Southern Fish Research Articles

Regional Characteristics Affecting Distribution of Plain Sculpin Myoxocephalus jaok (Cottidae) in the Russian Territorial Waters in the Sea of Japan

Two intraspecific groups of the plain sculpin Myoxocephalus jaok inhabiting the Russian territoral waters in the Sea of Japan, representing the northern and southern species groups, have been revealed. In a summer season, the species groups are separated from each other by a wide water area extending from 45° to 48° N. The northern species-group nucleus in this period is located in the Tatar Strait inlet, while the southern species group inhabits the Peter the Great Bay. In the summertime, the plain sculpin prefers the upper slope shelf area with water column depths ranged from 80 m (for the southern species group) to 60 m (for the northern species group). The juvenile fish tend to be found in shallower waters as opposed to the mature fish. In a cold season, the majority of fish stocks of the southern species group is still congregating in the Peter the Great Bay, shifting to the shelf edge and the continental slope. Some porton of male fish remains at spawning grounds in the coastal zone to the springtime to guard egg clutches. The specimens of the nothern group leave the shallow-water Tatar Bay inlet at massive level to congregate over the winter in the locations of a deep-water area off the mid-coastal zone of the Sakhalin Island. The specimens of the northern group reach the body length of 67 cm, while the sizes in the southern fish group are larger, reaching 75 cm in length.

Gene expression and latitudinal variation in the stress response in Fundulus heteroclitus

Atlantic killifish, Fundulus heteroclitus, are intertidal marsh fish found along the east coast of North America. Associated with the thermal gradient along this coast, northern and southern killifish populations are known to differ in morphology, behavior, and physiology, including in their cortisol stress response. Our goal was to explore population differences in the stress response and identify underlying molecular mechanisms. We measured responses to both acute and repeated stress in plasma cortisol, stress axis mRNA expression, and body condition in northern and southern killifish. Following an acute stressor, the southern population had higher cortisol levels than the northern population but there was no difference between populations following repeated stress. In the brain, both corticotropin releasing factor and its binding protein had higher expression in the southern than the northern population, but the northern population showed more changes in mRNA levels following a stressor. In the head kidney, Melanocortin 2 Receptor and steroidogenic acute regulatory protein mRNA levels were higher in the southern population suggesting a larger capacity for cortisol synthesis than in the northern fish. Lastly, the glucocorticoid receptor GR1 mRNA levels were greater in the liver of southern fish, suggesting a greater capacity to respond to cortisol, and GR2 had differential expression in the head kidney, suggesting an interpopulation difference in stress axis negative feedback loops. Southern, but not northern, fish were able to maintain body condition following stress, suggesting that these differences in the stress response may be important for adaptation across latitudes.

«Wrong fish» or wrong hypotheses: what happens to nekton of the Pacific waters at Kuril Islands?

A phenomenon of undulating fluctuations of nekton abundance in the Kuroshio system is discussed on example of japanese sardineSardinops melanostictus, as the most abundant and the most fluctuating species. The so-called «sardine epochs» are distinguished according to this species abundance. The last such epoch ended in the early 1990s. Since 2014, structural changes occurred again in the nekton communities of the Pacific waters off Kuril Islands, caused by expansion of southern fish and squid species, primarily japanese sardine and chub mackerelScomber japonicus, and decreasing in abundance of japanese anchovyEngraulis japonicusand sauryCololabis saira. The scope of these changes allowed Russian fishermen to resume the fishery on japanese sardine and chub mackerel in the Russian exclusive economic zone since 2016. Annual catch of Japanese sardine increased steadily from 6,700 t in 2016 to 315,500 t in 2020. Over these 5 years, Russian fishermen landed 531,700 t of sardine and 167,900 t of chub mackerel. However, many Russian fishery forecasters believe that these reconstructions is only a «rehearsal» of the upcoming «sardine epoch», being based on formal climatic indices, without delving into the mechanisms of abundance fluctuations. The authors note that new «sardine epochs» cannot be predicted as completely similar to the previous ones. Several hypotheses on causes of the beginning and end of japanese sardine blooms are considered critically, and the conclusion is made that mechanisms which determine its year-classes strength are still unclear, as well as the reasons of undulating fluctuations of this species and some other nekton species abundance, because of high complexity of this problem.

Ichthyofauna biodiversity of freshwater lakes in the Murmansk Region

The Arctic ichthyofauna has low biodiversity and includes 460 species of fish (2.0% of the world fauna); less than a third of them are freshwater species. There are less than 20 indigenous species in the lakes of the Murmansk Region. Salmoniformes, Perciformes, Osmeriformes, and Cypriniformes build the community core. The species diversity in the lakes of the Kola Peninsula is stable, but there is insignificant growth in the number of species due to the unintentionally introduced aquaculture objects. Water bodies sometimes successfully naturalize the latter. Illegal fishing dramatically causes the disappearance of valuable species in some lakes. Global warming has not yet influenced the penetration of southern fish species. The expansion of native species in new water bodies is the reason for the most critical changes. Unimportant smelt

Spatio-Temporal Variations in Co-Occurrence Patterns of Fish Communities in Haizhou Bay, China: Null Model Analysis

Co-occurrence pattern of fish species plays an important role in understanding the spatio-temporal structure and the stability of fish community. Species coexistence may vary with time and space. The co-occurrence patterns of fish species were examined using the C-score under fixed-fixed null model for fish communities in spring and autumn over different years in the Haizhou Bay, China. The results showed that fish assemblages in the whole bay had non-random patterns in spring and autumn over different years. However, the fish co-occurrence patterns were different for the northern and southern fish assemblages in spring and autumn. The northern fish assemblage showed structured pattern, whereas the southern assemblage were randomly assembled in spring. The co-occurrence patterns of fish communities were relatively stable over different years, and the number of significant species pairs in northern assemblage was more than that in the southern assemblage. Environmental heterogeneity played an important role in determining the distributions of fish species that formed significant species pairs, which might affect the co-occurrence patterns of northern and southern assemblages further in the Haizhou Bay.

Latitudinal Growth Variation in Young Tautogs: A Field, Laboratory, and Growing Degree‐Day Assessment of Potential Intrinsic Differences in Growth Responses to Temperature

AbstractA difference in size at age of young Tautogs Tautoga onitis has been reported from two sites in the Mid‐Atlantic Bight, USA, whereby southern fish (Virginia [VA]) reach a twofold greater size than northern fish (Rhode Island [RI]) by age 1 but grow at similar size‐dependent annual rates thereafter. We investigated the basis for this difference by using a coordinated field, laboratory, and growing degree‐day (GDD) approach. Age‐0 Tautogs were sampled from three locations (Chesapeake Bay, VA; Delaware Bay, Delaware [DE]; and Narragansett Bay, RI) and showed a clinal relationship of decreasing fish size and growth rate with increasing latitude. Otolith‐based estimates of larval stage duration and growth rate showed no significant clinal relationship. Young Tautogs from these locations were reared in common‐garden experiments (at 5, 15, and 25°C) to determine whether there were intrinsic postsettlement growth differences related to temperature. None of the location‐specific groups of age‐0 Tautogs exhibited growth that was consistently faster than that of Tautogs from the other locations over all temperatures examined. These data and the results of a GDD assessment between VA and RI indicate that latitudinal differences in temperature regime and growing season length are the major factors determining latitudinal growth differences in age‐0 fish. However, age‐1 RI fish of equivalent size grew significantly faster than age‐0 RI and DE fish and similar to age‐0 VA fish at 15°C and grew 40% faster than all age‐0 fish at 25°C, suggesting countergradient growth variation in age‐1 and older northern Tautogs. Size‐selective overwinter mortality of age‐0 northern fish—whereby smaller individuals are most susceptible to low temperature—is proposed as the likely underlying mechanism leading to faster growth of older northern fish at temperature. Such a mechanism would at least partially compensate for the lower temperature and shorter growing season at higher latitudes.

New records of two southern fishes found in northern waters of the Iberian Peninsula

New records of two southern fishes found in northern waters of the Iberian Peninsula

Variation in the ontogeny of sex steroid levels between latitudinal populations of the medaka.

IntroductionSex steroids mediate the expression of sexual dimorphism during ontogeny, and populations that differ in the magnitudes of sexual dimorphism may accordingly differ in the ontogenetic patterns of their sex steroid levels. The medaka, Oryzias latipes species complex, shows geographic variation in the magnitude of sexual dimorphism with respect to the lengths of their anal and dorsal fins; dimorphism is greater in low-latitude populations than in high-latitude populations. However, sexual differences in the ontogenetic dynamics of sex steroids, and its interpopulation variation, have not been examined.ResultsWe measured testosterone (T), estradiol-17β (E2), and 11-ketotestosterone (11-KT) concentrations throughout ontogeny of laboratory-reared fish from two latitudinal populations: Aomori (northern) and Okinawa (southern). In both populations, the levels of all three steroids were high during early ontogenetic stages and decreased with growth. After reaching about 15 mm in standard length, when sexual dimorphisms in fin lengths became apparent, steroid levels increased and tended to plateau. Sexual differences in the steroid levels were observed only in the later ontogenetic stages; T and 11-KT levels were higher in males, while E2 levels were higher in females. Accordingly, interpopulation differences also became clearer; the southern fish tended to show higher T levels and lower E2 levels than the northern fish.ConclusionsThe ontogenetic patterns of sex steroid levels paralleled the ontogeny of anal and dorsal fins in the two latitudinal populations, suggesting that interpopulation variation in the degree of sexual dimorphisms in fin lengths is mediated by sex steroid-dependent regulation of fin elongation.

Is the Russell Cycle a true cycle? Multidecadal zooplankton and climate trends in the western English Channel

The Russell Cycle is one of the classical examples of climate influence on biological oceanography, represented as shifts in the marine plankton over several decades with warm and cool conditions. While the time-series data associated with the phenomenon indicate cyclical patterns, the question remains whether or not the Russell Cycle should be considered a “true cycle”. Zooplankton time-series data from 1924 to 2011 from the western English Channel were analysed with principal component (PC), correlation and spectral analyses to determine the dominant trends, and cyclic frequencies of the Russell Cycle indicators in relation to long-term hydroclimatic indices. PC1 accounted for 37.4% of the variability in the zooplankton data with the main contributions from non-clupeid fish larvae, southwestern zooplankton, and overall zooplankton biovolume. For PC2 (14.6% of data variance), the dominant groups were northern fish larvae, non-sardine eggs, and southern fish larvae. Sardine eggs were the major contributors to PC3 (representing 12.1% of data variance). No significant correlations were observed between the above three components and climate indices: Atlantic Multidecadal Oscillation, North Atlantic Oscillation, and local seawater temperature. Significant 44- and 29-year frequencies were observed for PC3, but the physical mechanisms driving the cycles are unclear. Harmonic analysis did not reveal any significant frequencies in the physical variables or in PCs 1 and 2. To a large extent, this is due to the dominant cycles in all datasets generally being long term (>50 years or so) and not readily resolved in the examined time frame of 88 years, hence restricting the ability to draw firm conclusions on the multidecadal relationship between zooplankton community dynamics in the western English Channel and environmental indices. Thus, the zooplankton time-series often associated and represented as the Russell Cycle cannot be concluded as being truly cyclical.

Distribution, abundance and biology of polar cod, Boreogadus saida, in Iceland–East Greenland waters

Recent warming has caused a northern extension in the distribution of many southern fish species in Icelandic waters. Polar cod (Boreogadus saida) around Iceland are near the southern limit of their distribution, but are poorly studied in the area. Therefore, material sampled during demersal fish surveys in March 1985–2013 and in pelagic 0-group surveys in Iceland–East Greenland waters in August–September 1974–2003 was used to investigate their distribution, abundance and biology. Demersal polar cod were most often caught on the outer shelf to the north-west and north of Iceland, but during years of widest distribution and highest abundance, they were caught farther to the east on the northern shelf. Pelagic 0-group polar cod were only caught sporadically and mainly confined to the waters off the north-west shelf of Iceland and the East Greenland shelf (southern Denmark Strait). In demersal hauls, the number of stations with polar cod decreased with increasing bottom temperature and polar cod were most widely distributed in the years 1989, 1994 and 1995. Highest numbers of demersal polar cod per haul were caught at temperatures of −0.5 to 2.5 °C and at 200–450 m depth. The length of demersal polar cod ranged from 5 to 32 cm, while the fish caught in the pelagic trawl ranged from 2.2 to 19 cm. The polar cod in the subarctic waters north of Iceland most likely originate from the waters off East Greenland and further warming and decline in sea ice may eventually lead to the disappearance of polar cod from Icelandic waters.

History, Place, and Power: Studying Southern Food

[ILLUSTRATION OMITTED] Two moments help explain my interest in bringing food to the pages of Southern Cultures. first is a conversation I've had more frequently than I can recall as I worked on my recent book, Edible South, which explores the intersection of southern food and social history. Them: Wow, southern food! How come they fry everything? Me: Excuse me? Them: You know, southern food is SO BAD for you. BAD. BAD. BAD. They fry everything. Why do they do that? Me: Oy. second experience was a request to speak to a lively group of UNC undergraduates who study local sustainable food systems. Them: Could you briefly speak about the role of southern culture in local Me: Oy. Why all the oys? Because the southern history embedded in southern food has somehow disappeared. In contemporary worlds of popular and consumer culture, southern food has become untethered from the complex historical narrative responsible for this cuisine. Think buckets of southern fried chicken and cathead biscuits like culinary spacecraft set adrift from the mother ship of southern history, culture, and experience. A multi-layered past and present underlies these foods and explains why southerners eat the way they do, and why we think of these foods as deeply southern. Food is history. Food is place. Food is power and disempowerment. When we examine the history of food in the American South, we encounter the tangled interactions of its people over time, a world of relationships fraught with conflict, yet bound by blood and attachment to place. We viscerally experience this in Bernie Herman's exegesis on Spot, a fish uncommonly common in the lower Chesapeake and North Carolina's sounds. In this convincing fish story lies a many-layered narrative of place, taste, and memory that emanates from the docks, marketplaces, gill nets, and tables of the Eastern Shore of Virginia. There are more fish tales--and those of the region's beloved pig, too--shared throughout the South, as seen in Tom Rankin's evocative photographs of the daily rituals and work that bring food to the table, from rural southern fish markets to hog killings. Here, the contradiction between the realities of plenty and deprivation, of privilege and poverty in southern history resonates in the region's food traditions. In these worlds the ordinary becomes extraordinary, as a hand-painted sign advertising FISH becomes art, and a good catch, a fat pig, and, ultimately, a satisfying meal bring joy and satisfaction to southerners drawn together by food-related labors passed down between generations. What is southern food? Can we define it? Can there be one southern cuisine when there isn't one southern culture? South is a region of cultural, historical, geographic, and demographic complexity. As Sarah Spencer ('14), a student in our Introduction to Southern Studies course noted at the end of the spring 2014 semester, The South is MESSY! Marianne Gingher conjures this messiness in her essay of new love, then lost love, and the persuasive power of classic southern cooking, in particular, the culinary big guns of grandmother-authenticated, irresistible cakes and pies. Amy Evans evokes these feminine worlds in her portraits, evocative foodscapes filled with familiar culinary icons and ephemera of southern life. We are honored to include her work again on these pages--a powerful photo essay from Amy appeared in a previous food issue of Southern Cultures. Today, we recognize Evans's twelve years as the visionary lead oral historian for the Southern Foodways Alliance, where she built the documentary program and oversaw the collection of more than 800 life stories behind the South is a world so shaped by history and memory that it is difficult to separate myth from reality. same is true for southern food. Fried chicken, biscuits, and sweet tea, too--the icons of southern food--are so super-sized, enriched, sweetened, and filled with butter that they are almost unrecognizable to native southerners. …

The Regulation of β-arrestin1 in Leukemia Initiating Cells of Children B-Acute Lymphoblastic Leukemia

BackgroundLeukemia is the most common malignant tumor in children under 15 years old. The main subtype of children leukemia is acute lymphoblastic leukemia (ALL), and B-lineage ALL (B-ALL) accounts for approximately 70%. The leukemia-initiating cells (LICs) are cancer stem cells with long-term repopulating potential and propagation ability, to maintain the leukemia cell phenotype, and possess leukemia-initiating activity. However, the regulation of LICs for the leukemia progression is poorly understood. The multifunctional scaffold proteins β-arrestins are proven to mediate H4 acetylation and gene expression. And β-arrestin2 is found to regulate the initiation and progression of chronic myeloid leukemia (CML). However, the role of β-arrestin1 in B-ALL is still unknown. Our preliminary data showed that both the high expression of β-arrestin1 and high proportion of CD34+CD38- cells are positively correlated with risk stratification and poor prognosis of childhood B-ALL. And β-arrestin1 binds with EZH2 to increase BCR/ABL H4 acetylation and thus promotes CML cell progression in vitro and in vivo. The aim of study is to investigate the essential function of β-arrestin1 in LICs from B-ALL.Materials and MethodsThe bone marrow (BM) and periphery blood (PB) of children B-ALL patients were collected, isolated and identified LICs by Magnetic-activated cell sorting (MACS) and flow cytometry. The total RNA and protein were purified for gene and protein expression by real-time RT-PCR and Western blot. The leukemia cells (LICs, Raji, and Reh) of β-arrestin1 depletion were constructed by transient or stable screening si-β-arrestin1 (siβ1) lentivirus vector. The serial cell colony formation and NSG mice survival analysis was measured the LICs self-renewal ability. The CCK8 and MTS assays were used to detect the cell proliferation, and annexin V-FITC and PI staining for cell apoptosis. The DNA methylation of gene promoter region was detected by methylation-specific PCR and the methltransferase activity by ELISA. The telomere length was indicated by Southern blot and FISH, and telomerase activity by TRAP. Electrophoretic mobility shift assay (EMSA) and dual-luciferase reporter assay were applied to explain gene transcription. Student’s t test and Log-Rank test were used in the corresponding statistical significance and P<0.05 were considered significant. All the statistical analysis was performed using the GraphPad Prism (Version 5.0) software packages and SPSS 17.0.ResultsThe expression of β-arrestin1 was elevated in LICs from B-ALL patients, and the high level of β-arrestin1 was negatively correlated with the survival of these patients. Further study showed that the loss of β-arrestin1 in B-ALL LICs attenuates their self-renewal capacity and promotes their senescence in vitro and in vivo. The mRNA expression level of β-arrestin1 is negatively correlated with that of PTEN in LICs. Moreover, the DNA methylation of the PTEN promoter region, the activity and the expression of DNMTs were enhanced in the LICs. The inhibition of DNMT1 activity impaired the self-renewal and increased the expression of PTEN of LICs. In addition, depletion of β-arrestin1 significantly decreased DNMT1 activity and PTEN methylation, and consistently increased PTEN expression in LICs. For B-ALL cell senescence, the mRNA expression level of β-arrestin1 is negatively related with the length of telomere, positively related with the activity of telomerase and the mRNA expression of hTERT in B-ALL LICs and engrafted NSG mice. Moreover, the weakened effect of β-arrestin1 on telomere, telomerase and the gene of hTERT were observed by injected the inhibitor of telomerase in leukemic mice. In addition, depletion of β-arrestin1 significantly decreased the binding of SP1 to the promoter of hTERT and thus reduced the transcription of hTERT in B-ALL Raji and Reh cells. Furthermore, β-arrestin1 interacted with P300 to bind with SP1 in the -104bp to -113bp of hTERT core promoter region in B-ALL cells.Conclusionsβ-arrestin1 could regulate the self-renewal and senescence of LICs from B-ALL, by partially mediating DNMT1 activity and hTERT transcription respectively, indicating that β-arrestin1 is a potential therapeutic target for B-ALL. DisclosuresNo relevant conflicts of interest to declare.

Contrasting evolution of a satellite DNA and its ancestral IGS rDNA inPhaseolus(Fabaceae)

CC4 is a satellite DNA from common bean (Phaseolus vulgaris L.) that is similar to its intergenic spacer (IGS) rDNA. CC4 was originally hypothesized to be an old, fast evolving satellite family that has invaded common bean rDNA. To test this hypothesis and contribute to the understanding of IGS-like satellite DNA evolution, we have investigated its distribution in the genus Phaseolus and related species. CC4 was cloned and used as probe for Southern blot and FISH experiments. CC4 was observed as an independent satellite in common bean, forming two to three major and a few minor pericentromeric clusters. In Phaseolus coccineus, CC4 was present in four major clusters, also not co-localized with the 45S rDNA sites. Remarkably, in the less related species of the genus, signals were detected co-localized with the 45S rDNA sites, but co-localization was not observed in the species where CC4 is present as an independent satellite. No signal was detected in species from related genera. Altogether, the data suggest that CC4 has originated from the IGS rDNA in the P. vulgaris-P. coccineus lineage and has evolved slower than the IGS rDNA from this lineage.

Do surf zones in New Jersey provide “nursery” habitat for southern fishes?

The fishes of the energetic surf zone of exposed ocean beaches are poorly known, especially along the U.S. east coast. We investigated the role that surf zones in southern New Jersey have as habitat by describing the young-of-the-year fishes caught by seines within the surf zone from May through October in 1998, 1999, 2005 and 2006. In addition, we investigated the nursery role of these surf zones by examining abundance, growth, and inferred survival during the summer for the dominant locally (New Jersey) and southern (south of Cape Hatteras) spawned species. At least three southern species, i.e. bluefish Pomatomus saltatrix (Cohort I), white mullet Mugil curema, and Florida pompano Trachinotus carolinus successfully use New Jersey surf zones as nurseries during the summer. It is clear that bluefish (Cohort I) contributes to the adult population and it is likely for the other southern species. Ultimately, the nursery contribution of surf zones and other habitats at the northern limits of the range of southern species depends on whether surviving juveniles can successfully emigrate to overwinter habitats and complete their life history.

In Memoriam: John (Jack) F. Dequine, 1917–2011

Jack graduated from the University of Maine in 1940. After a brief time overseas, Jack took a position as the chief of fisheries for the Kentucky Game and Fish Commission and shortly thereafter moved to Florida in 1946 as the first fishery biologist for the Florida Game and Freshwater Fish Commission. Much of Jack's work in the late 1940s and early 1950s attempted to resolve conflicts between commercial and recreational fishing interests and to properly establish rules governing take of freshwater fishes. Jack was dedicated to using science to inform management actions, rather than making decisions based solely on popular public sentiment. Jack left the agency in 1954 and started Southern Fish Culturists, Inc., a private production and environmental consulting business related to fish, fisheries, and aquatic resources. As a businessman, Jack was known as someone that you could call anytime and get a helpful response. Jack is appropriately recognized as a founding father, energetic leader, and persistent supporter of the SDAFS. Following the AFS (parent society) annual meeting in 1947, Jack and colleagues approached the directors of the Southeastern Association of Game and Fish Commissioners, who endorsed the concept of inclusion of a fisheries component at their annual meetings. The first such meeting was held in St. Petersburg, Florida, in November 1947. Jack spearheaded a working group to successfully petition AFS for recognition as the Southern Division and was officially elected first president of the SDAFS in Dallas, Texas, in September 1952. The first official session of the SDAFS followed in October 1952 at the southeastern meeting held in Savannah, Georgia. About 40 fisheries workers representing all Southeastern states, academia, and federal agencies were in attendance and affirmed Jack Dequine as the first president of the division. The 2002 Southern Division Meeting represented the 50th anniversary of this important event, and Jack attended this celebration. Perhaps Jack's greatest accomplishment and contribution to the AFS was the creation and maintenance of AFS award programs that recognize and encourage excellence in fisheries professionals. In 1967, Jack and other members of a former-presidents committee recommended the establishment of a best paper award to recognize excellence of fisheries contributions at the annual Southeastern conference. He served as chair of the division's awards committee from its inception in 1967 through 1987 (21 years of service). In 1979, Jack led new efforts to create a second type of award for fisheries professionals in the south, the Outstanding Achievement Award. This award remains the most prestigious offered by the Division by recognizing significant long-term individual contributions to the field of fisheries and aquatic biology. Through these awards, and by his encouragement and personal example, Jack influenced the professional development of fisheries biologists throughout the southeast. Over the years Jack remained involved with many important Division activities. He attended nearly all of the SDAFS meetings in the past 60 years. Jack was a fastidious compiler of correspondence and other paperwork relevant to business of the Division, and he maintained a set of files that was essentially complete through the mid-1980s. Jack's perennial presence at Division business meetings and past-presidents’ meetings provided continuity of conduct and an infallible corporate memory. As late as January 2011, Jack presented the award in his name (John F. Dequine Best Paper Award) to Eric Nagid and coauthors at the SDAFS annual meeting, Tampa, Florida, and he escorted incoming SDAFS First Vice President M. Allen into office at that same conference. Along the way Jack continued his lifelong hobbies of hunting and fishing. He fished with the authors of this tribute regularly over the last decade, sharing his history, humor, and wisdom. He harvested a large turkey gobbler in spring 2011, and well into his 90s Jack also hunted deer in Georgia with M. Van Den Avyle and Bob Garrett. Jack is survived by daughters Jeanne and Joy, of Miami, Florida. He will be remembered and missed by his friends, family, and the AFS. We offer this as a celebration of his life and his accomplishments, from which all of us in the AFS have benefited. We are grateful for his friendship, for the opportunities we shared afield with him, and for his mentorship.

Cytogenetic and molecular analysis of the holocentric chromosomes of the potato aphid Macrosiphum euphorbiae (Thomas, 1878)

Cytogenetic and molecular investigations on the holocentric chromosomes of the aphid Macrosiphum euphorbiae (Thomas, 1878)have been carried out using silver staining and C-banding (followed by chromomycin A3 and DAPI staining) in order to improve our knowledge about the structure of aphid chromosomes. The C-banding pattern is peculiar since only the two X chromosomes and a single pair of autosomes presented heterochromatic bands. Silver staining and FISH with the 28S rDNA probe localized the rDNA genes on one telomere of each X chromosome that were also brightly fluorescent after chromomycin A3 staining of C-banded chromosomes, whereas all other heterochromatic bands were DAPI positive. Interestingly, a remarkable nucleolar organizing region (NOR) heteromorphism was present making the two X chromosomes easily distinguishable. Southern blotting and FISH assessed the presence of the (TTAGG)n repeat at the ends of all the Macrosiphum euphorbiae chromosomes. Karyotype analysis showed that all males possessed the X chromosome with the larger amount of rDNA suggesting a non-Mendelian inheritance of the two X chromosomes.

Exposing local adaptation: synergistic stressors elicit population-specific lactate dehydrogenase-B (ldh-b) expression profiles in Australian barramundi, Lates calcarifer

The molecular response of fish to independently and/or concurrently applied ecological stressors (e.g. thermal and/or aerobic stress) can be quantified at the level of transcript abundance (i.e. gene expression). In temperate fish, the expression of the metabolic candidate gene lactate dehydrogenase-B (ldh-b) responds to both aerobic swimming challenge and extended acclimation to various ecologically relevant temperatures. We examined hepatic ldh-b expression in juvenile Lates calcarifer from two geographically, genetically and thermally distinct Australian populations to determine if similar environmental stressors also influence the transcription of this locus in a tropical fish. Hepatic ldh-b expression was quantified following 28-day acclimation to ecologically relevant temperatures (20, 25, 30 and 35°C). Expression was also quantified in L. calcarifer subjected to aerobic swimming challenge at these temperatures. Fish from southern (high latitude) and northern (low latitude) populations within this species’ Australian distribution exhibited a significant increase in hepatic ldh-b expression following aerobic swimming challenge at native temperatures of 25 and 30°C, respectively (p < 0.001). Southern and northern fish also exhibited significant increase in hepatic ldh-b expression (p < 0.001 and p < 0.01, respectively) following 28-day acclimation to heat-stress (35°C). However, only southern fish exhibited significant increase in expression (p < 0.001) following 28-day acclimation to cold-stress (20°C). The novel evidence presented herein suggests that (a) transcription of hepatic ldh-b is responsive to both aerobic and thermal stress when applied independently, and (b) southern Australian L. calcarifer populations may be locally adapted to cooler seasonal water temperatures.

Ontogenetic variation in fin ray segmentation between latitudinal populations of the medaka, Oryzias latipes

Fin rays of ray-finned fishes are composed of multiple bony segments, and each fin ray elongates by adding a new segment to the tip. Therefore, fin ray length is determined by the number of segments and the length of each segment. A comparison of the anal fin rays of a northern and southern wild population of the medaka, Oryzias latipes, revealed that southern fish had more segments per fin ray, resulting in longer anal fins than the northern fish. When fish were reared in a laboratory common environment, segmentation of the fin rays started earlier with respect to body size in the southern fish. In the southern males, moreover, the rate of segment addition accelerated after a certain body size, indicating sexual maturity. These patterns of segment addition during ontogeny were consistent with the patterns of fin ray elongation. Although distal segments tended to be longer, except for the most proximal segment, in both populations, the southern fish had shorter segments than the northern fish at any position on fin rays. These results indicate that the interpopulation variation in fin length is largely due to genetically-based differences in the control of segment addition, and that the length of each segment does not contribute to it. We suspect that fin ray segmentation is regulated by thyroid and sex hormones that differ between populations. We also found that some segments fuse with each other at the base of each fin ray, the functions and mechanisms of which remain unclear.

Caracterización molecular de dos nuevas mutaciones de α° talasemia en 2 familias españolas (mutación -- ED y -- GP)

Background and objetives The two structural genes encoding the human α-globin chains are located on the short arm of chromosome 16. Normal individuals have four genes α (αα/αα). α-thalassemias are usually produced by the deletion of one, two, three, or four α genes. Deletion of both α genes within the same chromosome (α° thalassemia) is commonly observed in individuals from the Mediterranean basin and Southeast Asia. Material and methods We study two natural families of Madrid with microcytic hypochromic anemia. The DNA extracted from peripheral blood leukocytes was digested with different restriction enzymes and hybridization with probes of gene cluster α. The ends of the deletion were characterized by combining the techniques of Southern blot, PCR and FISH. Results We present two new mutations of α° thalassemia in two Spanish families, not previously described in the literature. The deletion (-- ED) is ∼80 kb with the point of bread 5’ in the coordinate +100 (± 3 kb), whereas the end 3’HVR places in the coordinate 178 ± 750 bp. The second deletion (-- GP) is more extensive, with loss of 145 kb, placing the deletion in the end 5’ between the coordinates 34 and 37, respecting therefore the telomere. In the centromeric region the point of break places as the previous one in the coordinate 178 ± 1.4 bp. Conclusions In both mutations both alpha genes were deleted, the gene θ and the region HS40. The exact identification of these deletions is essential to determine the function of the genes α with a view to a possible genetic diagnosis.

The presence of southern fishes in the Argentinian continental shelf and adjacent areas

A list of Southern Ocean fishes captured in the Argentinian continental shelf and adjacent areas is presented. The list comprises a total of 41 species. They represent 15% of the ichthyofauna registered in the Southern Ocean. The geographic position of the samples was considered in order to show the northward displacement of some Antarctic species toward southwestern Atlantic waters.