Proboscis musculature in the butterfly Vanessa cardui (Nymphalidae, Lepidoptera): settling the proboscis recoiling controversy

Krenn, H. W. 2000. Proboscis musculature in the butterfly Vanessa cardui (Nymphalidae, Lepidoptera): settling the proboscis recoiling controversy. —Acta Zoologica (Stockholm) 81 : 259–266 The proboscis of Vanessa cardui (Nymphalidae) contains two basal galeal muscles and two different series of numerous oblique muscles. Both muscle series extend from the proximal region up to the tip‐region; the individual muscles of each series run a constant course throughout the proboscis. In contrast to other butterflies, the knee bend region does not have additional types of muscles. The analysis of shock‐frozen proboscises reveals that the dorsal wall is arched outwardly in the uncoiled, feeding position whereas in the coiled, resting position the dorsal proboscis wall is flat or concave. This results in a significantly greater cross‐sectional area due to the significantly greater dorso‐ventral diameter in uncoiled proboscises. After freezing the proboscis in its distal region, it can still be uncoiled, however, it cannot be fully recoiled. These morphometric and experimental results indicate that the oblique proboscis muscles are responsible for recoiling the proboscis to the resting position.     

The röle of the head coelom in proboscis eversion in Arenicola marina (I.)

The dependence of proboscis eversion on the behaviour of the trunk coelom and the effect of increasing the external resistance to eversion have been investigated in Arenicola marina (L.).Two types of proboscis eversion are distinguished; Type I, in which there is an increase of 50–100% in the volume of the head region and where the high pressures recorded in the trunk coelom are needed, it is suggested, to force fluid into the head coelom; Type II, in which the volume change in the head region is small and where simultaneous recordings of head and trunk coelomic pressures indicate that the head coelom can be isolated from the rest of the coelom.Pressures in the trunk are only related to the extent of proboscis eversion when there is a high external resistance to eversion.     

Functional morphology and movements of the proboscis of Lepidoptera (Insecta)

Summary The mouthparts of Lepidoptera were investigated in a number of species by morphological and cinematographical methods. Both the galeae (which compose the proboscis) and the basal maxillary components (stipites) were studied in the resting position, in motion, and during feeding. In the resting position the proboscis is coiled so tightly that the surfaces of the consecutive coils are in close contact and the outermost coil touches the ventral side of the head. Cuticular processes of the galeal wall interlock between the coils in this position. In the investigated species they occur on the galeal wall and on the ventral side of the head in varying number and distribution. By the extension of the basal galeal joint, the coiled proboscis is released from its resting position and is elevated continuously. It uncoils in 3–5 steps which effect the entire length simultaneously. Each uncoiling step occurs synchronously with a compression of the stipital tubes on either side of the body. These compression movements pump hemolymph into the galeae. In all investigated Lepidoptera the uncoiled proboscis shows a distinct downward bend at a certain point which is also detectable in anaesthetized or freshly killed animals in some species. This feeding position and the movements of the uncoiled proboscis are similar in all species despite the intrinsic galeal muscles being variously arranged in the galeal lumen in different Lepidoptera. When comparing cross-sections through corresponding regions of coiled and uncoiled proboscises, the curvatures of the dorsal galeal walls remain unchanged. Coiling of the proboscis starts at the tip and progresses to the base. After coiling the proboscis tightly beneath the head, the diameter of the spiral widens due to its elastic properties until the proboscis props itself against the ventral side of the head. This elastic effect combined with the interlocking cuticular processes seems to be responsible for the resting position of the proboscis.Abbreviations an antenna - bre bend region - ca cardo - ci cibarium - cl clypeus - co complex eye - cp cuticular process - dre distal region - esm external tentoriostipital muscle - fc food canal - fst flat part of the stipes - ga galea - hs horizontal septum - igm intrinsic galeal muscles - ism internal tentoriostipital muscle - la labium - lap labial palpus - lr labrum - mxp maxillary palpus - ne nerve - pi pilifer - pom primary oblique galeal muscles - pr proboscis - pre proximal region - sa salivarium - se sensillum - som secondary oblique galeal muscles - st stipes - stl stipital lamella - te tentorium - tr trachea - tst tubular part of the stipes - vm ventral membrane - vs vertical septum     

New morphological data on the acanthocephalan <Emphasis Type="Italic">Hypoechinorhynchus magellanicus</Emphasis> Szidat, 1950 (Palaeacanthocephala: Arhythmacanthidae)

Hypoechinorhynchus magellanicus Szidat, 1950 (Acanthocephala: Arhythmacanthidae) is redescribed based on specimens collected from a sub-Antarctic notothenioid fish, Champsocephalus esox (Günther). The host was caught in the Beagle Channel (Magellanic sub-region). H. magellanicus has a trunk with an antero-dorsal curvature, a spherical proboscis, spines on the anterior region of the trunk, narrow lemnisci which are considerably longer than the proboscis receptacle, six cement glands and a single vaginal sphincter. The proboscis is armed with 40 hooks, including 15 large hooks with roots and 25 rootless basal spines. The large hooks are arranged in 10 alternate rows of one and two hooks. Each single large hook is followed by two spines, and pairs of large hooks are followed by single spines. Ten single spines are also present at the base of the proboscis between the rows. The eggs have polar prolongations of the middle envelope.     

Assessment of cell proportions during regeneration ofDileptus anser (Ciliata)

Summary Following transection ofDileptus regulation of cell shape and cortical pattern was studied during regeneration in an attempt to understand the interrelations of these two regulation processes. The cell ofDileptus consists of two regions, proboscis and trunk, with the oral structures marking the border between them. The isolated proboscis is able to reorganize into a complete and correctly proportioned organism and the course of this reorganisation has been observed.Correct cell proportions take more than 24h to be established. Three hours after the operation the new border between proboscis and trunk is formed. Initially, the proportions of the cell are far from normal; moreover, they can temporarily change towards a more abnormal state. This indicates that the localisation of the border between the two cell regions and the assessment of final cell proportions are separate phenomena possibly controlled by different mechanisms.     

Acanthocephalus?amini n. sp. (Acanthocephala: Echinorhynchidae) from the freshwater fish Cichlasoma?urophthalmus (Günther) (Cichlidae) in Mexico

Acanthocephalus amini n. sp. (Palaeacanthocephala: Echinorhynchidae) is described from the intestine of Cichlasoma urophthalmus (Günther) (Pisces: Cichlidae) collected in the Río Champotón, a river in Campeche State, Mexico. It is the fourth species of Acanthocephalus Koelreuther, 1771 described from North American freshwater fishes, although two other species are known from South America. The new species is distinguished from other members of Acanthocephalus by features of its trunk, which is small, clavate, slightly expanded medially and bluntly pointed posteriorly. It is further distinguished by having a cylindrical proboscis armed with 13–14 longitudinal rows of 11–12 stout hooks; the apical and medial proboscis hooks are almost uniform in size and shape, decreasing in size towards the base; the posteriormost hooks are smaller, straighter and more slender than the anterior and middle hooks; and the lateral rows of hooks are more widely spaced, forming a conspicuous longitudinal area devoid of hooks. Furthermore, the lemnisci are saccate and shorter than the proboscis receptacle; and the neck is very short with a thick collar of trunk tegument, which encircles the base of proboscis. In males, the testes are in the middle third of trunk, diagonal, spherical and small relative to the body size, and there are six clavate cement glands. In females, the uterus forms a conspicuous, elongate, cylindrical egg reservoir. The new species is most similar to A. alabamensis Amin & Williams, 1983, but can be distinguished by its swollen, clavate trunk, the largest proboscis hooks being present apically and medially, smaller testes, a shorter male reproductive system relative to body size and females with a prominent uterus. They have different hosts and geographical distribution. The new species can be differentiated from Brasacanthus sphoeroides Thatcher, 2001, a similar species in a monotypic echinorhynchid genus, because the latter is larger, has smaller proboscis hooks and its lemnisci are longer than the receptacle.     

Description and pathology of Neoechinorhynchus idahoensis n. sp. (Acanthocephala: Neoechinorhynchidae) in Catostomus columbianus from Idaho.

Neoechinorhynchus idahoensis is described from Catostomus columbianus caught in the Salmon River, Stanley Basin, Idaho. The new species is closest to Neoechinorhynchus venustus Lynch, 1936, but is distinguished from it by its smaller and variably structured eggs, anterio-dorsal trunk hump, bent and posteriorly notched proboscis receptacle, and larger proboscis, proboscis receptacle, and hooks. It is distinguished also from 2 other species of Neoechinorhynchus with proboscis hooks in middle and anterior circles about equally large and from 7 other species having lemnisci greatly unequal in length. Histopathology of host tissue showed limited host response exemplified by epithelial damage and hemorrhaging at point of proboscis attachment with subsequent macrophage and other phagocytic cell migration. The proboscis extended through the host epithelium into the submucosa with limited hemorrhaging at the point of attachment. Unorganized collagenous fibers were present. The lumen of the host intestine was obstructed, and compressed villi were present. The trunk of the worm damaged intestinal epithelium near the crypts, causing localized inflammation. The caryophyllaeid cestode Isoglaridacris calentinei Mackiewicz, 1974, was present in concurrent infections of C. columbianus.     

Cystacanths of Acanthocephala in notothenioid fish from the Beagle Channel (sub-Antarctica)

The morphology of relaxed cystacanths of polymorphid acanthocephalans collected from notothenioid fishes in the Beagle Channel (Magellanic subregion of sub-Antarctica) is described. A parasite of birds, Andracantha baylisi (Zdzitowiecki, 1986), was found in Patagonotothen longipes and Champsocephalus esox. It has: a proboscis 0.82–0.89 mm long; a proboscis hook formula of 16 rows of 9/10–10/11, including 4–5 basal hooks; distal hooks with the longest blades; a fore-trunk not separated from the hind-trunk by a constriction; large somatic spines arranged in two zones separated by a zone of small, loosely dispersed spines; and only the anterior 36–40% of ventral side of the trunk is covered with spines. One male specimen of Corynosoma sp. was found in Patagonotothen tessellata. It differs from A. baylisi in that the distal proboscis hooks are similar in length to the prebasal hooks, it has a smaller proboscis (0.77 mm) and in the distribution of the somatic spines, which are contiguous with the genital spines on the ventral side of the trunk and lack a zone of small spines between zones of larger spines. A parasite of seals and fur seals, Corynosoma evae Zdzitowiecki, 1984, was found in P. longipes and Champsocephalus esox. It has: a proboscis 0.61–0.78 mm long; a proboscis hook formula of 20–22 rows of 12–13, including 3/4–4 basal hooks; prebasal hooks with the longest blades; a trunk divided into fore-trunk and hind-trunk; somatic spines covering the anterior 64–74% of the ventral side of the trunk; genital spines present only in males; and a terminal genital opening in both sexes. Corynosoma beaglense n. sp. was found in Champsocephalus esox. It has: an almost cylindrical proboscis (length 0.52–0.56 mm); a proboscis hook formula of 16 rows of 9/10–10/11, including 4–4/5 basal hooks; distal hooks shorter than the prebasal hooks; a fore-trunk not separated from the hind-trunk by a constriction; somatic spines contiguous with the genital spines on the ventral side of the trunk of the male and covering the entire length of the ventral side of the female trunk, and the presence of genital spines surrounding the terminal genital pore of the male. The definitive host of this species is unknown.     

The burrowing of Priapulus caudatus

An account is given of the way in which Priapulus caudatus burrows in the muddy sea-bed in which it lives. Three phases are distinguishable in the muscular activity which is responsible for locomotion. During the first phase the animal is able to feed and defaecate, during the second the proboscis becomes invaginated, and during the third the animal moves forward. The power for locomotion is provided by contraction of the longitudinal and circular muscles of the body wall, not, as has been suggested previously, by the retractor muscles of the praesoma. Invagination of the proboscis is apparently stimulated by the arrival of a wave of contraction in the body wall musculature, propagated from the trunk.
In general the animal burrows in a way common for soft-bodied animals; the anterior and posterior extremities acting in turn as "terminal" and "penetration" anchors in the substratum. The muscular activities of the larva are limited by the presence of a lorica which encases the trunk, and the animal's powers of movement at this stage are very restricted.     

Morphology of a new deep‐sea acorn worm (class Enteropneusta,phylum Hemichordata): A part‐time demersal drifter with externalized ovaries

Ten individuals of an enteropneust in the family Torquaratoridae were videotaped between 2,900 and 3,500 m in the Eastern Pacific—one drifting a few centimeters above the bottom, two exposed on the substrate, and seven partly burrowed, reflecting a bentho‐pelagic life style. Here, we describe a captured specimen (26 cm living length) as the holotype of Allapasus aurantiacus n. gen., n. sp. The small proboscis is dome‐shaped, and the collar is only slightly wider than deep; both of these body regions are more muscular than in other torquaratorids, which presumably facilitates burrowing. The proboscis complex, in contrast to that of shallow‐living enteropneusts, lacks a pericardial sac and is located relatively posteriorly in the proboscis stalk. The stomochord is separated from the main course of the gut by the intervention of a small, plate‐like proboscis skeleton lacking posterior horns. The most anterior region of the trunk houses the pharynx, in which the pharyngeal skeletal bars are not connected by synapticles. The postpharyngeal trunk comprises three intestinal regions: prehepatic, hepatic (with conspicuous sacculations), and posthepatic. On either side of the worm, a flap of body wall (lateral wing) runs the entire length of the trunk. The two lateral wings can wrap the body so their edges meet in the dorsal midline, although they often gape open along the pharyngeal region. The holotype is a female (presumably the species is gonochoric) with numerous ovaries located in the lateral wings along the pharyngeal region. Each larger ovary contains a single primary oocyte (up to 1,500 μm in diameter) and bulges outwards in an epidermal pouch attached to the rest of the body by a slender stalk. Such externalized ovaries are unprecedented in any animal, and nothing is yet known of their role in the reproductive biology of A. aurantiacus. J. Morphol. 2012. © 2012 Wiley Periodicals, Inc.     

Description and host relationships of Polymorphus spindlatus n. sp. (Acanthocephala: Polymorphidae) from the heron Nycticorax nycticorax in Peru

Polymorphus spindlatus n. sp. is described from the black-crowned night heron, Nycticorax nycticorax, in Lake Titicaca, Peru. It is distinguished from all 27 known species of the subgenus Polymorphus by its spindle-shaped proboscis and its trunk shape, the anterior 2/3 of which is ovoid, tapering into a tubular posterior end. It resembles Polymorphus brevis (=Arhythmorhynchus brevis), which is, however, longer and considerably more slender, and has smaller and more numerous proboscis hooks per row and smaller eggs. It is separated also from Polymorphus swartzi, Polymorphus striatus, Polymorphus contortus, and Polymorphus cincli by its proboscis armature (usually 18 longitudinal rows of 11-13 hooks each), among other characters. Histopathological sections of host tissue show well defined localized damage including hemorrhaging with subsequent phagocyte cell migration (granular tissue). The lumen of the host intestine is obstructed and villi show compression. The proboscis of P. spindlatus extends through the intestinal mucosa and submucosa, displacing the smooth muscle layers of the muscularis externa. Fibrosis also was observed.     

Description and morphological variability of <Emphasis Type="Italic">Neoechinorhynchus beringianus</Emphasis> n. sp. (Acanthocephala: Neoechinorhynchidae) from north-eastern Asia

Neoechinorhynchus beringianus sp. n. is described from Pungitius pungitius L. in north-eastern Russia. Since 1986, when it was first found, it was reported as 'N. pungitius Dechtiar, 1971'. However, this new species differs from the latter in having an egg shell without a prolongation of the fertilisation membrane, a larger proboscis and proboscis hooks, a subterminal position of the female genital pore and a more slender trunk, and it occurs in a different site in the intestine. N. beringianus has a small, stout body with an asymmetrical position of the proboscis, which is located ventrally to and at an angle with the longitudinal axis of the body. The proboscis is wider than long, the hooks are of equal size in each circle but diminish in size posteriorly, whereas the lemnisci are subequal in length. It differs from those species of Neoechinorhynchus Stiles & Hassall, 1905 with somewhat similar characteristics in body length, proboscis size and proportions, proboscis hook lengths, egg size, size-ratio of the cement gland and testes, and the number of giant nuclei in the tegument and lemnisci. In different geographical populations of the new species, the sizes of both the proboscis and proboscis hooks exhibit some variation.     

Description of Pomphorhynchus spindletruncatus n. sp. (Acanthocephala: Pomphorhynchidae) from freshwater fishes in northern Iraq,with the erection of a new pomphorhynchid genus,Pyriproboscis n. g., and keys to genera of the Pomphorhynchidae and the species of Pomphorhynchus Monticelli, 1905

The status of species of Pomphorhynchus Monticelli, 1905 is examined and 23 species are recognised as valid. These include P. spindletruncatus n. sp., which is described herein from two species of freshwater fishes in northern Iraq, Aspius vorax Heckel and Barbus xanthopterus (Heckel) (Cyprinidae). Only one other species, P. yunnanensis Wang, 1981, has a spindle-shaped trunk similar to that of P. spindletruncatus, but is distinguished from it by a distinctly different proboscis armature. A key separating the new taxon from other species of Pomphorhynchus is included. P. heronensis Pichelin, 1997 is reassigned to a new pomphorhynchid genus, Pyriproboscis n. g., based on its unique proboscis shape and armature, short proboscis receptacle and tubular cement glands. A key to the genera of the Pomphorhynchidae is also included.     

Rhinoglena frontalis (Rotifera,Monogononta): a scanning electron microscopic study

Females and males of Rhinoglena frontalis (Monogononta, Epiphanidae) are observed by SEM and their external morphologies are compared. The two sexes differ in size and shape of the body. The female body is fusiform with a short, conical foot, while the male body is more slender and has a rather long foot. The rotatory apparatus (or corona) of both sexes is similar with only minor differences and consists of rows and tufts of cilia arranged around the mouth opening. The corona is made of two paired lobes lateral to the mouth and of a third prominent dorsal lobe, usually called proboscis. The three lobes are lined externally by dense rows of cilia, which constitute the cingulum, used for swimming. The central surface of the proboscis is covered with numerous longitudinal rows of cilia bent towards the mouth. The lateral lobes show, on their central surfaces, two concentric arcs of cirri (made of tightly packed cilia) bent towards the mouth. The similar organization of the rotatory apparatus of both sexes is related to the fact that the male, in this species, is able to feed and has a developed mastax and digestive system. The trophi of both sexes are illustrated and compared.     

A new acanthocephalan family, the Isthmosacanthidae (Acanthocephala: Echinorhynchida), with the description of Isthmosacanthus fitzroyensis n. g., n. sp. from threadfin fishes (Polynemidae) of northern Australia

Isthmosacanthus fitzroyensis n. g., n. sp. is described from two species of protandrous fish, Eleutheronema tetradactylum (Shaw) and Polydactylus macrochir (Günther), from the waters around the coast of northern Australian. The new species can be distinguished from all others by the following combination of characters: proboscis shape and armature (22 rows of 13-14 hooks), short neck, trunk spined anteriorly and having two swellings (one bulbous) with a narrow isthmus in between, long tubular lemnisci and six tubular cement glands. Although I. fitzroyensis has been confused with a species of Pomphorhynchus Monticelli, 1905 in the literature, it can be distinguished from all pomphorhynchids, including species of Longicollum Yamaguti, 1935 and Pyriproboscis Amin, Abdullah & Mhaisen, 2003, by the suite of characters listed above. The placement of the species of Pyriproboscis in the Pomphorhynchidae Yamaguti, 1939 is problematical, because it has a short neck, two distinct hook types comprising the proboscis armature and only two rather than six cement glands. A new family, the Isthmosacanthidae n. fam., is erected to contain Isthmosacanthus together with Gorgorhynchoides Cable & Linderoth, 1963 and Golvanorhynchus Noronha, Fabio & Pinto, 1978, genera having an elongate to clavate proboscis, anterior trunk spines, elongate lemnisci, and six tubular cement glands. The validity of this determination, based on the importance of cement gland number and phylogenetic analysis, is argued.     

STRUCTURE AND AFFINITIES OF PROTOSTIGMARIA EGGERTIANA

Investigation of new, more or less complete specimens of Protostigmaria eggertiana reveals that it is a large, multilobed rooting structure produced at the base of a small arborescent lycopod. The trunk bears scars marking the point of attachment of leaves, and can be compared to the stem of Lepidodendropsis. In the largest specimens the root-bearing base is divided into about 13 lobes. In smaller, presumably younger specimens, fewer lobes are present. The roots are arranged on the lobes in series and orthostichies comparable to those of Isoetes. New observations on five- and six-lobed Isoetes plants reveal a closer correspondence between Protostigmaria and Isoetes than previously recognized; and support suspected homologies among many fossil and extant lycopsid rooting structures.     

On a new acanthocephalan family and a new order, from birds in Vietnam

During November 2000, a collection of acanthocephalans from birds in Quang Ninh Province, Vietnam, included a new genus and species in a new family and order. Pyrirhynchus heterospinus n. gen., n. sp. (Pyrirhynchidae n. fam.: Heteramorphida: new order) is described from Actitis hypoleucos (Linnaeus, 1758) (common sandpiper). The new family combines characters from Polymorphidae and Heteracanthocephalidae, and it includes new features. Specimens of the new species are distinguished from those of Heteracanthocephalidae and/or Polymorphidae by their long cylindrical trunk with anterior swelling, pyriform proboscis with hooks much larger ventrally, brain at the anterior end of the receptacle, specialized tubular cement glands, and elliptoid eggs with concentric shells. A detailed analysis of proboscis and trunk armature is included, and specimens of several species of Arhythmorhynchus Lühe, 1911 (Polymorphidae) were studied for comparative purposes. The proboscis of P. heterospinus is armed with 17 to 20 rows of 17 to 19 hooks each, with anterior 9-11 hooks rooted and posterior 6-10 spines rootless.