Ronald A. Campbell

Some Trypanorhynch Cestodes from Hawaiian Fishes, with Descriptions of Four New Species

Examination of teleost and elasmobranch fishes for cestodes from the Pacific Ocean off the Hawaiian Islands resulted in the recovery of 7 species of trypanorhynchs, 4 of which are new. The new species are Pseudogrillotia basipunctata, Pterobothrium hawaiiensis, Prochristianella micracantha, and Nybelinia basimegacantha. Tentacularia coryphaena Bosc 1797, Dasyrhynchus giganteus (Diesing 1859), and Parachristianella monomegacantha Kruse 1959 represent new host and distribution records. The family Pseudogrillotidae Dollfus 1969 is emended.

Notes on tetraphyllidean cestodes from the Atlantic coast of North America, with descriptions of two new species.

The genus Rhinebothrium Linton, 1890 (Tetraphyllidea: Phyllobothriidae) is redefined and considered valid. Rhinebothrium spinicephalum sp. n. and R. lintoni sp. n. are described from the southern stingray, Dasyatis americana Hildebrand and Schroeder. The phyllobothriid, R. maccallumi Linton, 1924, and the oncobothriid, Acanthobothrium tortum (Linton, 1916), are redescribed. Discovery of a hermaphroditic specimen of Dioecotaenia cancellata (Linton, 1890) indicates that the dioecious character of these cestodes is not absolute. Until recently, little has been done to clarify or contribute to the knowledge of the elasmobranch cestode fauna from the western North Atlantic since the work of Linton. Lintons descriptions of helminths of teleost and elasmobranch fishes frequently are too inadequate for accurate identification. Furthermore few of Lintons type specimens are available and, of those that are, many have faded and partially disintegrated. Linton (1890) described the genus Rhinebothrium to accommodate species resembling Echeneibothrium, a genus common to the eastern North Atlantic and Mediterranean Sea, but lacking a myzorhynchus (rostellum). He included four species in this genus. Among Lintons descriptions only two dealt with species of Echeneibothrium. One (E. austrinum Linton, 1924) is considered inadequately described, and the second (E. vernetae; syn. E. variabile Beneden sensu Linton, 1889) was redescribed as a new species by Euzet (1956a). The validity of the genus Rhinebothrium has been questioned by Wardle and McLeod, 1952; Young, 1956; Yamaguti, 1959; and Alexander, 1963; and is considered as synonymous with Echeneibothrium. However, Baer (1961) and Williams (1966) have provided evidence that Rhinebothrium may be distinct from Echeneibothrium. Recent collections of elasmobranch cestodes from the Atlantic Coast and Chesapeake Bay have disclosed two new species of Rhinebothrium and sufficient material to better define the morphology of R. maccallumi Linton, 1924. Cestodes designated as Rhinebothrium cancelReceived for publication 18 September 1969. latum by Linton (1890) were recovered from two cow-nosed rays, Rhinoptera bonasus (Mitchill). Schmidt (1969) examined specimens of this cestode from a single cow-nosed ray and found their morphology unlike that of any other family in the order Tetraphyllidea. Due to the unusual characters of these cestodes, among which Schmidt cites their separate sexes, he designated Dioecotaenia cancellata (Linton, 1890) gen. et comb. n. and proposed the new family Dioecotaeniidae. My recovery of a hermaphroditic specimen of Dioecotaenia indicates that the dioecious character of these cestodes is not absolute. This paper also describes in detail Acanthobothrium tortum (Linton, 1916), an oncobothriid recognized as a member of Acanthobothrium by Southwell (1925) and briefly redescribed by Baer and Euzet (1962). MATERIALS AND METHODS Elasmobranchs were collected during the summers of 1967 and 1968 in Atlantic coastal waters from New Jersey to Chesapeake Bay, Virginia. Through the cooperation of the Virginia Institute of Marine Science, hosts were collected in trawling nets, or with hook and line. Specimens of Acanthobothrium tortum, donated by Dr. R. J. Goldstein, Emory University, were collected at the Cape Haze Marine Laboratory, Sarasota, Florida. Helminths were fixed in situ or removed from the spiral valve, studied alive, and fixed without pressure in alcohol-formol-acetic acid (AFA) at room temperature. Whole mounts were stained with Ehrlichs acid hematoxylin or Mayers paracarmine, cleared in methyl salicylate, and mounted in Permount. Frontal and transverse serial sections were stained in Heidenhains iron hematoxylin and eosin. Drawings were made with the aid of a camera lucida and microprojector. All species were compared with available specimens from the USNM Helminthological Collection. Measurements

A revision of some trypanorhynchs from the western North Atlantic described by Edwin Linton.

The species of trypanorhynchs described by Edwin Linton (18910) as Rhynchobothrium tumidulum and Rhynchobothrium hispidum are assigned to the genus Prochristianella Dollfus 1946. Prochristianella penaei Kruse 1959 is a synonym of R. hispidum. Rhynchobothrium brevispine Linton 1897 is placed in the genus Mecistobothrium Heinz and Dailey 1974. The species Prochristianella hispida (Linton 1890) comb. n., P. tumidula (Linton 1890) comb. n., and Mecistobothrium brevispine (Linton 1897) comb. n. are redescribed. Adults of Parachristianella monomegacantha Kruse 1959 from Dasyatis americana Hildebrand and Schroeder, taken in Chesapeake Bay, Virginia, are described. Edwin Linton, in a series of works spanning about half a century, described many cestodes from fishes in the western North Atlantic. Among his descriptions are numerous trypanorhynchs, many of which he believed to be speies of Rhynchobothrium Rudolphi 1819. Dollfus (1929) examined this genus and found it to consist of a complex of genera, thereby rejecting it. He subsequently made several contributions (1942, 1946) correcting the taxonomy of some of Lintons species but the status of many more remains uncertain and requires clarification. Nine of Lintons species were reclassified by Dollfus and the clarification of four more species of Rhynchobothrium in this paper brings to 13 the number correctly identified to date. A list of those species (Table I), their new combinations, and authors, is appended. In the present paper Prochristianella hispida (Linton 1890) comb. n., Prochristianella tumidula (Linton 1890) comb. n., and Mecistobothrium brevispine (Linton 1897) comb. n., are redescribed. Rhynchobothrium agile Linton 1897 is a synonym of M. brevispine (Linton 1897) comb. n. MATERIALS AND METHODS Elasmobranchs were collected from Atlantic coastal waters during the years 1967 to 1972 from Chesapeake Bay, Virginia, and southern New England. Through the cooperation of the Virginia Institute of Marine Science, local fishermen, or research vessel CORSAIR, hosts were collected in trawling nets, traps, or with hook and line. Helminths were fixed in situ or removed from the spiral valve, studied alive, and fixed without pressure in AFA at room temperature. Whole mounts were stained with Ehrlichs acid hematoxylin or Mayers paracarmine, dehydrated, and mounted according to standard procedures. Some scoleces were cleared in Langerons lactophenol and mounted in glycerin jelly to facilitate study of the tentacles. Type specimens were obtained from the USNM Helminth Collection for comparison. Drawings were made with the aid of a microprojector and photomicrography. Measurements are in micrometers unless otherwise indicated and are expressed as length by width. Prochristianella hispida (Linton 1890) comb. n.

New species of Acanthobothrium (Cestoda: Tetraphyllidea) from Chesapeake Bay, Virginia.

Two new species of Acanthobothrium, A. americanum, and A. lineatum, are described from a new host, Dasyatis americana Hildebrand and Schroeder. Acanthobothrium paulum Linton, 1890, is redescribed and considered a valid species. Additional data and corrections are presented in a redescription of A. brevissime Linton, 1908. The locality record for A. floridensis Goldstein, 1964, is extended to Chesapeake Bay, Virginia. A revised key to the species of Acanthobothrium from the Atlantic Coast of North America is presented. Seven species of Acanthobothrium have been described as endemic to elasmobranch fishes from the western north Atlantic and Gulf of Mexico. To date, six of these species, two of which were redescribed by Goldstein (1964), have been considered taxonomically distinct. A study of elasmobranch parasites from the Chesapeake Bay and Atlantic Coast (data to be presented elsewhere) has provided two new species of Acanthobothrium and sufficient material to better define the morphology of A. brevissime Linton, 1908, and to validate A. paulum Linton, 1890. Additional data on the morphology of A. floridensis Goldstein, 1964, were also obtained. MATERIALS AND METHODS Elasmobranchs referred to in this paper were collected from the southern region of Chesapeake Bay, at the Virginia Institute of Marine Science, during the months of June to August, 1967 and 1968. Hosts were collected in trawling nets, or with hook and line. Collecting sites were limited to the lower bay area in that region extending from the mouth of the York River across Hampton Roads to Cape Charles on the Eastern Shore peninsula (37? N, 76020 W). Tetraphyllideans were fixed in situ or removed from the spiral valve, washed in seawater, studied alive, and fixed without pressure in aceto-formol-alcohol either heated or at room temperature. Whole mounts were stained with Ehrlichs acid hematoxylin, cleared in methyl salicylate, and mounted in Permount. Serial sections, stained in Heidenhains iron hematoxylin and eosin, were studied in frontal, transverse, and sagittal views. Drawings were made with the aid of a camera lucida and microprojector. Descriptive measurements are presented in the manner suggested by Goldstein (1967). All species were compared with available specimens from the USNM Helminth Collection, from the collection of Dr. Robert J. Goldstein, Emory University, and from elasmobranchs collected in the Bay of Naples, Italy. Received for publication 10 December 1968. All measurements are in microns unless otherwise indicated.

Rhinoptericola megacantha gen. et sp. n., Representing a New Family of Trypanorhynch Cestodes from the Cownose Ray, Rhinoptera bonasus (Mitchill 1815)

Rhinoptericola megacantha gen. et sp. n. from the spiral valve of the cownose ray, Rhinoptera bonasus (Mitchill), taken in Chesapeake Bay, Virginia, is described. A new family, Rhinoptericolidae, is erected to accept the species. Distinguishing characteristics of the species include: 4 bothridia; heteroacanthous, heteromorphous, atypical armature; absence of sensory pits; an ovary consisting of 4 lobes but lacking a central isthmus; an ooreceptacle; and a uterus with 2 lateral diverticula at its proximal end. Lack of knowledge of the cestode fauna of the cownose ray, Rhinoptera bonasus (Mitchill), is due in part to the infrequent captures of this host. As Bigelow and Schroeder (1953) have pointed out, Most of the published reports of the presence of the Cow-nosed Rays at one point or another along the United States coast have been based on a few specimens. Only three references deal with the cestode parasites of this ray and the worms have proven to be unusual. Linton (1890, 1897) described species of Rhinebothrium, Rhynchobothrium, Tetrarhynchus, and Tylocephalum from this host in the Woods Hole area. Schmidt (1969) discovered that one of the species, Rhinebothrium cancellatum Linton 1890, was a dioecious tetraphyllidean representing a new family. Examination of trypanorhynchs from this host has revealed another unusual cestode which we allocate to the new family, Rhinoptericolidae, described herein. MATERIALS AND METHODS Cestodes were obtained from the spiral valve of a single adult cownose ray caught in the summer of 1967 on hook and line in Chesapeake Bay, Virginia. Worms were fixed in situ with aceto-formolalcohol (AFA) at room temperature and transferred to 70% ethanol. Whole mounts were stained with Ehrlichs acid hematoxylin, dehydrated, and mounted in Permount. Transverse and frontal sections, cut at 10 to 12 ,im, were stained with Harris hematoxylin and counterstained with eosin. Transparent overlays were made to reconstruct internal anatomy of the segments. Some scolices were cleared in Langerons lactophenol and mounted in glycerin jelly to facilitate study of the tentacles. Hook nomenclature is based on the system proposed by Dollfus (1942). Drawings were made with the aid of a microprojector or television monitor. Descriptive measurements are expressed as length by width and include the mean with the range given in parentheses. All measurements are in micrometers unless otherwise indicated. Rhinoptericolidae fam. n. Diagnosis: Order Trypanorhyncha. Heteroacantha atypica, with 4 well-separated, sessile bothridia whose margins are entirely free from the scolex. Scolex and tentacles long. Rhyncheal apparatus well developed. Strobila acraspedote, apolytic, with many segments. Ovary consisting of separate lobes, central isthmus absent. Ooreceptacle present. Vitellaria continuous, circumcortical. Adults parasitic in spiral valve of elasmobranchs. Type and only genus:

Tetraphyllidean cestodes from western North Atlantic selachians with descriptions of two new species.

Rhinebothrium corymbum sp. n. is described from Dasyatis americana Hildebrand and Schroeder. Rhabdotobothrium anterophallum sp. n. is reported from Mobula hypostoma (Bancroft) representing a new family of hosts (Mobulidae) for tetraphyllideans. Both new species can be distinguished from all others by the number and arrangement of bothridial loculi, position of the genital pore, and testes number and distribution. A new host and additional data are presented for Phoreiobothrium triloculatum Linton, 1901. The validity of Caulobothrium Baer, 1948, and Rhabdotobothrium Euzet, 1953, is discussed.

ABYSSOTREMA PRITCHARDAE GEN. ET SP. N. (DIGENEA: FELLODISTOMIDAE) FROM THE DEEP-SEA FISH, ALEPOCEPHALUS AGASSIZI GOODE AND BEAN 1883

Abyssotrema pritchardae gen. et sp. n. is described from the benthic teleost, Alepocephalus agassizi Goode and Bean 1883 (Alepocephalidae), taken from Hudson Canyon in the western North Atlantic. The new genus is placed in the subfamily Monascinae Dollfus 1947 and relationships among Abyssotrema, Elopsium Fischthal and Thomas 1972, and Monascus Looss 1907 are discussed.

Two new species of Echeneibothrium (Cestoda: Tetraphyllidea) from skates in the western North Atlantic.

Echeneibothrium bathyphilum sp. n. is described from the deep-sea skate, Raja bathyphila Holt and Byrne. Echeneibothrium sobrinum sp. n., a parasite in the spiral intestine of the skates Raja ocellata Mitchill and Raja erinacea Mitchill, is described from Vineyard Sound near Woods Hole, Massachusetts. Additional data are given for E. vernetae Euzet, 1956, from living and fixed specimens obtained from the type host in the type locality. Morphology of the strobilae and bothridia, testes numbers, and cirrus pouch dimensions clearly distinguish the new species from all others.