth differences among analysed larvae. Additionally, temperature effect on OGR independent of somatic growth was detected for larvae that were short-at-age (i.e., the slow growth group). For the fast grow group, temperature effect on OGR was insignificant. Conclusion. Back-calculation of growth from otoliths of larval and early juvenile Atlanticmenhaden is justified but less accurate estimates can be expected for the slowest growing individuals due to the independent temperature effect on otolith growth.

Fluctuating asymmetry in the otoliths of larval Atlantic menhaden Brevoortia tyrannus (Latrobe) – a condition indicator?

Fluctuating asymmetry (FA) was described for otolith length, width and area for two groups of larval and juvenile Atlantic menhaden Brevoortia tyrannus. The larvae and juveniles (age range: 20–120 days; standard length, LS, range: 14–35 mm) were separated into the two distinct groups a priori on the basis of their growth indices estimated from residuals of a LS‐at‐age model; slow growers had residuals <8% of the average size at age and fast growers had residuals >8%. Some indication supporting the fluctuating asymmetry methodology was found when unsigned normalized FA2 index was used for otolith area. That conclusion was not, however, supported by the other method used in this work, i.e. between‐group ANCOVA analysis of individual unsigned and not normalized FA1 indices plotted against trait size. These inconsistent results are most probably a consequence of error introduced during FA index normalization (accounting for trait size effect on absolute FA). Although it is concluded here that FA analysis of sagittal otoliths was not effective in describing differences in the natural variability of growth and condition of larval Atlantic menhaden, the possible species‐ and otolith type‐related differences should be considered in the future research on FA.

Juvenile atlantic menhaden ( Brevoortia tyrannus) in Delaware Bay, USA are the result of local and long-distance recruitment

We examined patterns of abundance, age, and spawning date distribution for juvenile Atlantic menhaden, Brevoortia tyrannus, collected during monthly sampling in Delaware Bay salt marshes during 1996 and 1997 in order to determine temporal patterns of recruitment and their spawning locations. Two distinct cohorts were present during both years of the study; the first cohort appeared in April–May and persisted throughout the summer, while the second cohort appeared in July but was only represented in subsequent collections during 1997. Back-calculated birth dates indicated that some fish had spawned during the fall (September and October) during both years, probably in the vicinity of Delaware Bay. However, the majority of individuals were spawned during winter months (primarily December and January) when water temperatures were too cold to permit local spawning. These winter-spawned individuals probably originated south of Cape Hatteras where winter water temperatures are warm enough (>16 °C) to allow spawning and larval development. These winter-spawned fish were an important but variable fraction of the fish surviving to the juvenile stage in Delaware Bay fish (92 and 73% during 1996 and 1997, respectively). The pattern of fall and winter-spawned juvenile Atlantic menhaden using Delaware Bay is consistent with an earlier study of larval Atlantic menhaden in another southern New Jersey estuary and thus suggests that contributions of spawning from both the Middle Atlantic States and south of Cape Hatteras may occur consistently for Atlantic menhaden and other species.

Condition of laboratory-reared and wild-caught larval Atlantic menhaden Brevoortia tyrannus as indicated by metabolic enzyme activities

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 175:51-66 (1998) - doi:10.3354/meps175051 Condition of laboratory-reared and wild-caught larval Atlantic menhaden Brevoortia tyrannus as indicated by metabolic enzyme activities Tristan J. Fiedler*, M. Elizabeth Clarke, Patrick J. Walsh** Division of Marine Biology and Fisheries, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, Florida 33149, USA *Present address: Graduate Program in Biochemistry, Cell and Molecular Biology, University of Miami School of Medicine, R-629, PO Box 016129, Miami, Florida 33101-6129, USA **E-mail: pwalsh@rsmas.miami.edu ABSTRACT: As part of the South Atlantic Bight Recruitment Experiment (SABRE), the condition of larval Atlantic menhaden Brevoortia tyrannus from Onslow Bay, North Carolina, USA, was determined. The activities of the metabolic enzyme lactate dehydrogenase (LDH) were assayed in larval Atlantic menhaden to determine nutritional condition of laboratory-reared and wild-caught larvae on cruises in 1992 to 1994. In laboratory calibrations, larvae whose first feeding was delayed had depressions in protein-specific LDH activities, and LDH activity appeared to scale with length. Wild larvae had LDH activities within the range of activities found in laboratory-reared larvae and were classified into 3 nutritional categories based on length and LDH activities. Fewer than 30% of larvae collected from the majority of stations were classified in superior condition. No differences were detected between larvae collected during the day and those collected at night. Significant decreases in condition were evident with increasing distance from the Gulf Stream Front. LDH activities indicated that a substantial percentage of wild-caught menhaden larvae were poorly nourished during the period examined. KEY WORDS: Larval menhaden · Lactate dehydrogenase · Nutritional condition · Onslow Bay Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 175. Publication date: December 17, 1998 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1998 Inter-Research.

Endogenous swimming rhythms of larval Atlantic menhaden, Brevoortia tyrannus Latrobe: Implications for vertical migration

Atlantic menhaden, Brevoortia tyrannus Latrobe, spawn on the continental shelf. Larvae are transported shoreward where they enter estuaries and metamorphose. Field studies suggest that while offshore, larvae may undergo nocturnal diel vertical migration (DVM), in which they are near the surface during the night and at depth during the day. The DVM pattern is more pronounced in estuaries but the timing of the nocturnal ascent may be related to tides. Larvae appear to swim in the water column during nocturnal rising tide and are less abundant at all other times. This migration pattern would result in up-estuary movement by selective tidal stream transport. The present study measured endogenous swimming rhythms of Atlantic menhaden larvae and related them to possible vertical migration patterns in offshore and estuarine areas. Larvae reared in the laboratory on a diel light:dark cycle were measured at three sizes (7–9 mm, 14–17 mm and 23–27 mm total length [TL]) as representative of larvae in offshore areas, while estuarine larvae (25–30 mm TL) were collected in the Newport River Estuary (N.C.). Swimming was monitored in a column under constant conditions in the laboratory with a time-lapse video system. In all cases, larvae had a similar circadian rhythm. The smallest laboratory reared larvae ascended into the upper portion of the column during the time of night and descended during the time of day. The other laboratory reared and field caught larvae had increased swimming activity during the time of night and reduced activity during the time of day. This circadian activity rhythm would contribute to the nocturnal DVM in offshore and estuarine areas. However, there was no evidence that larvae developed a tidal rhythm in activity that could contribute to selective tidal stream transport in estuaries.

Behavioural response of larval Atlantic menhaden to different rates of temperature change

Larval Atlantic menhaden Brevoortia tyrannus, spawned off North Carolina (U.S.A.) during the winter, undergo cross‐shelf transport from the western Gulf Stream edge to coastal bays and estuaries. Variation in water flow direction with depth provides larvae the opportunity to enhance shoreward transport, if they can regulate their depth behaviourally. Temperature, which normally decreases with depth on the continental shelf, is one possible cue for depth regulation. Laboratory‐reared larval menhaden of two different ages were exposed to varying relative rates of temperature increases and decreases, which were presented from both above and below the larvae. Temperature decreases from below caused an ascent response in both young and old larvae, but neither responded to this cue from above. The minimum (threshold) relative rates of decrease for initiating ascents were similar (7.9 × 10−2, 10.7 × 10−2° C min−1) for both age larvae as were the minimum absolute amounts of decrease that must occur before a response (0.1, 0.05°C). Young larvae did not respond to a temperature increase, while old larvae ascended regardless of whether the increase was presented from above or below. Threshold relative rates of increase were 8.59 × 10−2°C min−1 from below and 14.79 × 10−2° C min−1 from above. The threshold rates and range of larval speeds during vertical movements were used to calculate vertical temperature gradients that could be perceived. These values were compared to measured gradients in areas inhabited by menhaden larvae. On the continental shelf, detectable temperature gradients appear common for temperature decreases that would occur upon descending and temperature increases upon ascending. However, it is uncommon for larvae to encounter temperature increases upon descending that would initiate an ascent response. These results support the hypothesis that menhaden larvae are capable of using temperature gradients for depth regulation.

Behavioral response of larval Atlantic menhaden Brevoortia tyrannus (Latrobe) and spot Leiostomus xanthurus (Lacépède) to rates of salinity change

Larval Atlantic menhaden [ Brevoortia tyrannus (Latrobe)] and spot [ Leiostomus xanthurus) (Lacépède)] are transported from the western Gulf Stream edge to bays and estuaries of the southeastern United States. Direction of water flow on the continental shelf varies with depth, allowing the potential for enhancement of shoreward transport by behavioral depth regulation, possibly in response to vertical salinity gradients. Salinity profiles from the North and South Carolina continental shelf were analyzed to quantify the salinity gradients in the field. Behavioral response to salinity was investigated by exposing laboratory spawned and reared menhaden and spot larvae of different ages to rates of salinity change in an experimental apparatus in the laboratory. At each rate of salinity change tested, five replicate runs were recorded each with groups of 30 to 50 larvae. Both species and age groups showed a significant ascent response upon salinity increases. Rates of increase of 0.28 and 0.13 × 10 −1 ppt · min −1 with absolute salinity increases of 0.8 and 0.3 ppt were thresholds for response by young (4–13 days post-hatching) and old (2–4 wk post hatching) menhaden larvae, respectively. For spot, rates of increase of 1.15 and 0.85 × 10 −1 ppt · min −1 with absolute salinity increases of 1.4 and 2.0 ppt were thresholds for response by young and old larvae, respectively. Response to decreasing salinity was absent in both species, thus decreasing salinity with depth would not cause larvae to descend. In nature, salinity gradients of sufficient magnitude for depth regulation, and possibly facilitating cross-shelf transport appear common for menhaden, but not for spot.

Eulerian views of layered water currents, vertical distribution of some larval fishes, and inferred advective transport over the continental shelf off North Carolina, USA, in winter

ABSTRACTCurrents that effect the shoreward transport of the larvae of estuarine‐dependent fishes spawned in winter in Onslow Bay, North Carolina, USA, were driven by winds and pressure gradients, and influenced by the Gulf Stream. Aside from storms, winds over the continental shelf in Onslow Bay blew predominantly alongshore with velocities approaching 14 m s‐1 during February and March 1986, and January and February 1989. Water masses and currents observed at two current‐meter moorings, one at mid‐shelf and the other on the outer shelf, reflected the onshore (or offshore) advection of interior water in compensation for the offshore (or onshore) advection of wind‐driven surface water. Winds and currents reversed direction approximately every 4 to 6 days. The larvae of Atlantic menhaden, Brevoortia tyrannus, spot, Leiostomus xan‐thurus, and Atlantic croaker, Micropogonias undulatus, were most abundant in 17–19oC and 20–21oC water of the outer shelf and Gulf Stream fronts. There was little indication of diel vertical migration; larval Atlantic menhaden were most abundant in mid‐ and surface water, while spot and Atlantic croaker were most abundant in mid‐ and deep water. Given this distribution, the inferred advective transport of larvae was at times onshore, but at other times it was offshore. Within a spawning season, the prevalence of either reciprocation could determine the number of larvae that reach coastal inlets.

Age, Growth, and Size Distribution of Larval Atlantic Menhaden off North Carolina

Counts of growth increments on sagittal otoliths of larval Atlantic menhaden Brevoortia tyrannus spawned and reared in the laboratory showed that 1 increment/d was formed beginning 5 d after fertilization and that increment counts could be used to estimate larval age, A Gompertz growth equation described the relationship between age and standard length (SL) for 353 larvae collected off North Carolina in fall and winter, 1979–1980. Larvae grew from 3.4 mm SL at hatching to 25.2 mm SL at 100 d. Age of larvae varied inversely with capture distance from shore, Age distribution of larvae on the North Carolina continental shelf suggests that transport of larvae from offshore spawning sites to the estuary was biphasic. Transport was relatively rapid to within about 35 km of shore and relatively slow from there to shore, Mean age at estuarine recruitment increased from 40 to 80 d throughout the recruitment season, which may represent differences in transport rate.

Metabolic scaling, buoyancy, and growth in larval Atlantic menhaden, Brevoortia tyrannus

We measured growth of larval Atlantic menhaden, Brevoortia tyrannus in terms of mass, volume, and weight in water as well as the mass-specific activities of the metabolic enzymes citrate synthase, lactate dehydrogenase, and malate dehydrogenase. Weight in water, the force the fish must exert to maintain vertical position, increases by a factor of 18 in larvae growing from 10 to 15 mm. The weight increase coincides with the development of the larval swim bladder. The activities of all three enzymes per unit mass of fish tissue decline greatly over this time period, indicating that the fish does not further develop its aerobic and anaerobic metabolic capacity for swimming during this growth interval.

Storm-related variation in the growth rate of otoliths of larval Atlantic menhaden Brevoortia tyrannus: a time series analysis of biological and physical variables and implications for larva growth and mortality

Vertical mixing induced by storms is hypothesized to modify the spatial and temporal availability of food to fish larvae and thus influence their feeding and growth. We investigated the effects of storms on sagitta growth rates of 2 age classes (3 to 15 d and 16 to 50 d, post-hatching) of larval Atlantic menhaden Brevoortia tyrannus during winter 1986 in Onslow Bay, North Carolina, USA. We tested the null hypothesis that sagitta growth rate of 3 to 15 d and 16 to 50 d old larvae is independent of the timing and intensity of storms by using transfer functions to investigate relationships among daily time series of sagitta growth rate and meteorological and oceanographic variables. Variation in sagitta increment width was greatest during the first 1 to 2 wk after hatching. Reduction in sagitta growth rate coincided with storms and corroborated laboratory results that growth increments are formed daily and stressful events are manifest in sagitta microstructure. Age-related trends in sagitta growth rate were observed for both age classes and were removed from the analysis by a standardization procedure. Fluctuation in sagitta growth rate for 3 to 15 d old larvae was inversely crosscorrelated with time series of wind speed. Fluctuation in sagitta growth rate for 16 to 50 d old larvae was inversely cross-correlated with tune series of wind speed and heat flux The pattern of crosscorrelations for 3 to 15 d old larvae indicated an immediate response of sagitta growth rate to periods of strong winds while sagitta growth rate in 16 to 50 d old larvae lagged strong winds and heat fluxes by 2 to 5 d. Transfer function models incorporating wind speed and heat flux accounted for 40 to 54 % of sagitta growth rate variation. Reduction in larval Atlantic menhaden growth rate during early life is consistent with the critical period concept and may be related to dispersion and aggregation mechanisms coupled to wind-induced vertical mixing and its effect on food concentration and availability.

Estimates of Larval-Fish Abundance: Diurnal Variation and Influences of Sampling Gear and Towing Speed

Abstract The influence of net-towing speed on estimates of the abundance of larval Atlantic menhaden Brevoortia tyrannus, spot Leiostomus xanthurus, pinfish Lagodon rhomboides, and Atlantic croaker Micropogonias undulatus was studied in nearshore and estuarine areas of North Carolina. A modified Miller high-speed sampler was towed at speeds ranging from 2 to 12 m/second. In one series, catch increased monotonically with increasing tow speed up to 7 m/second; in a second series, catch increased with speed up to 8 m/second but decreased at higher speeds, possibly because larvae were extruded through the net or deflected by the pressure wave. In additional studies, a slowly towed (2 m/second) 20-cm bongo net was compared to the high-speed sampler during daylight; day and night samples from the high-speed sampler also were compared. These data imply that visual avoidance by larval fish biases estimates of both their abundance and their vertical distribution. The data from all three studies suggest the need to...

Occurrence and Abundance of Larval Atlantic Menhaden, Brevoortia tyrannus, at Two North Carolina Inlets with Notes on Associated Species

Abstract A comparison was made of relative indexes of abundance for Atlantic menhaden larvae entering two North Carolina inlets. Larvae entered the inlets from November through April 1966–67 and 1967–68, and were most abundant in March during both survey periods. Collections over 24 hours showed that larvae are more abundant at night than in the day and are more abundant in the slower tidal currents. As the larvae drift back and forth on the ebbing and flooding currents and feed on plankton, their condition factors (weight/length3) increase. The abundance of 23 other species of fish collected with the menhaden is also discussed.

Effects of Salinity and Temperature on Survival and Development of Larval Atlantic Menhaden,Brevoortia tyrannus

Effects of Salinity and Temperature on Survival and Development of Larval Atlantic Menhaden,<i>Brevoortia tyrannus</i>

The Effect of Minimum Temperature on the Survival of Larval Atlantic Menhaden, Brevoortia tyrannus

Transactions of the American Fisheries SocietyVolume 94, Issue 4 p. 409-412 Short Papers and Notes The Effect of Minimum Temperature on the Survival of Larval Atlantic Menhaden, Brevoortia tyrannus Robert M. Lewis, Robert M. Lewis Bureau of Commercial Fisheries, Biological Laboratory, Beaufort, North Carolina, USASearch for more papers by this author Robert M. Lewis, Robert M. Lewis Bureau of Commercial Fisheries, Biological Laboratory, Beaufort, North Carolina, USASearch for more papers by this author First published: October 1965 https://doi.org/10.1577/1548-8659(1965)94[409:TEOMTO]2.0.CO;2Citations: 18AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume94, Issue4October 1965Pages 409-412 RelatedInformation