Field Of Spines Research Articles

Polymorphus arctocephali Smales, 1986, a synonym of Corynosoma cetaceum Johnston & Best, 1942 (Acanthocephala: Polymorphidae).

Polymorphus arctocephali (Acanthocephala: Polymorphidae) was differentiated from P. cetaceum based on patterns in the trunk spine distribution and slight morphometric differences. The comparison of both species involved samples from South Australia and did not include P. cetaceum from South America. In this paper we re-examine the systematic position of P. arctocephali based on a more detailed morphological and geographical analysis. Results indicate that P. arctocephali does not differ in trunk spine distribution with respect to P. cetaceum, and that its morphometric differences can be subsumed under the natural variation found within P. cetaceum populations. Therefore, P. arctocephali becomes a junior synonym of P. cetaceum. P. cetacueum was transferred from Corynosoma to Polymorphus due to the absence of genital spines in both sexes. However, adopting the less restrictive definition of genital spines used by several authors, females of P. cetaceum could be considered as bearing genital spines. Species of the genus Andracantha also have genital spines, but specimens of P. cetaceum possess a continuous field of trunk spines, which precludes the assignment of this species to Andracantha. Other generic level characters, as well as ecological data, support clearly the transference of P. cetaceum back to Corynosoma. Therefore, this species becomes Corynmosoma cetaceum Johnston & Best, 1942.

Ovulation induction and gamete transport in the female tract of the musk shrew, Suncus murinus.

The musk shrew Suncus murinus was studied with regard to induction of ovulation, the genesis and role of the vaginal copulation plug, and the behaviour of gametes and embryos within the Fallopian tube. Ovulation occurred about 15 h after ejaculation, which required a mean of 5.2 (range 2-10) intromittent thrusts. Since ovulation occurred also after five thrusts without ejaculation, and after ejaculation without plug formation or sperm deposition, the primary stimulus for this seemed to be the thrust of the penis, the glans of which was covered by a dense field of spines. Neither vasectomized nor prostatectomized males formed a plug at ejaculation, and in the latter case the mean number of spermatozoa reaching the isthmus of the Fallopian tube, the number at the ampullary fertilization site and the rate of fertilisation were lower than in females mated to normal males. Thus both the vesicular gland on the vas deferens and the prostate are essential for formation of the copulation plug, which appears to enhance sperm transport within the female tract. At ejaculation, < or = 10(6) spermatozoa were incarcerated by the plug in the anterior vagina for 6-7 h, by which time a maximal population of several hundred had become established in posterior crypts of the isthmus of the Fallopian tube as small groups of free languidly moving spermatozoa. It remains to be established whether oviductal crypts in this and other shrews have a storage function for spermatozoa or sequester spermatozoa and so regulate the number that reach the fertilization site. Very few spermatozoa reached the ampulla of Suncus. Generally, only one or two spermatozoa had reached the ampulla by 4-5 h, and often less than ten had done so by 5-13 h after ovulation. As a probable correlate, few eggs were penetrated during the first 5 h, with a frequent delay of 10-13 h before most eggs were fertilized. Thereafter, unfertilized eggs were transported through the oviduct at the same rate as developing embryos, which entered the uterus about 85 h after ovulation at the 32-cell stage. There were highly significant differences between the larger KAT/SK strains and smaller OK strain with regard to Fallopian tube length (mean 6.9 mm versus 9.7 mm), as well as the rates of hCG-induced ovulation (5.6 versus 3.25) and of unilateral ovulation (6% versus 50%).

Andracantha tunitae (Acanthocephala) in the Shag (Phalacrocorax aristotelis) from Shetland, Scotland

Following the wreck of the oil tanker Braer on the coast of Shetland, Scotland, in January 1993, many shags (Phalacrocorax aristotelis) were killed. Sixty-nine per cent of these birds were found to harbor a sexually mature acanthocephalan (5 +/- 4.3 [SE] worms per infected bird) in their small intestines. The acanthocephalan has been identified as Andracantha tunitae (= Corynosoma tunitae) on the basis of its characteristic fields of trunk spines and their distribution in the region of the genital aperture.

Andracantha, a New Genus of Acanthocephala (Polymorphidae) from Fish-Eating Birds, with Descriptions of Three Species

Problems in taxonomy of the Polymorphidae are discussed, with particular reference to trunk spines. Andracantha gen. n. is proposed for species with genital spines and 2 fields of trunk spines. Corynosoma gravida Alegret 1941, C. mergi Lundstroöm 1941 and C. phalacrocoracis Yamaguti 1939 are redescribed and placed in Andracantha, with A. gravida (Alegret, 1941) comb. n. designated as type species.

Resurrection of Southwellina Witenberg, 1932, with a Description of Southwellina dimorpha sp. n., and a Key to Genera in Polymorphidae (Acanthocephala)

The family Polymorphidae is briefly discussed, and a key to its genera is presented. The subfamilies Polymorphinae Meyer, 1931, and Corynosomatinae Petrochenko, 1956, are suppressed. Southwellina Witenberg, 1932, is considered valid and is redefined. It contains S. hispida (Van Cleave, 1925), S. macracanthus (Ward et Winter, 1952) comb. n., and S. dimorpha sp. n. The new species was found as juveniles in crayfish, Procambarus clarkii, in Louisiana, and as adults in white ibis, Eudocimus albus, in Florida. It differs from other species in its sexual dimorphism, the female having large hooks and 1 field of trunk spines, and the male having smaller hooks and 2 fields of trunk spines. The following species are considered synonyms of S. hispida: Arhythmorhynchus duocinctus Chandler, 1935; A. fuscus Harada, 1939; Polymorphus ardeae Belopolskaia, 1958; and Hemiechinosoma ponticum Petrochenko et Smogorjevskaia, 1962. Skrjabinorhynchus Petrochenko, 1956, is suppressed and its species are recombined as Arhythmorhynchus capellae (Yamaguti, 1935) comb. n., and Arhythmorhynchus eroliae (Yamaguti, 1939) comb. n. The resulting homonym, A. capellae Schmidt, 1963, is renamed Arhythmorhynchus jeffreyi nom. n. The family Polymorphidae Meyer, 1931, is a homogeneous assemblage of species, most of which are parasites of aquatic birds and mammals. Distinction between species is usually difficult, and between genera even more so. When first proposed, most genera were based on one or a few species. Each genus had some distinctive characteristics which readily separated it from other genera. But as more species were discovered, differences between genera became less apparent; today very slight distinctions are used to separate them. For example, Corynosoma differs from Polymorphus only in possessing genital spines, and in some species the spines are on only one sex. Efforts by Petrochenko (1956) and Yamaguti (1963) to divide the family into the subfamilies Polymorphinae Meyer, 1931, and Corynosomatinae Petrochenko, 1956, resulted in placing genera as obviously closely related as Polymorphus and Corynosoma in different subfamilies. As this is less than useful, I cannot accept these subfamilies as valid. The discovery of a new species in this family has stimulated me to review the status of these related genera. It could be logically argued that all species in this family belong to a single genus. On the basis of similarity of form, embryology, and biology they are obviously genetically similar. However, for a Received for publication 13 October 1972. classification to be workable it must help distinguish between species groups in the most convenient manner possible. Therefore, I have taken a more liberal approach and recognize nin genera, which can be diagnosed by the following key. Key to genera in Polymorphidae Meyer, 1931 (Syn. Filicollidae Petrochenko, 1956) la. Cement glands kidney-shaped. Proboscis of adult female greatly swollen, with hooks restricted to short, radially arranged rows on anterior surface. Parasites of water birds Filicollis Liihe, 1911 lb. Cement glands claviform or tubular. Proboscis swollen or not; when swollen, longitudinal rows of hooks cover entire proboscis 2 2a. Genital spines present on at least one sex. Parasites of aquatic birds and mammals --.---... ---Corynosoma Liihe, 1904 (Syn. Chentrosoma Monticelli, 1905, nec Porta, 1906; Echinosoma Porta, 1907, partim.) 2b. Gental spines absent on both sexes ----3 3a. Anterior end of trunk greatly swollen, separated from rest of trunk by conspicuous constriction 4 3b. Anterior trunk not separated from posterior portion by narrow constriction 5 4a. Anterior trunk with 1 field of spines surrounding it. Parasites of Cetacea .....--Bolbosoma Porta, 1908 (Syn. Echinorhynchus Zoega in Miiller, 1776, partim; Bolborhynchus Porta, 1906.)

Arhythmorhynchus capellae sp. n. (Polymorphidae: Acanthocephala), a Parasite of the Common Snipe Capella gallinago delicata

Arhythmorhynchus capellae sp. n. is described. The description is based on seven males and seven females from the Common Snipe in northern Colorado. The species is contrasted with two similar species, A. comptus Van Cleave and Rausch, 1950 and A. eroliae (Yamaguti, 1939) Van Cleave and Rausch, 1950. It differs from the former in having 14 proboscis hooks per row rather than eight or nine, and from the latter in having no bursal rays and 16 rows of 14 hooks rather than 18 rows of 12 to 13 hooks. This species is described from 14 specimens, seven males and seven females, recovered from the small intestines and ceca of six Common Snipe Capella gallinago delicata taken between January 1961 and March 1962 in northeastern Colorado. All measurements are in microns unless otherwise indicated. Arhythmorhynchus capellae sp. n. Description: Bright yellow and wrinkled when removed from gut. Trunk long and narrow with slight inflation at anterior end. Proboscis nearly cylindrical, armed with 16 longitudinal rows of 14 hooks each, 50 long and not appreciably heavier midventrally; the first three and last four hooks in each row more delicate, measuring 42 to 45 long. Neck about 350 long. Body spines extend about 1.74 mm posterior from neck, less numerous toward rear; length 30 to 35. Subcuticular nuclei restricted to narrow band at swollen area of trunk. Male: Length 12 to 41 mm (35 mm); diameter at midpoint of body 222 to 666 (494). Proboscis length 610 to 721 (653); width 144 to 200 (166). Armature same in male and female. Two testes contiguous, each about 1.43 mm long, located 1.10 to 1.30 mm behind field of body spines. Two tubular cement glands extend from area immeReceived for publication 17 September 1962. * Part of a thesis submitted to the Graduate School of Colorado State University in partial fulfillment of the requirements for the degree of Master of Science, March 1962, under the direction of Dr. O. W. Olsen. This investigaiton was in part supported by a training grant [PHS-2E-94 (cl)] from the Institute of Allergy and Infectious Diseases of the National Institutes of Health, U. S. Public Health Service. diately behind posterior testis and join common sperm duct posterior to Saefftigen's pouch.