American Malacological Bulletin (AM MALACOL BULL)

Publisher: American Malacological Union

Journal description

The American Malacological Bulletin (AMB), published twice each year, contains peer-reviewed contributed articles and symposium papers. Special Editions of the Bulletin, containing topics of exceptional interest, are published as supplements.

Current impact factor: 0.94

Impact Factor Rankings

2015 Impact Factor Available summer 2016
2014 Impact Factor 0.939
2013 Impact Factor 0.843
2012 Impact Factor 1
2011 Impact Factor 1.219
2010 Impact Factor 0.948
2009 Impact Factor 0.551
2008 Impact Factor 0.375
2007 Impact Factor 0.441
2006 Impact Factor 0.804
2005 Impact Factor 0.29
2004 Impact Factor 0.538
2003 Impact Factor 0.257
2002 Impact Factor 0.467
2001 Impact Factor 1.176
2000 Impact Factor 0.417
1999 Impact Factor 0.32
1998 Impact Factor 0.375
1997 Impact Factor 0.22
1996 Impact Factor 0.4
1995 Impact Factor 0.367
1994 Impact Factor 0.424
1993 Impact Factor 0.355
1992 Impact Factor 0.263

Impact factor over time

Impact factor

Additional details

5-year impact 1.10
Cited half-life 10.00
Immediacy index 0.07
Eigenfactor 0.00
Article influence 0.36
Website American Malacological Bulletin website
Other titles American malacological bulletin
ISSN 0740-2783
OCLC 9753438
Material type Periodical
Document type Journal / Magazine / Newspaper

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: The freshwater gastropod family Pleuroceridae suffers from a disproportionately high number of imperiled species and recent extinctions. As pleurocerid diversity has been lost, so too has our ability to study the biology of these animals. However, many extinct species were deposited in natural history collections before their demise. I extracted radulae from dried tissue left in shells of seven extinct species in three genera (Leptoxis Rafinesque, 1819, Gyrotoma Shuttleworth, 1845, Lithasia Haldeman, 1840) to gain insights into the morphological differences separating species and provide data for future researchers. There were notable intergeneric and interspecific differences in radular morphology such as shape of cusps (e.g., dagger-like vs. blunt) and number of denticles on the rachidian, lateral, and marginal teeth. Interestingly, the degree of radular differences among Leptoxis spp. likely corroborates previous hypotheses that the genus is not a natural group. These data are a resource for future studies and should aid in determining the feeding habits and relationships of extinct pleurocerids.
    American Malacological Bulletin 05/2015; 33(2):1-6. DOI:10.4003/006.033.0202
  • [Show abstract] [Hide abstract]
    ABSTRACT: The anatomies of two species of Neoleptonidae are described. Clearly heterodont with cardinal and lateral hinge teeth, the shell also has an internal, parivincular ligament. Shell form suggests a shallow burrowing mode of life in coarse gravels in coastal waters. The labial palps are small and the intestine short further suggesting deposit feeding in well-sorted gravels. A pronounced prodissoconch (II) with a marginal ridge argues for lecithotrophic development further facilitating re-colonization of a narrow niche. In most anatomical respects, the two species are simplified with conjoined inhalant and pedal apertures and few posterior sensory mantle papillae. The ctenidia comprise subequal demibranchs with the outer reduced and the inner modified for internally fertilized embryo brooding. The attachment of each embryo chord to the demibranch filaments is probably from secretions produced by basal glands developed on their abrofrontal surfaces. There may also be secondary external pallial brooding, accounting for the ridged prodissoconch II with attachment achieved via secretions from oil glands in the mantle margin. Comparisons are made with representatives of the earliest-considered affiliates of the Cyamioidea, that is, the Arcticoidea [now rejected], the confamilial Gaimardiidae and Cyamiidae, and the recently suggested Ungulinidae. It is considered that although neoteny has been proposed for the Turtoniidae, Sportellidae, and Neleptonidae to explain cyamioidean small size, anatomical features of the studied species of the latter family herein investigated suggest, rather, that they are simply ‘small’ there being, contrary to the conclusions of others, little evidence of paedomorphosis. In this scenario, smallness is not a reflection of neoteny. It is the evolutionary selection of a life history trait and opted recipe for success. Notwithstanding, earlier suggestions of an affiliation with the Veneroidea are considered plausible, although no reason is seen for not retaining the superfamily Cyamioidea nor its, as contemporaneously recognized, families, including the Neoleptonidae.
    American Malacological Bulletin 03/2015; 33(1):1-21. DOI:10.4003/006.033.0106
  • [Show abstract] [Hide abstract]
    ABSTRACT: Here I present notes on two new species recently found in the upper freshwater portion of the Hudson River, Floridobia winkleyi (Pilsbry, 1912) and Valvata lewisi (Currier, 1868) collected during a study in 2008 (Coote and Strayer 2009, Strayer et al. in prep). Floridobia winkleyi is not only a new record for the river but its presence represents a significant expansion of its limited range from Connecticut to Maine (Smith 1994) and brings into question previously identified specimens attributed to Marstonia lustrica (Pilsbry, 1890) in the river. The other new record is the New York state listed species Valvata lewisi. All species found during the 2008 survey are reported here as well.
    American Malacological Bulletin 03/2015; 33(1):114-117. DOI:10.4003/006.033.0104
  • [Show abstract] [Hide abstract]
    ABSTRACT: Sex-change (protandry or protogyny) has gone unnoticed in many bivalves due to the rapid occurrence of this process. In this paper, histological evidence and analyses of the size structure of three geographically separated populations on the northwestern coast of Mexico together with theoretical considerations strongly suggest that Atrina maura (Sowerby I, 1835) is a protandric species. The gonads of a total of 931 A. maura specimens collected in the three study sites were analyzed: Ojo de Liebre lagoon (27 degrees 55'N, 114 degrees 20'W from March 2002 through February 2003), Ensenada de La Paz (24 degrees 11'N, 110 degrees 26'W, from May 2004 through June 2005 and during 2007), and Bahia Magdalena (24 degrees 30'N, 111 degrees 48'W, from March through October 2008). Microscopic analysis of gonads of hermaphrodite specimens enabled the reconstruction of a detailed histological sequence during the male-to-female transition. Analysis of the sex ratio by size class revealed that males occur primarily in the smaller classes, females in the larger classes and hermaphrodites in intermediate size classes. All the evidence substantiate the hypothesis that this species is not gonochoric.
    American Malacological Bulletin 03/2015; 33(1):43-51. DOI:10.4003/006.033.0102
  • [Show abstract] [Hide abstract]
    ABSTRACT: Dosidicus gigas (d'Orbigny, 1835) is a large, active squid that undergoes a diel vertical migration in the Eastern Tropical and Temperate Pacific. It is a voracious predator on zooplankton and micronekton and supports a large fishery. It is further preyed upon by large vertebrate predators, including whales. Its horizontal distribution is closely tied to productive upwelling regions that are characterized by strong oxygen minimum zones (OMZs). The apparent association with extreme hypoxia is surprising given its large size and high oxygen demand. As part of its daily vertical migration, D. gigas experiences daily temperature changes of 15-20°C, oxygen partial pressures ranging from near anoxia (< 0.8 kPa) to air-saturation (21 kPa) and pH changes from ∼8.1 to < 7.6 at depth. Oxygen minimum zones are believed to be expanding due to climate change, with minimum oxygen levels in the core of the OMZ declining and the low oxygen horizon shoaling. Simultaneously, surface waters are becoming more acidic and temperatures are rising. Here I review the extensive studies of this species that have been conducted over the past decade. D. gigas has a high affinity respiratory protein in the blood that supports a low critical oxygen partial pressure (3.8 kPa at 20 °C) and aerobic survival at night in the upper 200 meters of the water column. A pronounced pH- and temperature sensitivity of oxygen binding promotes oxygen transport across a depth range and in support of high rates of oxygen utilization but may impose constraints on high-temperature and CO2 tolerance. At its deeper, colder daytime habitat depth, D. gigas undergoes a pronounced metabolic suppression. Reduced activity levels and an apparent suspension of transcription and translation contribute to a ∼80% reduction in oxygen demand under 1% oxygen (0.8 kPa at 10 °C). Anaerobic metabolic pathways contribute some energy under these conditions. This metabolic suppression likely limits feeding at depth. Sub-critical oxygen levels, rather than temperature, predator avoidance or prey availability, appear to set the daytime depth distribution. Thus, expanding oxygen minimum zones will alter the daytime depth of peak abundance for these squids while ocean acidification and warming may impose a shallow ceiling above which squid performance is limited. The role of climate change in setting the vertical and horizontal distribution of the species is discussed.
    American Malacological Bulletin 03/2015; 33(1):161-173. DOI:10.4003/006.033.0113