Barred Sand Bass Research Articles

Feeding habits of Paralabrax nebulifer (Serranidae) during reproductive and non-reproductive seasons in an adjacent area to Magdalena Bay, Baja California Sur, Mexico

The barred sand bass Paralabrax nebulifer is a commercially important fish off the west coast of Baja California Sur. To assess the diet of this species and variations as a function of sex and reproductive condition, 60 specimens were captured using traps during seven seasonal sampling trips from August 2016 to August 2018 in an adjacent area to Magdalena Bay, Baja California Sur, Mexico. The stomach contents of 50 specimens were obtained (23 males and 27 females). Sex was diagnosed by direct observation of the gonads. Based on the gonadosomatic index, hepatosomatic index, and histological analyses, the reproductive season of the barred sand bass was corroborated for August 2016, April, August, and September 2017, and August 2018, and the non-reproductive season was corroborated for November 2016 and March 2018. The Index of Relative Importance (IRI) was used to classify the main diet components, which comprised three fish species, seven crustacean species, and one mollusk species. According to the IRI, the South American pilchard Sardinops sagax and the red pelagic crab Pleuroncodes planipes were the prey that contributed the most (55%) to the barred sand bass diet. The ANOSIM showed that there were significant differences in the amount and type of prey consumed by sex; the SIMPER analysis revealed that the species contributing the most to differences between the sexes were S. sagax (16.58%), Euphylax dovii (15.95%), Stenocionops ovata (12%), and P. planipes (11.82%) for females. There were significant differences in the amount and type of prey consumed between types of reproductive season; the species contributing the most to differences between seasons were Anchoa spp. (27.76%), and P. planipes for non-reproductive season (22.67%), and S. sagax (11.08%) for reproductive season. The feeding strategy of the barred sand bass was that of a specialist carnivorous predator that fed mainly on the fish Sardinops sagax during the reproductive season, which supply the dietary nutritional requirements of the lipids HUFA (arachidonic acid, 20:4n-6; eicosapentaenoic acid, 20:5n-3; docosahexaenoic acid, 22:6n-3), nutrients required to achieve reproductive success.

Early indicators of MPA effects are detected by stereo-video

Resource managers often outline discrete goals when implementing marine protected areas (MPAs), such as increases in organism abundance, biomass, or body size, to evaluate MPA success and thus inform future management decisions. Understanding which biological indicators are most sensitive to protection is essential for adaptive management, and while density is a commonly used metric to monitor MPAs, previous work has pointed to a lack of reliability of this metric to effectively evaluate MPAs, particularly during initial stages of protection. To determine which biological indicators of MPA success were evident 5 yr after protection began, we examined the differences in populations inside vs. outside MPAs for 3 fishes targeted by anglers—kelp bass Paralabrax clathratus, barred sand bass P. nebulifer, and California sheephead Semicossyphus pulcher—and 4 non-targeted species. We used stereo-video to determine the average body size, biomass, and density of each species in 7 MPAs in Southern California that were paired with nearby non-MPA sites. Responses of targeted species were detectable after 5 yr of protection in some MPAs. In most but not all MPAs, individuals were larger compared to outside MPAs for kelp bass and California sheephead. Biomass and density of targeted species appeared to be less sensitive to MPA effects. As expected, non-targeted species did not show evidence of MPA effects. Similar to past studies, our findings indicate that the choice of response variable and species studied may influence the perceived efficacy of MPAs, and we emphasize that increases in length may be a particularly sensitive indicator of effective protection.

Feasibility of hydroacoustic surveys of spawning aggregations for monitoring Barred Sand Bass populations off southern California

Feasibility of hydroacoustic surveys of spawning aggregations for monitoring Barred Sand Bass populations off southern California

Space use and inferred spawning activity of three exploited gamefish species on a large artificial reef

AbstractIntense fishing pressure has led to changes in species composition, demography and the over‐exploitation of many coastal fishes. To restore populations, artificial reefs (ARs) are used with the assumption that new habitat will increase fish productivity. Kelp bass (Paralabrax clathratus), barred sand bass (P. nebulifer) and California sheephead (Semicossyphus pulcher) are three important recreational gamefish species in southern California. Home ranging behaviour, space use and spawning‐related activity of these three species were quantified on a large AR. Kelp bass used the largest amount of area, but space use was similar among species. While no spawning behaviour could be determined for sheephead, kelp bass exhibited two different activity patterns during spawning months and barred sand bass migrated (indicative of spawning). Results of this study indicate that this large AR is providing suitable habitat for these species, and spawning‐related activity could be a sign that this AR is meeting essential life history demands.

Comparing video and visual survey techniques for Barred Sand Bass in rocky reef ecotone habitats

Comparing video and visual survey techniques for Barred Sand Bass in rocky reef ecotone habitats

Participatory management in a small-scale coastal fishery—Punta Abreojos, Pacific coast of Baja California Sur, Mexico

We describe the structure and historic landings of the Punta Abreojos fishing cooperative (Baja California Sur, Mexico) for the period between 2001 and 2015 to understand the dynamics of an economically and ecologically successful coastal fishing community according to catches and the direct income of fishers. A total of 21 commercial species were classified into three major groups: cultural resources, target resources and complementary resources. The most important resource in terms of total biomass was Paralabrax nebulifer (58.4%), followed by Panulirus interruptus and P. inflatus (13.6%). Seriola lalandi, Atractoscion nobilis, Caulolatilus princeps, Paralichtys californicus and P. woolmani made up minor proportions of the total biomass contributing 7.0%, 5.7%, 3.4% and 3.2% respectively. Haliotis fulgens and H. corrugata represented just 1.1% of the total biomass caught. Lobsters were the most profitable source of direct income for fisherman (77.5%), followed by the green and pink abalone (10.4%), barred sand bass (5.6%), white seabass (2.7%), California and speckled flounder (1.2%), yellowtail (1%) and whitefish (0.4%). The rest of the catch was composed of six species of finfish that represented 4.1% of the total catch biomass and 0.4% of the revenues from fishing.This work provides a first clear base-line description of the fisheries in Punta Abreojos which implements a management program that aims to ensure the wellbeing of the fishers and the fishery. The cooperative has been successful in maintaining catch at levels considered optimal to sustain revenues and continued annual landings. A management and cooperative structure that allows for adaptive change whilst maintaining revenues of the fishers is testament to the stewardship of the community and the participatory management upon which the community is built. For this reason, Punta Abreojos should be considered an example of a successful small-scale fishing cooperative that other, less successful fishing groups, can learn from.

Impacts of recently implemented recreational fisheries regulations on the Commercial Passenger Fishing Vessel fishery for Paralabrax sp. in California

The California Commercial Passenger Fishing Vessel (CPFV) fleet is unique in scale of operation, extensive fishing history, and economic impacts. The basses (Paralabrax sp.), which represent a principal target for the CPFV fleet, recently gained more stringent size limits and bag limits. The goal of this study was to conduct a survey of CPFV captains to assess perceptions regarding the status of two Paralabrax species, as well as the impacts of the new regulations. Catch and effort estimates were also obtained using CPFV logbook data to compare captains’ perceptions with actual changes in the fishery. The captains agreed that both species are vital to recreational fishing, and that the Barred Sand Bass stock is less healthy than Kelp Bass. Catch and effort analyses were consistent with this perception, with more dramatic declines in CPUE exhibited by Barred Sand Bass. The most experienced captains perceived the status of each species to be in a less healthy state than the less experienced captains, suggesting that shifting baselines are occurring. Most of the captains thought the increased minimum size limits had the greatest short-term impact on the fishing experience. The CPFV logbook data summaries support this assertion, but Kelp Bass CPUE showed a trend reversal. In contrast, Barred Sand Bass CPUE has precipitously declined, and spawning aggregations have been absent since 2013. The agreement between captains’ perceptions and logbook analyses strengthens the overall findings, and suggests captains are a valuable resource for informing fisheries management, especially in future studies with data-limited stocks.

Vulnerability of spawning aggregations of a coastal marine fish to a small-scale fishery

For marine fishes that form spawning aggregations, vulnerability to aggregation fishing is influenced by interactions between the spatio-temporal patterns of spawning and aspects of the fishery that determine fishing effort, catch, and catch rate in relation to spawning. We investigated the spatio-temporal dynamics of spawning and fishing for the barred sand bass, Paralabrax nebulifer, in Punta Abreojos, Mexico from 2010 to 2012 as a means to assess its vulnerability to aggregation fishing by the local commercial fishery. Monthly, spatial patterns in gonadal development in collected females indicated that adults formed spawning aggregations at two sites in Punta Abreojos during July and August. Monthly patterns in the spatial distribution of fishing matched the spawning behavior of P. nebulifer, with effort and catch concentrated at spawning aggregation sites during those months. However, fishing effort, catch, and catch-per-unit effort did not increase during the spawning season, and fishing activities associated with the spawning season comprised only a small percentage of the total annual effort (22%) and catch (17%). Therefore, while the population of P. nebulifer at Punta Abreojos should be vulnerable to aggregation fishing due to the spatio-temporal dynamics of its spawning aggregations, vulnerability is greatly reduced, because fishing activities are not disproportionately focused on spawning aggregations and fishing methods are not optimized to maximize harvest from the aggregations. Differences between our results and previous studies on aggregation fisheries for P. nebulifer in California, USA, reinforce the importance of assessing factors influencing vulnerability to aggregation fishing at regional scales for prioritizing management efforts.

EFFECTIVENESS OF THE ANESTHETIC AQUI-S® 20E IN MARINE FINFISH AND ELASMOBRANCHS.

Immersion anesthetics are used in hatchery settings by veterinarians, field biologists, and laboratory researchers to aid in handling finfish for medical procedures, research purposes, and moderating perceived stress responses. The only Food and Drug Administration- (FDA) approved anesthetic for food fish, tricaine methanesulfonate, requires a 21-d withdrawal period prior to harvest. Ten percent eugenol (AQUI-S® 20E) has been gaining momentum for FDA approval because of its 0-d withdrawal time if fish are not of harvestable size within 72 h of exposure. We performed two trials to determine appropriate anesthetic doses for two cultured marine finfish: Atractoscion nobilis (white seabass, WSB) and Seriola lalandi (California yellowtail, YT). Fish were held in a treated water bath for 10 min or until opercular beat rate slowed to a rate of <2 beats/min. Based on these results, we conducted a field trial with wild Paralabrax maculatofasciatus (spotted bay bass), Paralabrax nebulifer (barred sand bass), Paralichthys californicus (California halibut), Triakis semifasciata (leopard shark), and Mustelus californicus (grey smooth-hound) at a single dosing regime, with animals held 5-10 min in anesthetic baths. Anesthetic dosing of 35-55 mg L(-1) provided relatively fast induction and good anesthetic maintenance in cultured and wild finfish. Anesthetic induction times were comparable among S. lalandi and A. nobilis at 35-mg L(-1) to 75-mg L(-1) doses, but recovery times were variable. Mortality rates of 20-90% were observed at higher doses (75 mg L(-1) and 100 mg L(-1), A. nobilis; 55 mg L(-1) and 75 mg L(-1), S. lalandi). The apparent increase in sensitivity of S. lalandi may have been associated with nutritional stress in the fish tested. There were no differences in time to anesthesia or recovery among wild finfish species tested at a single dose. Anesthetic induction, maintenance, and recovery were less predictable in the elasmobranch species tested and additional trials are needed to determine optimal dosing.

Patterns of home ranging, site fidelity, and seasonal spawning migration of barred sand bass caught within the Palos Verdes Shelf Superfund Site

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 539:255-269 (2015) - DOI: https://doi.org/10.3354/meps11482 Patterns of home ranging, site fidelity, and seasonal spawning migration of barred sand bass caught within the Palos Verdes Shelf Superfund Site Garry N. Teesdale*, Barrett W. Wolfe, Christopher G. Lowe Department of Biological Sciences, California State University, Long Beach, 1250 Bellflower Blvd, Long Beach, California 90840, USA *Corresponding author: gnteesdale@gmail.com ABSTRACT: Barred sand bass Paralabrax nebulifer (Family: Serranidae; BSB) are among the most popular recreational game fishes in southern California and an important food fish. Patterns of residency and habitat use are critical for determining the potential for BSB to be impacted by point source anthropogenic contaminants prevalent in the densely populated coastal environment near Los Angeles, California. Home ranging behavior, degree of site fidelity, residency, habitat selection, and seasonal spawning migration of BSB were observed over 27 mo using a large, continuous coverage, fine-scale acoustic telemetry array (~20 km2). The 55 tagged individuals used small core areas (mean ± SD = 2682 ± 2005 m2 over 329 ± 227 d) and showed high affinity for the rock/sand ecotone at a depth of 20 to 30 m. Overall weekly residency to the array was 70 ± 25% of tagged fish present from the first tag date through the end of the study, with lower residency during the summer spawning season (June to August). Individuals leaving the array emigrated in a southeasterly direction 98% of the time, and 100% of the BSB detections outside the array occurred to the southeast of the Palos Verdes Shelf Superfund Site (PVSSS; 26.4 ± 0.8 km). BSB of legal size (>360 mm TL) exhibit high long-term site fidelity to small areas within the PVSSS and make seasonal migrations to spawning aggregations beyond the boundaries of the ‘do not consume’ zone defined by the Office of Environmental Health Hazard Assessment in 2009. KEY WORDS: Barred sand bass · Paralabrax · Serranidae · Home range · Site fidelity · Spawning migration · Palos Verdes · Superfund · DDT · Acoustic telemetry · VPS Full text in pdf format PreviousNextCite this article as: Teesdale GN, Wolfe BW, Lowe CG (2015) Patterns of home ranging, site fidelity, and seasonal spawning migration of barred sand bass caught within the Palos Verdes Shelf Superfund Site. Mar Ecol Prog Ser 539:255-269. https://doi.org/10.3354/meps11482 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 539. Online publication date: November 12, 2015 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2015 Inter-Research.

A CD46-like molecule functional in teleost fish represents an ancestral form of membrane-bound regulators of complement activation.

In the complement system, the regulators of complement activation (RCA) play crucial roles in controlling excessive complement activation and in protecting host cell from misdirected attack of complement. Several members of RCA family have been cloned from cyclostome and bony fish species and classified into soluble and membrane-bound type as in mammalian RCA factors. Complement-regulatory functions have been described only for soluble RCA of lamprey and barred sand bass; however, little is known on the biological function of the membrane-bound RCA proteins in the lower vertebrates. In this study, a membrane-bound RCA protein, designated teleost complement-regulatory membrane protein (Tecrem), was cloned and characterized for its complement-regulatory roles. Carp Tecrem, an ortholog of a zebrafish type 2 RCA, ZCR1, consists of four short consensus repeat modules, a serine/threonine/proline-rich domain, a transmembrane region, and a cytoplasmic domain, from the N terminus, as does mammalian CD46. Tecrem showed a ubiquitous mRNA expression in carp tissues, agreeing well with the putative regulatory role in complement activation. A recombinant Chinese hamster ovary cell line bearing carp Tecrem showed a significantly higher tolerance against lytic activity of carp complement and less deposition of C3-S, the major C3 isotypes acting on the target cell, than control Chinese hamster ovary (mock transfectant). Anti-Tecrem mAb enhanced the depositions of carp C3 and two C4 isotypes on autologous erythrocytes. Thus, the present findings provide the evidence of complement regulation by a membrane-bound group 2 RCA in bony fish, implying the host-cell protection is an evolutionarily conserved mechanism in regulation of the complement system.

Fine-scale horizontal and vertical movement of barred sand bass, Paralabrax nebulifer, during spawning and non-spawning seasons

Habitat use, ecotone edge response, activity space size and association with seafloor and thermocline were compared for spawning and non-spawning season barred sand bass (Paralabrax nebulifer). Non-spawning season fish showed affinity with sand/reef ecotone using average activity space areas of 0.003±0.001km2 (±SD) and volumes of 0.00001±0.000005km3 while remaining 1.9±1.7m off the seafloor. Spawning season fish used activity space areas of 0.139±0.370km2 and volumes of 0.001±0.002km3. Spawning season individuals displayed two patterns of behavior, one indicative of spawning and another of resting behavior. Resting individuals tracked during spawning season behaved similarly to fish tracked during the non-spawning season, using smaller activity space areas while associating with reef structures and the seafloor. Presumed spawning individuals utilized sand habitats, using significantly larger activity spaces during the day than at night while associating with the thermocline and making repeated vertical dives toward the seafloor.

Planktonic Larval Duration, Settlement, and Growth Rates of the Young-of-the-Year of Two Sand Basses (Paralabrax nebulifer and P. maculatofasciatus: fam. Serranidae) from Southern California

Accurate estimates of Planktonic Larval Duration (PLD) have become critical to the modeling of larval dispersal and connectivity among ecological communities. Among those species where little information on larval duration is known are the spotted (Paralabrax maculatofasciatus) and barred (P. nebulifer) sand basses, two economically important species that have historically been the focus of marine recreational fisheries off southern California. PLD was determined by a count of the daily growth rings from the otolith core to the settlement check and age from the core to the otolith margin. Size at settlement was estimated by the size of the otolith from its core to the settlement mark based on the otolith size to body size relationship. Based on these significant relationships, mean size at settlement of our specimens was calculated to be 10.2 ± 1.6 mmSL for spotted sand bass and 9.1 ± 1.1 mmSL for barred sand bass. Mean PLD was 32.8 ± 2.2 days with a range from 28 to 37 days for spotted sand bass and 25.8 ± 2.2 days (range 21–30) for barred sand bass. Growth rates for the YOY of each species estimated by calculating the length-to-age relationships were 1.13 mm/day for spotted sand bass and 1.28 mm/day for barred sand bass. PLDs of approximately one lunar month and growth rates of about 1 mm/d seem to be common in those summer spawning fishes from San Diegan Province (warm temperate).

The illusion of plenty: hyperstability masks collapses in two recreational fisheries that target fish spawning aggregations

Fisheries that target fish spawning aggregations can exhibit hyperstability, in which catch per unit effort (CPUE) remains elevated as stock abundance declines, but empirical support is limited. We compiled several fishery-dependent and fishery-independent data sets to assess stock trends in the barred sand bass ( Paralabrax nebulifer ) and the kelp bass ( Paralabrax clathratus ) in southern California, USA, evaluate the interaction between spawning aggregations and fishing activities, and test for hyperstability. Annual and seasonal trends from fisheries and population data indicate that regional stocks of both species have collapsed in response to overfishing of spawning aggregations and changes in environmental conditions. The aggregating behavior of fish and persistent targeting of spawning aggregations by recreational fisheries combined to produce a hyperstable relationship between CPUE and stock abundance in both species, which created the illusion that population levels were stable and masked fishery collapses. Differences in the rate of decline between the two species may be related to the size, duration, and spatial distribution of their spawning aggregations. Results of this study provide empirical evidence of hyperstability in aggregation-based fisheries and demonstrate that CPUE data be used with caution and given low weight when fishery-independent data are available.

Spawning-Related Movements of Barred Sand Bass, Paralabrax nebulifer, in Southern California: Interpretations from Two Decades of Historical Tag and Recapture Data

During the 1960s and 1990s, the California Department of Fish and Game tagged 8,634 barred sand bass in southern California, and 972 fish (11%) were recaptured. Tag returns suggest barred sand bass are transient aggregate spawners that form spawning aggregations consisting of both resident and migrant individuals. Spawning residency at a historic spawning location was estimated by the frequency of returns over time; most same-year returns (82%, n = 141) were recaptured within a 7 to 35-day period. The maximum recapture distance was 92 km. The average (± SD) non-spawning season recapture distance from peak spawning season tagging locations was 13 ± 8 km, and movement was generally northward. A positive relationship existed between fish size (TL) and migration distance to non-spawning season recapture locations. Fish tagged at a presumed non-spawning season residence were primarily recaptured south of the tagging location during peak and late spawning season; the average migration distance was 17 ± 15 km. Recaptures in subsequent years showed a high degree of spawning (80%, n = 135) and non-spawning (73%, n = 11) site fidelity. This is the first documentation of the spawning-related movements of barred sand bass and will be important for informing management decisions regarding this popular sport fish.

Home range, habitat use, and site fidelity of barred sand bass within a southern California marine protected area

Barred sand bass ( Paralabrax nebulifer) is an important recreational species in southern California, which may benefit from marine protected areas. Understanding species movement patterns is a key component to identifying if a species will benefit from marine protected areas. Acoustic telemetry methods coupled with a GIS were used to quantify the home range, site fidelity, and habitat use of barred sand bass at the Catalina Marine Science Center Marine Life Refuge located at Santa Catalina Island, California. Barred sand bass utilized soft-sediment habitats within close proximity to rocky reefs and had home ranges that averaged 10,003 m 2 ± 4773 m 2 (±SD). During the day, individuals generally used multiple areas on or near reefs, and at night repeatedly used one area over soft-sediment habitat. Fifty percent of the acoustically tagged individuals exhibited year round fidelity to the study site indicating that even small marine protected areas may be an effective management strategy.

Reproductive Strategies of Sea Basses based on Larval Abundance in Magdalena Bay, Mexico, 1982–1986

AbstractWe analyzed the reproductive strategies of four sea basses Paralabrax spp. based on larval abundance and sea surface temperature during a period affected by the El Niño of 1982–1983. Zooplankton samples were taken monthly in the Magdalena–Almejas lagoon complex of Baja California Sur, Mexico, from January 1982 to November 1986. Larvae of four sea bass species were recorded; those of the spotted sand bass P. maculatofasciatus were dominant, contributing 43% of total abundance. Barred sand bass P. nebulifer constituted 28% of the sampled larvae, goldspotted sand bass P. auroguttatus contributed 26%, and kelp bass P. clathratus made up 3%. During 1983–1984, the larval abundances of spotted sand bass and goldspotted sand bass decreased (by &gt;50% and 90%, respectively), while the abundance of barred sand bass increased by nearly 25%. A seasonal larval abundance maximum for all species was recorded in summer and autumn, but a differential reproductive pattern inferred from larval abundance was determined. Spotted sand bass showed continuous reproductive activity with peaks in February, June, August–September, and November. Barred sand bass larval abundance indicated one reproductive period with peaks in June and November; a single reproductive period (August) was found for goldspotted sand bass. The abundance of kelp bass larvae was very low, and we were not able to identify a reproductive pattern. Spawning habitat occurred at the relatively narrow temperature range of 19–24°C for spotted sand bass and at 24–28°C for barred sand bass; the widest range was recorded for goldspotted sand bass (22–29°C). The temporal segregation and the differences in spawning habitat permitted the identification of three different reproductive strategies in which there exists a certain degree of overlap. This study represents a first step in understanding the reproductive cycle of three species of sea basses in Magdalena Bay.

Post-Impingement Survival and Inferred Maximum Thermal Tolerances for Common Nearshore Marine Fish Species of Southern California

Abstract The effectiveness of a pilot post-impingement fish return program was studied at Los Angeles Department of Water and Power's Scattergood Generating Station during six heat treatments from February 2005 to August 2006. Species-specific total percent survival was computed for all individuals impinged, with an overall survival of 0.4% across all species impinged during monitored heat treatments, ranging from 30.2% for Paralabrax clathratus to 0.0% for Seriphus politus. Species-specific critical thermal maxima was inferred from surveys of the abundances returned by San Onofre Nuclear Generating Station's highly effective and unique Fish Return System during heat treatments from 2000–2005. Abundant species such as queenfish exhibited low thermal thresholds (15–20°C), while spotfin croaker and barred sand bass became stressed at higher temperatures (25–30°C).

Two factor H-related proteins from the mouse: expression analysis and functional characterization

Complement factor H-related (FHR) proteins display structural and functional similarities to each other and to the complement regulator factor H (FH). FHRs have been identified in various species, including human, rat, and the fish barred sand bass. As mice provide a useful model system to study the physiological role of FHRs in vivo, we aimed at characterizing murine FHR proteins. Two putative FHRs of approximately 100 and 38 kDa were detected in mouse plasma using FH-specific antiserum. In a liver cDNA library, three murine FHR-encoding transcripts were identified. Two clones code for related FHR proteins termed FHR-C and FHR-C_v1, which in secreted form are composed of 14 and 13 short consensus repeat (SCR) domains, homologous to SCRs 6-17 and 19-20 of FH. The third transcript, FHR-B, is derived from a separate gene and codes for a secreted protein composed of five SCR domains. FHR-B displays homology to SCRs 5-7 and 19-20 of FH. Expression of FHR-B in various tissues was analyzed by real-time polymerase chain reaction and was identified at high levels in liver, kidney and heart. In liver, FHR-B transcript level was even higher than that of FH. In addition, FHR-B was expressed as a recombinant 37-kDa protein, and this recombinant FHR-B interacted with the ligands heparin and human C3b. Using mouse plasma, the native presumptive FHR proteins were also analyzed in binding assays. In summary, we identify two FHR proteins in mice and for the first time characterize a murine FHR as a heparin- and C3b-binding protein.

Phylogeography of the spotted sand bass, Paralabrax maculatofasciatus: divergence of Gulf of California and Pacific Coast populations.

Have the warm tropical waters and currents of the southern Gulf of California, Mexico (also known as the Sea of Cortez), formed a barrier to gene flow, resulting in disjunct populations in the upper gulf that are isolated from the outer Pacific Coast? Phylogeographic and genetic divergences of the spotted sand bass, Paralabrax maculatofasciatus, from three Gulf of California and two outer Pacific coastal locations were tested using mitochondrial DNA (mtDNA) control region sequences. Sequence data from two congeners that are sympatrically distributed along the outer Pacific Coast, the barred sand bass, P. nebulifer, and the kelp bass, P. clathratus, were used to gauge the levels of genetic divergences. Differences among the three species and between the northern gulf and outer Pacific coastal populations of P. maculatofasciatus also were analyzed using 40 allozymic presumptive gene loci. Allozyme and mtDNA analyses each revealed many fixed differences among the species. Three significant allozymic frequency differences and two fixed mtDNA substitutions differentiated the gulf and outer Pacific coastal populations of P. maculatofasciatus. Three unique mtDNA haplotypes and three unique allozyme alleles were identified from the outer Pacific coastal population. The gulf sites contained four unique mtDNA haplotypes and six unique allozyme alleles. Partitioning of the mtDNA variation revealed that 72% of the variance occurred between the gulf and outer Pacific Coast, 20% between sampling sites in the two regions, and 8% within the sites. There appears to be little gene flow across the waters of the southern Baja Penninsula, producing divergence estimated as 120,000 to 600,000 years between the outer Pacific coastal and the Gulf of California populations. This separation level may date to a hypothesized seaway closure near La Paz, Mexico, during the mid-Pleistocene, and characterizes other fish populations. A second pattern of deeper allopatric species-level divergences in some other fishes may date to a Pliocene closure of a mid Baja Penninsular seaway. Significant differences also were discerned in P. maculatofasciatus between the San Diego and central Baja California coastal sites and between the upper/central and the lower gulf locations. Variation between locations in the two regions may be indicative of larval retention and low adult migration, which needs to be tested further.