Donald J. Reish

Bacteria induce settlement and metamorphosis of Janua (Dexiospira) brasiliensis Grube (Polychaeta:Spirprbidae)

Abstract Larvae of the spirorbid Janua (Dexiospira) brasiliensis Grube settle on multi-species microbial films grown in laboratory aquaria. Bacteria appear to be responsible for inducing metamorphosis. Larvae of Janua rarely settled on films of the diatom Nitzchia . The larvae settled on pure culture films of bacteria isolated from the green macroalga Ulva lobata , a common natural substratum for Janua (Dexiospira) brasiliensis . Individual bacterial strains varied in their capacity to induce settlement and metamorphosis. Our data suggest that the metamorphic cue is associated with the surface of selected bacterial species.

The effect of heavy metals on laboratory populations of two polychaetes with comparisons to the water quality conditions and standards in Southern California marine waters

Abstract Polychaetous annelid assays were performed with laboratory inbred cultures of juvenile and adult Neanthes arenaceodentata and Capitella capitata to cadmium, chromium, copper, lead, mercury, and zinc in sea water. Data were presented as 96-h and 28-day LC 50 concentrations. Mercury and copper were the two most toxic with zinc and chromium generally the next most toxic followed by lead and cadmium. The adult stages of both species were more tolerant to these metals than the juveniles. Comparisons of these six metals present in the two large domestic sewage outfalls in Los Angeles County indicate that the amount of copper and zinc present in the effluent exceeds the 28-day LC 50 of these two polychaetes. The results were compared to the water quality standards for discharges in the State of California.

The effect of heavy metals on the survival, reproduction, development, and life cycles for two species of polychaetous annelids☆

Abstract The effects of exposure of six metals on survival and reproduction in two species of polychaetous, Ctenodrilus serratus and Ophryotrocha diadema, possessing short life histories were measured. The suppression of reproduction was generally two orders of magnitude less than the 96 h LC50.

Effects of metals and organic compounds on survival and bioaccumulation in two species of marine gammaridean amphipod, together with a summary of toxicological research on this group

The toxicity and bioaccumulation of arsenic, cadmium, copper, lead, mercury, zinc, DDT, PCB and the water-soluble fraction of diesel fuel to the gammaridean amphipods Corophium insidiosum and Elasmopus bampo were measured. At 96 h exposure C. insidiosum was more sensitive to arsenic, zinc, DDT, PCB and the water-soluble fraction of diesel fuel than E. bampo, whereas E. bampo was more sensitive to cadmium, chromium and copper than C. insidiosum. Over a 20-day period C. insidiosum accumulated greater amounts of chromium, copper, lead and zinc than E. bampo, whereas E. bampo accumulated more cadmium, DDT and PCB than C. insidiosum. The toxicity and bioaccumulation of toxicants to other species of marine gammaridean amphipods are tabulated.

Acute toxicity of cadmium to eight species of marine amphipod and isopod crustaceans from Southern California

Amphipods and isopods are important components of the marine intertidal and subtidal fauna where they are found on or in the substrate or among spaces between larger, attached organisms. However, in spite of their abundance and importance, the use of these two endemic marine groups has been limited in comparison to decapods in marine toxicological research. The purpose of this study was to investigate the effect of a single metallic salt, CdCl/sub 2/, on six species of amphipods and two species of isopods under similar experimental conditions. Cadmium was selected as the toxicant in this comparative study since this metal is an important constituent in municipal wastes discharged into southern California marine waters.

Benthic Invertebrates as Indicators of Marine Pollution: 35 Years of Study

Los Angeles-Long Beach Harbors were a grossly polluted body of water at the time of initiation of benthic invertebrate studies in 1951. Waste discharges included industrial, domestic and storm waters which received little or no treatment. The inner harbor water mass contained little or no dissolved oxygen, but the outer harbor was well oxygenated. Benthic conditions were characterized by four different associations of animals plus an azoic zone. A pollution abatement program was initiated in 1968 and has continued to this day. Waste discharges were either eliminated or diverted to treatment plants. The effects of this abatement program were noted shortly thereafter and had a dramatic effect on the benthic fauna. The azoic and polluted zones were repopulated and are now characterized by a rich, varied benthic fauna. Benthic species known only previously from offshore areas are now resident inhabitants of the outer harbor. The usefulness of benthic monitoring over the past 35 years has demonstrated the rapidity of the improvement of ecological conditions as a result of pollution abatement. Furthermore, the knowledge gained from 35 years of study has provided a valuable data base as future changes in the harbor are contemplated.

THE EFFECT OF PETROLEUM HYDROCARBONS ON THE SURVIVAL AND LIFE HISTORY OF POLYCHAETOUS ANNELIDS

Abstract The toxicity of seawater-soluble fractions of No. 2 fuel oil and South Louisiana crude oil to five species of polychaetous annelids ( Capitella capitata , Cirriformia spirabrancha , Ctenodrilus serratus , Ophryotrocha puerilis , and Ophryotrocha sp.) was determined. The results of these 28-day bioassays indicate a wide variability in sensitivity among the species tested with the two oils. The 28-day LC50 values ranged from 1.4 ppm of initial total hydrocarbons for 0. puerilis exposed to No. 2 fuel oil to 17.8 ppm for C. capitata exposed to South Louisiana crude oil. The water soluble fractions of No. 2 fuel oil were more toxic to all species tested than South Louisiana crude oil. The effects of petrochemicals on reproduction were measured for Ctenodrilus serratus and Ophryotrocha sp. Using the number of offspring produced as a measure of effect, a significant suppression in reproduction was noted at concentrations of 2.2 ppm and 1.3 ppm fuel oil to Ctenodrilus and Ophryotrocha , respectively, and at 9.9 ppm of South Louisiana crude oil for both species. A significant reproductive stimulation, however, was observed for Ophryotrocha sp. exposed to a concentration of 1.9 ppm of South Louisiana crude oil.

Induction of abnormal polychaete larvae by heavy metals

Abstract A little known observation that exposure to sublethal concentrations of detergent cause fatal abnormalities in the second generation of a polychaete has been followed up and similar abnormalities have been observed in the first or second generation of larvae exposed to sublethal concentrations of copper and zinc. Few toxicity tests extend beyond the responses of the exposed individuals. The discovery of a delayed reaction to sublethal concentrations of common contaminants of the sea has unknown but potentially important ecological implications.

Gel-Based and Gel-Free Identification of Proteins and Phosphopeptides during Egg-to-Larva Transition in Polychaete Neanthes arenaceodentata

The polychaete Neanthes arenaceodentata- is cosmopolitan in distribution-, has been used as a laboratory test animal. Life history of this species has several unique features; the female dies after spawning and the male incubates the fertilized eggs through the 21-segmented stage. The larvae leave the tube and commence feeding. Changes in protein abundance and phosphorylation were examined during early development of N. arenaceodentata. A gel-based approach and gel-free enrichment of phosphopeptides coupled with mass spectrometry were used to identify proteins and phosphopeptides in fertilized ova and larval stages. Patterns of proteins and phosphoproteins changed from fertilized ova to larval stages. Twelve proteins occurred in phosphorylated form and nine as stage specific proteins. Cytoskeletal proteins have exhibited differential phosphorylation from ova to larval stages; whereas, other proteins exhibited stage-specific phosphorylation patterns. Ten phosphopeptides were identified that showed phosphorylation sites on serine or threonine residues. Sixty percent of the identified proteins were related to structural reorganization and others with protein synthesis, stress response and attachment. The abundance and distribution of two cytoskeleton proteins were examined further by 2-DE Western blot analysis. This is the first report on changes in protein expression and phosphorylation sites at Thr/Ser in early development of N. arenaceodentata. The 2-DE proteome maps and identified phosphoproteins contributes toward understanding the state of fertilized ova and early larval stages and serves as a basis for further studies on proteomics changes under different developmental conditions in this and other polychaete species.

Experience matters: females use smell to select experienced males for paternal care.

Mate choice and mating preferences often rely on the information content of signals exchanged between potential partners. In species where a females reproduction is the terminal event in life it is to be expected that females choose high quality males and assess males using some honest indicator of male quality. The Nereidid polychaete, Neanthes acuminata, exhibits monogamous pairing and the release of eggs by females terminates her life and larval success relies entirely on a males ability to provide paternal care. As such females should have developed reliable, condition-dependent criteria to choose mates to guarantee survival and care for offspring. We show that females actively chose males experienced in fatherhood over others. In the absence of experienced males dominance, as evident from male-male fights, is utilized for mate selection. The preference for experienced males is not affected by previous social interactions between the individuals. We show that the choice of the partner is based on chemical signals demonstrating a ‘scent of experience’ to females providing evidence for the role of chemical signals in sexual selection for paternal care adding to our understanding of the mechanisms regulating condition-dependent mate choice.