The Polychaetous Annelids of the Marshall Islands

Volume: 22Start Page: 208End Page: 23

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 female's 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 male's 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

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

Comparison of the Polychaetous Annelids Populations on Suspended Test Panels in Los Angeles Harbor in 1950-1951 with the Populations in 2013-2014

A 14-month study was conducted of the polychaetous annelids present on attached wooden blocks replaced monthly and quarterly at nine stations in Los Angeles Harbor in 2013-2014 and compared to the results conducted at the same stations in 1950-1951. Many environmental changes have occurred in the harbors over the past 63 years. The harbor has been expanded into the outer harbor, channels have been deepened and pollution abatement programs initiated. The water quality has been improved as a result of these changes especially in the inner harbor area where the dissolved oxygen in the water was low or absent in 1950-1951 and was over 6.0 mg/L in 2013-2014. The number of polychaetes species in these two studies increased from 23 to 64. The serpulid Hydroides elegans was a dominate species in both studies but the pollution indicator Capitella capitata, common in the earlier study, was rare in the recent study. There was a seasonal occurrence in both the number of species and specimens with the highs in the warmer months and lows during December through March in both studies

Comparison of the Marine Wood Borer Populations in Los Angeles Harbor in 1950-1951 with the Same Populations in 2013-2014

A 14 month study was conducted of the marine wood borers present on monthly suspended wooden blocks at nine stations in Los Angeles Harbor in 2013-2014, and compared to the results of a marine borer study conducted in 1950-1951. Many environmental changes have occurred in the harbor over the past 60+ years. The harbor land mass of the outer harbor has been expanded towards the breakwater, channels were deepened, and the water quality improved as a result of pollution abatement. Existing pilings were removed, replaced or covered with two layers of polyethylene. The isopod Limnoria tripunctata and the pelecypod Lyrodus pedicellatus were the principal species and present at nearly all stations. Station C located in the Consolidated Slip area of the inner harbor was the site of 87 and 58 percent of the Limnoria and Lyrodus, respectively, counted during the study. Neither of these species was present at this station in 1950-1951. The dissolved oxygen concentration at this station improved from a mean of 0.1 ppm in 1950-1951 to a mean of 6.7 in 2013-2014 as a result of improved environmental conditions. Larval settlement at Station D numbered in the thousands in 1950-1951 but only 22 were counted during the 2013-2014 survey. This difference was attributed to the effect of piling covering or removal. It is recommended that existing creosoted pilings be covered or removed in the inner harbor area since this was the region of greatest occurrence of wood borers in 2013-2014

The Marine Nature of Nuwuk Lake and Small Ponds of the Peninsula of Point Barrow Alaska

Discusses a score or more ponds, some transient, some persistent, on this narrow gravel spit, their location, nature, salinity and temperature; their biotas, marine and fresh-water, are outlined. Nuwuk Lake, the largest water body of the locality, approx. 600 ft long, max. depth 18.5 ft, is treated in some detail: its bottom, its formation by converging currents of the Bering and Chukchi Seas, ice conditions, temperature, salinity and O2-content. The biotas: euryhaline, reduced shallow-sea fauna are dealt with and the organisms collected during 1952-1960 are tabulated. Comparison is made with the few halocline lakes known in northern Russia and Scandinavia, notably Mogil'noye on Kil'din Island

Redescription of Typosyllis aciculata

5 p. : ill. ; 24 cm.Includes bibliographical references (p. 5)

A New Species of Polychaetous Annelid (Family Capitellidae) from Southern California

Volume: 13Start Page: 78End Page: 8