Posted: May 16 2014
Nassarius albus (Say, 1826), Variable Nassa; Variable Dog Whelk
I’ve been collecting in Florida for a long, long time and for all that time there has been a group of white (most of the time) Nassarius that created a bit of consternation. Note that Lee (2013) argues that the genus level taxon Uzita H. and A. Adams, 1853 is the proper placement for the ubiquitous and speciose group we’re accustomed to as Nassarius Duméril, 1805. In this presentation I am retaining the use of the more familiar “Nassarius.”
Through the ‘80s and ‘90s Abbott’s (1974) treatment of North American Nassarius dominated. Abbott presented “Nassarius albus (Say, 1826) Variable Nassa” and described it as “this unusually variable species.” He suggested “N. consensus (Ravenel, 1861) is possibly only a form” and specified as synonyms “ambiguus Pulteney, 1799, non Solander, 1766; antillarum Orbigny, 1842;” and others. Abbott did not mention N. paucicostatus (Marrat, 1877), which is also confused as part of this group. Rehder (1981) presented only “Nassarius albus” and made no mention of the “synonymous” names listed by Abbott. (Note: Rehder's description and photo are not N. albus - see slide f below.) Subsequent to Abbott and Rehder workers have given species status to these various taxa, but only Redfern (2001) has presented extensive descriptions, including distinguishing characters, for three of them; namely, N. albus, N. antillarum, and N. paucicostatus. Kaicher (1982) and Lee (1998 and 2009) have also provided tidbits that are helpful in ascertaining observational consistency upon which to draw distinctions.
Except for Kaicher (1974), until Redfern (2001), most publications treated N. albus, the earliest named Western Atlantic Nassarius of this group, as an “unusually variable species,” and did not distinguish it from other similar taxa, although by 1962 (Warmke & Abbott, Caribbean Seashells) had recognized that N. ambiguus (Pulteney, 1799), non Solander (= N. ambigua Montagu, 1803) was a synonym. Because of Say’s inadequate description and the absence of type material, various specimens of what are now considered separate species were presented as N. albus, with these others either treated as synonyms or ignored. Some, recognizing that this group of similar species was ill-defined, and being uncertain, presented specimens close to Say’s description as N. albus of authors non Say. We cannot rely upon the descriptions that accompanied these presentations, since they may be inclusive of characters we now would identify with other species. It was not until Redfern (2001) that a presentation was made that designated a specimen as N. albus with enough descriptive detail and comparative analysis to distinguish it and the similar N. antillarum, N. paucicostatus and “N. ambiguus” (an innominate species I’ve designated N. sp. PR). Redfern’s work provided us a sound basis for identifying and separating these and additional similar species, however until a comprehensive DNA-based analysis is performed, distinct species identified and linked to known type material, neotypes designated for existing species names, and new species identified, if applicable, we will not be able to have the greatest possible confidence in the validity of the group of Florida’s “white” Nassarius.
With this presentation (and those for N. consensus and N. paucicostatus), I am attempting to extract from the original descriptions those few descriptive characters that appear to be unique to each species, also utilize those few works that presented a comparative analysis pointing out unique characters, link them to a consistent protoconch, and separate all my little white Florida Nassarius accordingly. I intend to present N. consensus, N. paucicostatus, N. antillarum, N. albus, and those that do not fit any of these. My preliminary conclusion is that all the little white Florida Nassarius are variations of N. consensus, N. paucicostatus, N. albus or are unnamed, and that N. antillarum does not occur in Florida.
Here is a list of the confused taxa in this group:
N. albus (Say, 1826)
No type or figure. From the context of Say’s presentation, it appears his description is based upon a single shell from the “Southern Coast of East Florida,” which he felt was “in no respect different from specimens brought from the West India Islands,” with which he was apparently familiar.
N. consensus (Ravenel, 1861)
No type or figure
N. antillarum (d’Orbigny, 1847)
d’Orbigny’s description is based upon a group of syntypes. However, Kaicher found that only two specimens in the group truly matched d’Orbigny’s description. One of these two is illustrated in Kaicher card 3232. When De Jong & Coomans (1988) examined the nine syntypes present in BMNH they also found that they all did not match d’Orbigny’s description and, as a result, designated d’Orbigny’s figure as the lectotype
N. ambiguus (Pulteney, 1799)
No type or figure. The shell described was of Mediterranean fauna. (Doubtful that this name should be assigned to a western Atlantic shell.) Shells from western Atlantic assigned this name are either variations of one of the others or an unnamed species. Kaicher (1982) and more recently Lee (personal correspondence) have pointed out that "Buccinum ambiguum Pulteney, 1799 is unavailable under the provisions of the Code since it is a primary junior homonym of B. ambiguum Solander ]in Brander, 1766 (28; fig. 56), an available name applied to a fossil from Hampshire, U.K."
N. paucicostatus (Marrat, 1877)
No known authentic illustrations.
N. albus auct. non Say (Kaicher card 3234) and N. albus of authors non Say
These are the many specimens presented as N. albus but which cannot accurately be assigned this name and may be any of the above or as yet are innominate.
Adjacent is Say’s description of N. albus.
There is little to rely upon in Say’s description to help us separate
N. albus. This description, which appears to be based upon a single shell,
lacks any consideration of within species variability, and virtually every
character described can easily apply to several named and what appears
may be several similar innominate taxa occurring in this region. The
approach I’ve taken is to link the protoconch with other relatable
characters from the original descriptions. This worked well for N.
consensus and N. paucicostatus, but Say’s description gives us very little to
work with. The only real information of use that at least eliminates some
taxa, is his indication that N. albus has filiform (thread-like) spiral cords of
equal size, equally elevated across ribs and interspaces, and that the ribs
apparently have elevated shouldering creating the appearance of a
“deeply indented” suture. Frankly, this does not appear to me to be
sufficient information to distinguish Say’s taxon and in the end we won’t
have resolution until someone somewhat arbitrarily picks one as a
neotype and designates new names for the others that then would not
be albus, consensus, paucicostatus or antillarum. However, at the
moment I have the task of using this minimal information to link to a
specimen(s) described by others that also included protoconch data and,
for my purposes, apply the label N. albus. The first presentation I could
find that distinguished the taxa in this group was Kaicher (1982). Her card
#3139 presents N. albus.
We don’t know how Kaicher decided this specimen was N. albus, but the
specimen illustrated on the left side of her card conforms very well to
Say’s overall description, particularly the spiral cording and elevated
shouldering. The enlargement of the protoconch is of the specimen on
the left and illustrates a smooth, broadly conical protoconch of three
whorls. It is doubtful that the two specimens Kaicher illustrated are
indeed the same taxon and the one on the right side of her card is more
probably N. paucicostatus. Lee (1998) appears to have accepted Kaicher’s
assignment in the curation of his collection of Western Atlantic
Nassariidae, where he describes the protoconch of N. albus as
“polyspiral” with an illustration of a 3-whorled protoconch. Redfern
(2001) reported and provided a detailed description and a good photo
of the protoconch of specimens he considered to be N. albus. Redfern’s
description is brief, and its most troubling aspect is the indication of “a
protoconch of 2.5 convex whorls.” I have asked Colin about this and in
private correspondence he indicated that “Using Leal's (1991) whorl-
counting method, I could certainly stretch the protoconch of that shell
to 3 whorls.” The Leal method is the method I use to count protoconch
whorls (see discussion of Counting Protoconch Whorls). (Note: In Aug
2014 I obtained the specimen illustrated and described by Redfern and
added photos in the below slide presentation clearly showing the
protoconch having 3 - 3⅛ whorls.) Faber (2004) discusses N. albus and
points out the necessity of establishing the identity of this taxon, but
does not present any images and notes only that N. albus has "spiral
ribs strong, crossing the axial ribs" as a potential helpful identifier. So,
relying upon and attempting to be consistent with these authors’ opinions, I am taking the position that those little white Nassarius we find in Florida that generally fit Say’s description (with allowance for within species variability and the variability resulting from dietary, environmental and differing regional genetic and habitat influences) and have a smooth, broadly conical protoconch of three whorls should be included in the taxon N. albus (Say, 1826). While many of Say’s described characters can normally be expected to vary across populations and over geographic areas, the characters taken together that I am relying upon to distinguish this taxon from the others in this group are:
1. Broadly conical protoconch with 3 convex, smooth whorls expanding evenly with each whorl. Nuclear whorl not elevated or tilted.
2. Axial ribs shouldered, but not keeled, with shouldering usually high on the whorl.
3. Thin, but distinct spiral cords over entire shell and elevated as distinctly across the ribs and interspaces. Spiral cords finer and more crowded just below the suture, enlarge somewhat around the periphery, and then diminish somewhat.
4. Columella with numerous weak ridges between the major ridge at the top and groove at the bottom (latter two characters not diagnostic).
Abbott, R. Tucker. 1974 American Seashells, Second Edition, Van Nostrand Reinhold Company.
Brander, G., 1766. Fossilia Hantoniensia collecta, et in Musæo Britannico deposita. London. i-vi + 1-43, plates 1-9.
Faber, M. J. 2004. Marine gastropods from the ABC-islands and other localities. 2. The family Nassariidae (Gastropoda: Buccinoidea). Miscellanea Malacologica 1(1): 7-15, VIII.
Kaicher, S. 1982. Kaicher's Card Catalogue of World-Wide Shells. Pack #31 - Nassariidae Part 1. Privately printed, St. Petersburg FL, 108 cards.
Leal, J.H. 1991. Marine prosobranch gastropods from oceanic islands off Brazil; species composition and biogeography. Universal Book Services, Oeestgest, The Netherlands, 418 pp.
Lee, Harry G. December 1998. Western Atlantic Nassariidae. American Conchologist 26 (4): 18-20.
Lee, Harry G. 2009. Marine Shells of Northeast Florida. Jacksonville Shell Club, Jacksonville, Florida.
Lee, H.G. July 2013. Nassa update: Application of the genus-level taxon Uzita H. and A. Adams , 1853 to a large and ubiquitous group of nassariids (Gastropoda: Buccinoidea). Shell-O-Gram 54(4): 6-7.
Redfern, Colin. 2001. Bahamian Seashells: A Thousand Species from Abaco, Bahamas. Bahamianseashells.com, Inc: Boca Raton, Florida.
Rehder, Harald A. 1981. The Audubon Society Field Guide to North American Seashells. Alfred A. Knopf, New York.
Say, T. 1826. Descriptions of marine shells recently discovered on the coast of the United States. Journal of the Academy of Natural Sciences of Philadelphia 5: 207-221.
Warmke, G. & Abbott, T. 1962. Caribbean Seashells. Livingston Publishing Co., Narberth, PA.
This presentation is very long and has 2 galleries. Be sure to scroll down to view Gallery 2.
Photo live animal courtesy Jaxshells. Found by Ariane Dimitris while SCUBA diving at Lake Worth Lagoon near Peanut Island, Palm Beach Inlet, Palm Beach County, Florida, 2014. Digital image copyright 2014 by Ariane Dimitris.