DOCSLIB.ORG

<I>Aplysia Californica</I>

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
<I>Aplysia Californica</I> Temperature Eff ects on Growth, Maturation, and Lifes- pan of the California Sea Hare (Aplysia californica) DUSTIN STOMMES, BLA, LYNNE A. FIEBER, PHD,* CHRISTINA BENO, ROBERT GERDES, MS, and THOMAS R. CAPO, BS We conducted a hatchery growth study to describe the variability in growth rates, spawning, and mortality of Aplysia californica in regard to rearing temperature. Animals were housed at a standard hatchery density of fi ve animals per cage, at temperatures of 13, 15, 18, and 21°C. Animals reared at 13 or 15°C grew as much as four times as large, lived twice as long, matured later, and spawned longer than did animals reared at 18 or 21°C. At age 170 to 205 days the fastest growth rates occurred at 18 and 21°C, and the slowest at 13°C. As animals at 18 and 21°C reached sexual maturity at ages 190 to 197 days, or ∼60% through their lifespans, their growth rates slowed such that by age 260 days, the fastest growth rate was at 13°C, and the slowest was at 21°C. Animals reared at 13 and 15°C reached sexual maturity at 242 and 208 days, respectively, or at ∼40% of their life spans. Lifespan and maximum average animal weight were signifi cantly inversely correlated with temperature (P ≤ 0.0001). However, there were no signifi cant diff erences at any temperature in the age at which maximum animal weight was reached when this age was expressed as a percentage of the life span: animals reached their maximum weight at ∼80% of their life span. Aging rate was highest for animals reared at 21°C, while the mortality rate doubling time was lowest at this temperature. Th is would be expected for the accelerated lifecycle observed at higher temperatures. Aplysia californica has a natural lifespan of approximately 1 year Materials and Methods (3), that is preserved in hatchery animals reared at 15°C during their Rearing experiments under diff erent experimental temperatures post-metamorphic life (5). As is the case for all ectothermic organisms, were conducted at the University of Miami, National Institutes of the growth rate is temperature-dependent. Several laboratory stud- Health National Resource for Aplysia, from June 1996 through ies of A. californica have documented these rates at diff erent rearing September 1997. Th is facility is equipped with continuously fl ow- temperatures (5, 11, 15, 18). ing 50-μm fi ltered and chilled seawater, an indoor animal-rearing A. californica is laboratory-reared to provide experimental ani- laboratory, and an outdoor macro algae culture facility that provides mals for researchers working on this neurobiological model species. food year round (5, 7). Recently we have been studying factors that infl uence growth in labo- Th e experimental set-up for rearing was as described in detail by ratory-reared A. californica maintained under controlled conditions. Capo and coworkers (5). Briefl y, 100 animals from a single egg mass In these studies, we varied one factor such as temperature, food or of wild-caught broodstock were used. At the start of the experiment stocking density, while keeping the others constant (5, 6, 11). Th ese ± (ta), the age of the animals was 170 days, and live weights (mean studies demonstrated that each factor had a strong eff ect on growth standard deviation) were 4.6 ± 0.22 g with the narrow weight range rate and size at sexual maturity. One factor that does not appear to of 4.22 to 5.10 g. Animals were distributed randomly among the four infl uence growth and maturation, however, is the time of year the temperature treatments. Feeding in these animals prior to the begin- life cycle begins (10, 14, 18). Th erefore it is possible to customize ning of the experiment was not ad libitum; feedings were four times animals for researchers’ needs throughout the year by manipulating per week at 430% of body weight per feeding in 3-g animals. Animals growth rate or size and age at sexual maturity. were housed in 16-liter polycarbonate cages submerged in fi berglass We hypothesized that rearing temperature would infl uence the troughs through which chilled, fi ltered seawater fl owed continuously growth rate and the age at which A. californica became sexually ma- at a rate of 2 liters/min. Rearing temperatures were 13, 15, 18, and ture in the laboratory as well as indices of sexual maturity, such as 21°C. Animal densities were fi ve animals per cage, with fi ve replicate the length of the reproductive period. It has been standard hatchery cages of animals reared at each temperature. One replicate at 13°C practice to maintain a post-metamorphosis rearing temperature of was lost from the experiment at age 317 days due to being shipped 15°C, with the objective to prevent the onset of sexual maturity to researchers. Photoperiod was a 14:10-h light:dark cycle. Animals before 9 months of age. Sexually immature animals provide a more were fed ad libitum daily fresh Gracilaria ferox in exponential growth consistent model in neurophysiological studies and ensure that the phase, after removal of uneaten food from the day before. animals do not approach senescence (13). Comparison of the study of Animals were monitored through maturity to senescence and Kriegstein and colleagues (15) at 22°C with our own studies at 15°C mortality. All animals were inspected each day for mortality, copula- (5, 6, 11) suggested survival and growth of A. californica were highly tion, and the presence of egg masses. Live weight of each animal was temperature-dependent. Th e purpose of this report is to describe determined weekly by using an electronic balance (Mettler, Toledo, growth, sexual maturation, and spawning, and lifespan of laboratory Ohio) after draining excess water from the animal’s parapodial cavity. animals held under diff erent rearing temperatures. Th is was accomplished by holding the animal tail down in air and shaking lightly three times. Sexual maturity for a cage of animals Division of Marine Biology and Fisheries, National Resource for Aplysia, University of was defi ned as the day the fi rst egg mass was laid. Animal densities Miami Rosenstiel School of Marine and Atmospheric Science, 4600 Rickenbacker Causeway, Miami, Florida 33149 were altered after the death of animals, such that from age 226 days, *Corresponding author the day the fi rst animal died, some cages had fewer than fi ve animals Volume 44, No. 3 / May 2005 CONTEMPORARY TOPICS © 2005 by the American Association for Laboratory Animal Science 31 Figure 1. Live weight (mean ± 1 standard deviation) of Aplysia californica with age at each temperature from age 170 days to the death of individual animals. Th e smaller standard deviations for the last several points were caused by reduced sample size due to animal death. Arrow denotes age at which the fi rst egg mass was laid. (A) 13°C. (B) 15°C. (C) 18°C. (D) 21°C. per cage. Th e experiment concluded when the last animal died. An set values, except on one day when temperature in the 13°C cages ° actuarial analysis of mortality data was performed using the survival fell to 10.7 C, a 32% change. Salinity, pH, and O2 concentration program described in Wilson (19), which fi ts the Gompertz survival were also monitored and did not vary signifi cantly from established function to an observed survival curve by nonlinear regression analy- norms for the hatchery (salinity, 35.0 parts per thousand; pH, 8.4; = Gt sis. Th e Gompertz mortality rate function is defi ned as M Ae , O2, 7 mg/liter; 5). where M = mortality rate, A = initial mortality rate, G = Gompertz Th e average growth of A. californica maintained at each experimen- exponential parameter, which is considered the “aging rate,” and t = tal temperature is illustrated in Fig. 1, which shows the sigmoidal time (in days). Th e Gompertz function commonly is used to describe growth typical of this species (5, 11, 15, 18). Temperature strongly the exponential increase in the mortality rate with time that is typical aff ected growth rate, lifespan, and maximum size. Growth rates, de- of aging populations. Th e initial mortality rate, A, is the mortality rived from linear regression fi ts from the fi rst 35 and 90 days of the rate independent of senescence, which can vary between cohorts. G experiment (ages 205 and 260 days, respectively) show that growth is commonly expressed in terms of the mortality rate doubling time rates were highly dependent upon temperature (Table 1). Growth rates (MRDT), a constant, where MRDT = ln 2/G. to age 205 days show the fastest growth rates occurring at 18 and 21°C Statistical tests (analysis of variance [ANOVA], ANOVA with and the slowest growth rate at 13°C. Th e eff ect of temperature on Scheff é post-hoc pairwise comparison, and the Wilcoxen test) were growth was so strong that animal weights were signifi cantly diff erent done using Datadesk 6.2 for Macintosh (Ithaca, N.Y.). α = 0.05. (P ≤ 0.0001) after just 1 week of rearing at the diff erent temperatures. Th is trend continued for the fi rst 5 weeks, to age 205 days, but then Results began to invert. At 6 weeks, or age 212 days, the animals at 13 and ° ≤ Th e temperatures (mean ± 1 standard deviation) over the course 15 C began to gain signifi cantly (P 0.0001) more weight than those of the experiment were 12.7 ± 1.04°C, 14.9 ± 0.831°C, 18.1 ± reared at the two higher temperatures.
Load more

Recommended publications
  • Draft Genome of the Peruvian Scallop Argopecten Purpuratus
    GigaScience, 7, 2018, 1–6 doi: 10.1093/gigascience/giy031 Advance Access Publication Date: 2 April 2018 Data Note DATA NOTE Draft genome of the Peruvian scallop Argopecten Downloaded from https://academic.oup.com/gigascience/article/7/4/giy031/4958978 by guest on 29 September 2021 purpuratus Chao Li1, Xiao Liu2,BoLiu1, Bin Ma3, Fengqiao Liu1, Guilong Liu1, Qiong Shi4 and Chunde Wang 1,* 1Marine Science and Engineering College, Qingdao Agricultural University, Qingdao 266109, China, 2Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China, 3Qingdao Oceanwide BioTech Co., Ltd., Qingdao 266101, China and 4Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China *Correspondence address. Chunde Wang, Marine Science and Engineering College, Qingdao Agricultural University, Qingdao 266109, China. Tel: +8613589227997; E-mail: [email protected] http://orcid.org/0000-0002-6931-7394 Abstract Background: The Peruvian scallop, Argopecten purpuratus, is mainly cultured in southern Chile and Peru was introduced into China in the last century. Unlike other Argopecten scallops, the Peruvian scallop normally has a long life span of up to 7 to 10 years. Therefore, researchers have been using it to develop hybrid vigor. Here, we performed whole genome sequencing, assembly, and gene annotation of the Peruvian scallop, with an important aim to develop genomic resources for genetic breeding in scallops. Findings: A total of 463.19-Gb raw DNA reads were sequenced. A draft genome assembly of 724.78 Mb was generated (accounting for 81.87% of the estimated genome size of 885.29 Mb), with a contig N50 size of 80.11 kb and a scaffold N50 size of 1.02 Mb.
    [Show full text]
  • <I>Aplysia Californica</I>
    Journal of the American Association for Laboratory Animal Science Vol 45, No 1 Copyright 2006 January 2006 by the American Association for Laboratory Animal Science Pages 40–47 Life History and Aging of Captive-Reared California Sea Hares (Aplysia californica) Robert Gerdes and Lynne A. Fieber* Although the California sea hare, Aplysia californica, is well known from neurobiological studies and is raised in the laboratory for this purpose, various aspects of its life history in the laboratory, such as aging dynamics, are unknown. There- fore we collected life history data on 4 cohorts of eggs from hatchery-reared animals and performed an actuarial analysis of mortality data. Temperature was controlled at 13 to 15 °C, the photoperiod was a 14:10-h light:dark cycle, and the seawater O2 concentration, pH, and salinity were held at optimized levels. The feeding protocol for 3 cohorts was unrestricted access to the red macroalga Gracilaria ferox, whereas the remaining cohort was fed standard hatchery rations of G. ferox 4 times per week. Growth was sigmoidal in each cohort and resulted in linear growth rates of 1.25 to 3.62 g/d during the exponential phase; these rates were not influenced by feeding level. Sexual maturity occurred at approximately 160 g, at ages ranging from 144 to 241 d. Egg production was highly variable in the different cohorts. Mean lifespan of cohorts fed ad libitum was approximately 228 d. In contrast, the cohort fed standard rations lived an average of 375 d and showed a lower initial mortality rate, suggesting that calorie restriction on a single-species diet prolongs lifespan in California sea hares.
    [Show full text]
  • An Adipokinetic Hormone Acts As a Volume Regulator in the Intertidal Gastropod Mollusk, Aplysia Californica
    ORIGINAL RESEARCH published: 24 August 2018 doi: 10.3389/fendo.2018.00493 An Adipokinetic Hormone Acts as a Volume Regulator in the Intertidal Gastropod Mollusk, Aplysia californica Anthony W. Martillotti and Pei-San Tsai* Department of Integrative Physiology, University of Colorado, Boulder, CO, United States Adipokinetic hormone (AKH) is a multifunctional neuropeptide in the gonadotropin-releasing hormone superfamily. In insects, AKH acts to mobilize energy stores during times of high energetic demand, but has been shown to have other effects. In lophotrochozoans, the presence and function of AKH are less characterized. We have previously identified an AKH in an intertidal gastropod mollusk, the California sea hare (Aplysia californica), and named it ac-AKH. Our previous data showed ac-AKH induced an acute weight loss, suggesting a role in volume regulation. The overarching goals of this study were to test the role of ac-AKH as a volume regulator and examine the mechanism by which ac-AKH induced the acute weight loss. Our results showed that ac-AKH Edited by: reduced body mass, in part, through the reduction of hemolymph volume without Honoo Satake, Suntory Foundation for Life Sciences, altering hemolymph osmolality or specific osmolytes. The effect of ac-AKH on volume Japan loss was accentuated under a hyposaline condition. We further showed that ac-akh Reviewed by: expression was inhibited during a hyposaline challenge, and that the administration of Fumihiro Morishita, ac-AKH partially reversed the increase in body mass, but not hemolymph osmolality Hiroshima University, Japan Makoto Osada, change, caused by the hyposaline challenge. These data collectively show that ac-AKH Tohoku University, Japan is a proximate regulator controlling the fluid volume, but not osmolality, in A.
    [Show full text]
  • Developmental Transcriptome of Aplysia Californica'
    RESEARCH ARTICLE Developmental Transcriptome of Aplysia californica ANDREAS HEYLAND1Ã, ZER VUE2, CHRISTIAN R. VOOLSTRA2,3, 2 4,5Ã MO´ NICA MEDINA , AND LEONID L. MOROZ 1Integrative Biology, University of Guelph, Ontario, Canada 2University of California, Merced, School of Natural Sciences, Merced, California 3Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia 4The Whitney Laboratory for Marine Bioscience, University of Florida, Florida 5Department of Neuroscience, University of Florida, Florida ABSTRACT Genome-wide transcriptional changes in development provide important insight into mechanisms underlying growth, differentiation, and patterning. However, such large-scale developmental studies have been limited to a few representatives of Ecdysozoans and Chordates. Here, we characterize transcriptomes of embryonic, larval, and metamorphic development in the marine mollusc Aplysia californica and reveal novel molecular components associated with life history transitions. Specifically, we identify more than 20 signal peptides, putative hormones, and transcription factors in association with early development and metamorphic stages—many of which seem to be evolutionarily conserved elements of signal transduction pathways. We also characterize genes related to biomineralization—a critical process of molluscan development. In summary, our experiment provides the first large-scale survey of gene expression in mollusc development, and complements previous studies on the regulatory mechanisms
    [Show full text]
  • The Population Dynamics and Feeding Preferences of Bursatella Leachii (Opisthobranchia: Anaspidea) in Northeast Queensland, Australia
    Records of lite Western Australian il.1H5eWr! Supplement No. 69: 11-21 (2006). The population dynamics and feeding preferences of Bursatella leachii (Opisthobranchia: Anaspidea) in northeast Queensland, Australia Cathryn L. ClaTke James Cook University, Townsville, Queensland 4811, Australia Email: [email protected] A!:-5tr~ct - Sea h",E'5 (OpisthoDranchi<t; Anaspidea) have iong been known to form dense aggregations in shallow marine hahitats Ho'.'!e'.'er, the)·!:' hi?\'e been few attempts to document the dynamics and causes of these i1bg,egations. ThE; present report investigates the population dynamics of Bursatella JeQchii found in assoCiation \·vith a cyanobacterial bloom in tropical north Queensland, Australia. The aggregatIon was fuelled by a continual source of recruits and in laboratory testing, this population preferred a green alga to its prey item in the field, the cyanobactepum, Calothrix crustacea. Therdore, B. Ieachil' has the ability to continually recruit in large numbers to seagrass beds in order to exploit an abundFmt but less preferred food resource. Key words: Bursatella leach ii, Stylocheilus stria/lis, sea hare, Anaspidea, feeding preference INTRODUCTION preference for low~i.ntensity wave action and their The single unifying feature of all populations is preference for intertidal algae species. In one year, their dynamism. Documenting natural population Plaut et aL (1998) observed a rare algal bloom in fluctuation has become increasingly important in deeper water and Aplysia oculi/era was found in recent times where the need exists to distinguish greater abundance in association with this bloom natural fluctuations in systems from those caused than those populations in the exposed shallow­ by anthropogenic disturbance.
    [Show full text]
  • Life History and Aging of Captive-Reared California Sea Hares (Aplysia Californica)
    Journal of the American Association for Laboratory Animal Science Vol 45, No 1 Copyright 2006 January 2006 by the American Association for Laboratory Animal Science Pages 40–47 Life History and Aging of Captive-Reared California Sea Hares (Aplysia californica) Robert Gerdes and Lynne A. Fieber* Although the California sea hare, Aplysia californica, is well known from neurobiological studies and is raised in the laboratory for this purpose, various aspects of its life history in the laboratory, such as aging dynamics, are unknown. There- fore we collected life history data on 4 cohorts of eggs from hatchery-reared animals and performed an actuarial analysis of mortality data. Temperature was controlled at 13 to 15 °C, the photoperiod was a 14:10-h light:dark cycle, and the seawater O2 concentration, pH, and salinity were held at optimized levels. The feeding protocol for 3 cohorts was unrestricted access to the red macroalga Gracilaria ferox, whereas the remaining cohort was fed standard hatchery rations of G. ferox 4 times per week. Growth was sigmoidal in each cohort and resulted in linear growth rates of 1.25 to 3.62 g/d during the exponential phase; these rates were not influenced by feeding level. Sexual maturity occurred at approximately 160 g, at ages ranging from 144 to 241 d. Egg production was highly variable in the different cohorts. Mean lifespan of cohorts fed ad libitum was approximately 228 d. In contrast, the cohort fed standard rations lived an average of 375 d and showed a lower initial mortality rate, suggesting that calorie restriction on a single-species diet prolongs lifespan in California sea hares.
    [Show full text]
  • Rocky Species Descriptions
    Common Southern California Rocky Intertidal Species ANNELIDS Scientific Name Common Name Abbreviation Spirorbis sp. Coiled tube worm SPSP Description: A very small (less than 5 mm long) worm that makes a coiled white tube. Chaetopterus variopedatus Parchment tube worm CHVA Description: A large (up to 400 mm long) worm that creates a paper-like tube around itself for protection. Phragmatopoma californica Sandy tube worm PHCA Description: A solitary worm that builds a sandy tube to live in; They often clump together to form large “sand castles” CNIDARIANS (anemones & corals) Scientific Name Common Name Abbreviation Anthopleura elegantissima Aggregate anemone ANEL Description: Smaller (usually less than 100 mm across), colonial animals.; often cover their bodies with pebbles and shell fragments. Anthopleura xanthogrammica Green anemone ANXA Description: Large (up to 250 mm across), single animals; disk can be white to green in colour. Corynactis californica Strawberry anemone COCL Description: Small (less than 50 mm across), single animals, although they may be found in clumps; disk is often pink or red in colour. Balanophyllia elegans Orange cup coral BAEL Description: Very small (10 to 15 mm across), single animals, although they may be found in clumps; orange or yellowish-orange in colour. CRUSTACEANS BARNACLES: Nonmoving as adults, may be roughly volcano shaped, or hoof shaped and on stalks. Scientific Name Common Name Abbreviation Balanus glandula White acorn barnacle BAGL Description: B. glandula: bigger than C. fissus, up to 15 mm in diameter and 10 mm high; white to grey in colour; cone shaped, with a diamond-shaped operculum; and deeply ridged plates. Megabalanus californicus Red & white barnacle MECA Description: Large, up to 50 mm in diameter and 30 mm in height;plates are red with white lines; finely grooved; has distinct white sections between striped plates.
    [Show full text]
  • Renewable Energy in Situ Power Cable Observation
    Pacific Outer Continental Shelf Region OCS Study BOEM 2016-008 RENEWABLE ENERGY IN SITU POWER CABLE OBSERVATION C A L IFO RN Nearshore I 11–14 m A Area Detailed Pipe HONDO Offshore 76–213 m HERITAGE HARMONY (A) (B) (C) (C1) This page intentionally left blank. ii OCS Study BOEM 2016-008 RENEWABLE ENERGY IN SITU POWER CABLE OBSERVATION Authored by: Milton S. Love Mary M. Nishimoto Scott Clark Ann S. Bull Submitted by: Marine Science Institute University of California Santa Barbara, CA 93106 Prepared under: BOEM Cooperative Agreement No. M11AC00008 The U.S. Department of the Interior Bureau of Ocean Energy Management Pacific OCS Region Camarillo, CA, 93010 April 2016 iii Disclaimer This report was prepared under a cooperative agreement between the Bureau of Ocean Energy Management and the University of California, Santa Barbara. The report has been technically reviewed by BOEM and it has been approved for publication. The opinions, findings, conclusions, or recommendations in this report are those of the authors, and do not necessarily reflect the views and policies of BOEM. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use. Report Availability To download a PDF of this report, go to the U.S. Department of the Interior, Bureau of Ocean Energy Management, Environmental Studies Program Information System (ESPIS) website and search on OCS Study BOEM 2016-008. This report can also be downloaded at www.lovelab.id.ucsb.edu. Citation Love, M. S., M. M. Nishimoto, S. Clark, and A. S. Bull. 2016. Renewable Energy in situ Power Cable Observation.
    [Show full text]
  • Opisthobranchia: Anaspidea) in Northeast Queensland, Australia
    DOI: 10.18195/issn.0313-122x.69.2006.011-021 Records of the Western Australian Museum Supplement No. 69: 11-21 (2006). 'The population dynamics and feeding preferences of Bursatella leachii (Opisthobranchia: Anaspidea) in northeast Queensland, Australia Cathryn L. Clarke James Cook University, Townsville, Queensland 4811, Australia Email: [email protected] Abstract - Sea hares (Opisthobranchia: Anaspidea) have long been known to form dense aggregations in shallow marine habitats. However, there have been few attempts to document the dynamics and causes of these aggregations. The present report investigates the population dynamics of Bursatella leachii found in association with a cyanobacterial bloom in tropical north Queensland, Australia. The aggregation was fuelled by a continual source of recruits and in laboratory testing, this population preferred a green alga to its prey item in the field, the cyanobacterium, Calothrix crustacea. Therefore, B. leachii has the ability to continually recruit in large numbers to seagrass beds in order to exploit an abundant but less preferred food resource. Key words: Bursatella leachii, 5tylocheilus striatus, sea hare, Anaspidea, feeding preference INTRODUCTION preference for low-intensity wave action and their The single unifying feature of all populations is preference for intertidal algae species. In one year, their dynamism. Documenting natural population Plaut et al. (1998) observed a rare algal bloom in fluctuation has become increasingly important in deeper water and Aplysia oculifera was found in recent times where the need exists to distinguish greater abundance in association with this bloom natural fluctuations in systems from those caused than those populations in the exposed shallow- by anthropogenic disturbance.
    [Show full text]
  • Shifts in the Distribution and Abundance of Coastal Marine Species Along the Eastern Pacific Ocean During Marine Heatwaves from 2013 to 2018 Steve I
    Lonhart et al. Marine Biodiversity Records (2019) 12:13 https://doi.org/10.1186/s41200-019-0171-8 RESEARCH Open Access Shifts in the distribution and abundance of coastal marine species along the eastern Pacific Ocean during marine heatwaves from 2013 to 2018 Steve I. Lonhart1* , Rikke Jeppesen2, Rodrigo Beas-Luna3, Jeffrey A. Crooks4 and Julio Lorda3,4 Abstract Background: Ongoing global ocean warming and a recent increase in the frequency and duration of marine heatwaves have demonstrably impacted marine ecosystems. Growing evidence points to both short- and long- term biological changes, across several levels of organization. While range shifts are among the predicted responses, few studies are focused solely on documenting such changes. Here we report ecological changes in response to marine heatwaves across multiple taxa in the eastern Pacific from central California to Baja California. Methods: Sea surface temperature data from two estuaries and one coastal site were analyzed to define the number, duration, and intensity of marine heatwaves occurring in central and southern California from 2013 to 2018. Long-term monitoring programs and short-term research projects in coastal and estuarine ecosystems serendipitously collected specimens or photographs of extralimital species from central California to the Baja California Peninsula. Spatial and temporal sampling protocols and the targeted species for six unrelated programs varied greatly, from annual to monthly at both fixed and variable locations. In addition, anomalous occurrences were reported to staff at local and regional marine and estuarine protected areas and noted in local news and social media outlets. Anomalous range detections were categorized as range expansions and extensions, reappearances, abundance increases, shifts into new habitats, and range contractions.
    [Show full text]
  • The Gill and Siphon Withdrawal Reflex in Aplysia Californica
    The Gill and Siphon Withdrawal Reflex inAplysia californica Eman F. Khwaja Aplysia californica is a principal model organism in the field of neurobiology due to its famously known gill and siphon withdrawal reflex. It was first used in the 1960s by neurobiology researcher Eric Kandel and has since gained popularity due to its easily distinguishable neurons and simple nervous system. Since then, Aplysia californica has been the model organism for research studies across the globe and has contributed to increasing knowledge of ion channels, neurotransmitters, mutations, and learning and memory. The gill and siphon reflex that made this organism popular is a defensive mechanism that results in the gill and siphon of the organism to retract upon exposure to disruptive and threatening stimuli. The unique aspect of this reflex is its synaptic plasticity and learning abilities. The organism can display several types of learning in association with this specific reflex, which include habituations, sensitization, classical conditioning, and operant conditioning. This reflex ofAplysia cali- fornica utilizes a number of aspects of its nervous system and has provided to be extremely influential on studies associated with memory and learning, molecular biology, behavior, genetics, synaptic plasticity, and even aging. plysia californica, more commonly known presence of disrupting stimuli (Moroz, et al., 2006). as the California Sea Hare, is a species of There is a two-step process that occurs when the re- Asea slugs and is part of the phylum Mollus- flex is triggered through a stimulus being applied to ca. Since the 1960s, this Aplysia californica has be- either the siphon or the mantle shelf of the organisms come increasingly popular as a lab model due to the (Moroz, et al., 2006).
    [Show full text]
  • Opportunities in Functional Genomics: a Primer on Lab and Computational Aspects
    Journal of Shellfish Research, Vol. 37, No. 3, 1–8, 2018. OPPORTUNITIES IN FUNCTIONAL GENOMICS: A PRIMER ON LAB AND COMPUTATIONAL ASPECTS STEVEN B. ROBERTS* AND MACKENZIE R. GAVERY School of Aquatic and Fishery Sciences, University of Washington, 1122 NE Boat Street, Seattle, WA 98105 ABSTRACT As computational and sequencing technologies continue to flourish, the barrier for those interested in complementing traditional ecological and physiological studies with functional genomics is easier to overcome. Here, an overview of transcriptome sequencing and DNA methylation analyses in shellfish is provided, primarily for those with fundamental interests and training in a different domain. The approaches covered here can provide valuable information on how organisms respond to their environment and also be used to evaluate evolutionary relationships. First, biological and technological background is provided, highlighting studies in shellfish that have applied these approaches. This is followed by practical methods and tools for conducting this work at the laboratory bench and in front of a computer. In an effort to provide educational resources and the ability to update computational and analytical resources as they become available, a supplementary repository for this work has been created and is available at https://github.com/sr320/fun-gen. KEY WORDS: genomics, bioinformatics, gene expression, DNA methylation, DNA sequencing BACKGROUND latter can easily form a basis for hypotheses that can be tested in later experiments using genomic and nongenomic approaches. When considering marine invertebrates whether in an eco- There are a myriad of processes that can influence transcrip- logical, aquaculture, or culinary perspective, one does not often tional activity, including epigenetic mechanisms.
    [Show full text]