Scientific Correspondence

Sousa teuszii (Kükenthal, 1892)

It is incorrectly stated by the authors that Kükenthal (1892) did not provide a figure in his description. He did so—as already quoted by Hershkovitz (1966)—with plate 21 of the volume in question: a photograph of the skull of the specimen (available at http://www.biodiversitylibrary.com). Van Beneden (1892) had drawings made from the photographs Kükenthal had sent him. The assumption that the holotype was in Jena, Germany, had hitherto solely been put forward by Hershkovitz (1966) who obviously had overlooked the correct information contained, e.g., in Fraser (1949) as well as in Cadenat (1956). An inquiry to the Natural History Museum Archive in London provided promptly a postcard by Kükenthal dated 24 July 1893 written in German Sütterlin handwriting to the German-born Albert C. L. G. Guenther announcing the immediate shipment of the skull to London. Turning to an advice in Latin: ad fontes!—Seek the source and do not repeat the error of others. Besides in Pilleri and Gihr (1972), a photograph of the holotype is even found in Jefferson and Van Warebeek (2004).

Sousa chinensis (Osbeck, 1765)

Osbeck (1765) in the German translation of his Swedish diary provided a scientific name and just a single descriptive character of the dolphins he had sighted: their snow-white skin color. Jefferson and Rosenbaum surprisingly quote Linnæus (1758) for “no type specimen was provided” probably extracted from Jefferson and Karczmarski (2001) who wrote: “no type specimen was collected, because this was 1 year before Linnæus' taxonomical system was published in 1758.” Linnæus (1758) could of course not have quoted Osbeck (1765) nor did he quote the original Swedish diary (Osbeck 1757). Further, Linnæus (1758) did not propagate the collection of type specimens. The onset of modern nomenclature indeed is the 10th edition of Linnæus' work Systema Naturæ published in 1758, later set to be 1 January 1758 while the concept of assigning type specimens was introduced about a century later.

Osbeck's scientific name and description in the absence of collected specimens was accepted by later authors (e.g., Demarest 1820) as the scientific name of dolphin species yet to emerge from incognition. The description according to the rules of the ICZN qualifies to make the name available, and the specimens observed will be syntypes. There is no requirement of explicit depository of the name-bearing type for these old descriptions.

Flower (1870) in his description of the skeleton of the first ever specimen known to science also gave full credit to Osbeck. Although Flower's specimen became a reference specimen, nonetheless, by definition it cannot be a holotype. Hershkovitz (1966) presumably therefore did not even quote Flower's paper, whereas Pilleri and Gihr (1972) concurringly stated that there was no type specimen for the species.

Jefferson and Rosenbaum call the Flower specimen a “surrogate for a holotype” which has no nomenclatural value at all. They criticize Porter's (2002) designation of a neotype with reference to Jefferson and Karczmarski (2001) and Jefferson and Van Waerebeek (2004) stating that it “was not accurately described” and suggest “not to use it for taxonomical purposes,” in essence not to use it at all, because it was a subadult specimen and therefore might not exhibit the diagnostic features of an adult specimen. But these points are irrelevant to disqualify Porter's neotype. Name-bearing types including neotypes do not have to be “typical” of a species. “The purpose of a type is purely nomenclatural, i.e., to determine the application of names. Types do not need to be typical in the sense of representing an average of the range of variation of a taxon, nor do they need to be a particular sex or life stage, or even a whole specimen” (quote from the ICZN web page).

But Porter (2002) committed an obvious nomenclatural error in considering the Flower specimen a holotype. Because this particular specimen was destroyed during WW II she further had designated another specimen as “neotype” for it. Had the Flower specimen indeed been a holotype, Porter's designation would stand despite the reservations put forward by Jefferson and Rosenbaum. Since it was not, however, there is no reason—nomenclaturally speaking—to designate a neotype after all. Jefferson and Rosenbaum seem to be in agreement herewith and do not offer a solution to the dilemma whether yet another neotype is needed to distinguish between the different Sousa species.

For the assignment of a neotype certain recommendations and rules of the ICZN have to be followed. Since there never was a chinensis holotype, first of all an exceptional need in terms of taxonomy could favor the assignment of a neotype. In such cases the ICZN code would demand evidence that the neotype is consistent with what is known of the former name bearing types; evidence that the neotype came from as close as practicable to the original type locality; and a statement that the neotype is or has become the property of an institution which can preserve it and make it available for study. The specimen selected by Porter (2002) with only minor reservations meets all these demands. I therefore suggest for nomenclatural purposes and for the sake of stability using it as the neotype of Sousa chinensis.

Turning to the coloration of Sousa chinensis, not all individuals within its range develop a pure white (or pink) body color. In the Gulf of Thailand (see Andersen and Kinze 1999) individuals of equal size and presumed age may show all variations between almost white body coloration and an all gray skin color. Jefferson and Rosenbaum concur with Perrin et al. (1987) that Lesson's 1828 name, Delphinus malayanus, is a nomen nudum, i.e., a “naked” name without descriptive details of a name bearing type. This is incorrect, since Lesson both provided a figure and body measurements of a freshly harpooned specimen. The ashy gray coloration and the total length (192 cm or 5′11″ in French units) of dolphin could match that of a subadult Sousa chinensis, but also several other delphinid species, and therefore best should be considered a nomen dubium, a doubtful name.

In summary, the paper delivers, but seems prepared too hurriedly to allow a meticulous nomenclatural investigation.