Early Life History of Fishes in the San Francisco Estuary and Watershed

2004 ◽  
Keyword(s):  
Life History ◽  
San Francisco ◽  
Striped Bass ◽  
Early Life ◽  
Early Life History ◽  
San Francisco Estuary ◽  
Delta Smelt ◽  
History Of ◽  
Acanthogobius Flavimanus ◽  
Longfin Smelt

<em>Abstract.</em>—We analyzed data on spring and summertime larval and juvenile fish distribution and abundance in the upper San Francisco Estuary (SFE), California between 1995 and 2001. The upper SFE includes the tidal freshwater areas of the Sacramento–San Joaquin Delta downstream to the euryhaline environment of San Pablo Bay. The sampling period included years with a variety of outflow conditions. Fifty taxa were collected using a larval tow net. Two common native species, delta smelt <em>Hypomesus transpacificus </em>and longfin smelt <em>Spirinchus thaleichthys</em>, and four common alien taxa, striped bass <em>Morone saxatilis</em>, threadfin shad <em>Dorosoma petenense</em>, gobies of the genus <em>Tridentiger</em>, and yellowfin goby <em>Acanthogobius flavimanus</em>, were selected for detailed analysis. Outflow conditions had a strong influence on the geographic distribution of most of the species, but distribution with respect to the 2 psu isohaline (X2) was not affected. The distribution patterns of delta smelt, longfin smelt, and striped bass were consistent with larvae moving from upstream freshwater spawning areas to downstream estuarine rearing areas. There were no obvious relationships of outflow with annual abundance indices. Our results support the idea of using X2 as an organizing principle in understanding the ecology of larval fishes in the upper SFE. Additional years of sampling will likely lead to additional insights into the early life history of upper SFE fishes.

Early Life History of Fishes in the San Francisco Estuary and Watershed

2004 ◽  
Keyword(s):  
San Francisco ◽  
Striped Bass ◽  
Vertical Migration ◽  
Early Life ◽  
Life Histories ◽  
Early Life History ◽  
Small Surface ◽  
Delta Smelt ◽  
Larval Fishes ◽  
History Of

<em>Abstract.</em>—The goal of this study was to determine if the vertical distribution of larval delta smelt <em>Hypomesus transpacificus </em>and striped bass <em>Morone saxatilis </em>was affected by tidal stage and diel period. Delta smelt and striped bass have similar early life histories in that their larvae drift downstream from freshwater spawning habitats to brackish water rearing habitats. Little is known on whether the larvae undergo a vertical migration as they move downstream. Conical plankton nets were used to collect larval fishes from the surface, middle, and bottom sections of the main channels of the Sacramento and San Joaquin rivers. Samples were collected over six paired day–night cruises. Approximately 45,000 fish were collected; 82% were striped bass and 2% were delta smelt. More delta smelt were caught at night than during the day, and more at middle depth than surface or bottom. Very few striped bass were found at surface during day; most were caught at middle depth. Both species were fairly dispersed throughout the water column at night. Although striped bass larvae appear to undergo a small surface to middepth migration, this study indicates that larval delta smelt and striped bass do not undergo a mass diel or tidal vertical migration as they drift down the Sacramento and San Joaquin rivers.

Early Life History of Fishes in the San Francisco Estuary and Watershed

2004 ◽  
Keyword(s):  
Growth Rate ◽  
San Francisco ◽  
Striped Bass ◽  
Growth Rates ◽  
Early Life History ◽  
San Francisco Estuary ◽  
Annual Growth ◽  
Factors Affecting ◽  
Juvenile Abundance ◽  
History Of

<em>Abstract.</em>—We investigated factors affecting growth of larval striped bass <em>Morone saxatilis </em>in the San Francisco Estuary from 1984 to 1993. We estimated ages and growth rates of larval striped bass from daily otolith increments. Mean annual growth rates of 6–14 mm standard length striped bass varied from 0.13 to 0.27mm/d, the lowest rate occurring in 1989 and the highest in 1992. The 1989 growth rate was significantly lower than all other years, and growth rates for 1992 and 1993 were significantly higher than all other years, but did not differ from one another. Differences in annual growth rates apparently were due mainly to differences in mean annual prey densities because growth rate increased as prey density increased. Compared to both laboratory measured growth rates and growth rates of field-caught Chesapeake Bay larvae, growth rates from the San Francisco Estuary appeared to be high for the food available, indicating that larvae can grow at relatively high rates even at low prey densities. Correlation analyses did not support density-dependent control of growth rates. Growth rate was not significantly related to mean annual conductivity, water temperature, mortality rates, or the juvenile abundance index, but was significantly and positively correlated with densities of 1-mm length-groups of 9–14-mm striped bass.

Early Life History of Fishes in the San Francisco Estuary and Watershed

2004 ◽  
Keyword(s):  
Life History ◽  
San Francisco ◽  
Early Life ◽  
Larval Fish ◽  
Early Life History ◽  
San Francisco Estuary ◽  
Pacific Herring ◽  
Body Depth ◽  
Frequency Distributions ◽  
Vertical Distributions

<em>Abstract.</em>—Pacific herring <em>Clupea pallasi </em>is a commercially and ecologically important fish with a sizable stock that spawns and spends its early life history in the San Francisco Estuary (SFE). Yet very little is known about the basic ecology of larval Pacific herring in the SFE. We undertook a 3-year field study (1999–2002), focused on winter and spring collections in two regions of the SFE (the Central and San Pablo bays), to address three objectives: (1) determine seasonal abundance patterns of larval Pacific herring in the two bays, (2) examine the diet of larval Pacific herring, and (3) evaluate the condition of larval Pacific herring in the two bays. Pacific herring were a conspicuous component of the winter larval fish assemblage in both the San Pablo and Central bays, comprising a maximum of 22.5% and 5.5% of total abundance, respectively. Larval Pacific herring abundance peaked in February or March of each year, reaching a maximum density of 2.53/m<sup>3 </sup>(San Pablo) and 0.52/m<sup>3 </sup>(Central Bay). Length frequency distributions suggested that at least 2–3 cohorts were produced each year, with some evidence that larvae were slightly larger in San Pablo Bay. Larval Pacific herring fed on a broad range of prey types, including tintinnids, copepodids, copepod nauplii, diatoms, and gastropod veligers. The unusually high proportion of tintinnids in the diet (87% by number in March 2001) suggests an important protozoan–metazoan linkage. Condition of larvae was assessed by analyses of covariance of a “growth sensitive” variable (i.e., body weight, anal body depth, or pectoral body depth) regressed against a “growth insensitive” variable (i.e., standard length). These results showed marked differences between the bays: in Central Bay, early (small) larvae exhibited better condition, but within San Pablo Bay, larvae exhibited a greater rate of improved condition with increasing age (size). This suggests the possibility of important differences in the Central and San Pablo bays as larval Pacific herring nursery grounds. Several areas of future research on the ecology of larval Pacific herring in SFE are recommended (e.g., coupling between horizontal and vertical distributions and advective flow fields, predation, and feeding dynamics on protozoan versus metazoan prey).

Characterizing the early life history of an imperiled freshwater mussel (Ptychobranchus jonesi) with host-fish determination and fecundity estimation

2017 ◽  
Vol 36 (2) ◽  
pp. 338-350 ◽  
Author(s):  
John M. McLeod ◽  
Howard L. Jelks ◽  
Sandra Pursifull ◽  
Nathan A. Johnson
Keyword(s):  
Life History ◽  
Early Life ◽  
Freshwater Mussel ◽  
Early Life History ◽  
Host Fish ◽  
History Of

Early Life History of Spiny Lobster

Crustaceana ◽  
1994 ◽  
Vol 66 (3) ◽  
pp. 271-294 ◽  
Author(s):  
Bruce F. Phillips ◽  
John D. Booth
Keyword(s):  
Life History ◽  
Early Life ◽  
Spiny Lobster ◽  
Early Life History ◽  
History Of
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