Somatic musculature of rotifers <Emphasis Type="Italic">Asplanchna girodi</Emphasis> Guerne, 1888 and <Emphasis Type="Italic">Trichotria pocillum</Emphasis> (Müller, 1776) (Rotifera,Pseudotrrocha, Ploima): Comparative aspect

Comparative study of somatic musculature in illoricate rotifer Asplanchina girodi Guerne, 1888 and loricate Trichotria pocillum (Müller, 1776) has been carried out by the method of phalloidin fluorescence and confocal laser scanning microscopy. Similar layering of muscles is revealed, while significant differences are observed in other aspects. Postcoronal transverse muscle of A. girodi and the dorsal portion of the anterior circular muscle of T. pocillum serve as attachment sites for the refractor muscles. All retractors are formed by smooth muscles or striated muscles, except the lateral retractors of A. girodi, which are formed by the most powerful oblique muscles. In A. girodi there are three pairs of retractors, ten longitudinal muscles, and five circular muscles, with a thick muscular plexus connecting them. In T. pocillum there are four pairs of retractors, five transverse muscles, strong foot retractors, and an arched structure of the head region (new for rotifers). Eight pairs of dorsoventral muscles, as identified in T. pocillum, are completely absent in A. girodi.     

The musculoskeletal system of male genitalia in <Emphasis Type="Italic">Curetis bulis</Emphasis> Westwood, 1851 (Lepidoptera,Lycaenidae: Curetinae) and <Emphasis Type="Italic">Paralaxita damajanti</Emphasis> (C. Felder et R. Felder, 1860) (Lepidoptera,Riodinidae: Nemeobiinae)

The muscles of the male genitalia were studied for the first time in two species endemic to the Oriental zoogeographical region, namely Curetis bulis from the subfamily Curetinae (Lycaenidae) and Paralaxita damajanti from the tribe Abisarini (Riodinidae). Both taxa possess a common plan of musculature reflected in the positions of muscles m1, m2(10), m5(7), m7(6), m21, and m28. Two new autapomorphies of Curetis bulis were discovered: the splitting of m4 into two muscles and a shift of the attachment site of one of these muscles onto the dorsal area of the anellus. Apomorphic differences in the position of the genital muscles were found between Paralaxita damajanti and the previously studied Polycaena tamerlana from the family Riodinidae. A new synapomorphy between the latter two species, namely splitting of the aedeagus protractors m6(5), was also found.     

Review of the <Emphasis Type="Italic">Chromis xanthura</Emphasis> species group (Perciformes: Pomacentridae), with description of a new species

A taxonomic review of the Chromis xanthura species group, defined here as having 13 dorsal-fin spines, three upper and three lower procurrent caudal-fin rays, two black bands at the preopercular and opercular margins, and a yellow caudal fin when juvenile, resulted in the recognition of three species, Chromis xanthura (Bleeker 1854), Chromis opercularis (Günther 1867), and Chromis anadema sp. nov. Chromis xanthura and C. opercularis, the Pacific and Indian Ocean paired sister species, respectively, are redescribed, with confirmation of two color types of C. xanthura (having a white or black caudal peduncle and fin) as a single species on the basis of morphological and molecular analyses. Chromis anadema sp. nov., described from the oceanic islands of the Pacific Ocean on the basis of 21 specimens, is characterized by having 28–33 gill rakers; longest dorsal-fin soft ray length 20.0–24.7% of standard length (SL); first anal-fin spine length 5.0–6.1% of SL; caudal-fin length 33.4–43.8% of SL; posterior tips of caudal-fin lobes not filamentous in adults; broad black bands along preopercular and opercular margins, sum width of two bands 28.9–38.7% of head length; distal half of soft-rayed portion of dorsal fin transparent in adults; triangular black blotches at upper and lower caudal-fin base in adults; caudal peduncle and fin bluish black in adults; and body grayish, and all fins (except for pectoral fin) bright yellow in juveniles.     

Muscle development in the Japanese flounder,Paralichthys olivaceus,with special reference to some of the larval‐specific muscles

We investigated muscle development in the Japanese flounder Paralichthys olivaceus, focusing primarily on the cranial muscles, using a whole mount immunohistochemical staining method. It is well established that during the very early stages of morphogenesis, until 4 days post hatching (dph), muscles required for feeding develop. Later, between 8 and 16 dph, the muscle composition in the dorsal branchial arches changes to the adult form. We discovered the presence of larval‐specific muscles in this ontogenetic period, termed the larval branchial levators 2 and 3, located in the dorsal branchial arches. The larval branchial levators 2 and 3 disappear during the course of development, whereas the others remain as levator internus 1 and levator posterior, which have also been described in adult fish. In place of these regressed muscles, the levatores externi and levator internus 2 develop and regulate the branchial arches. In addition, we found that the levator posterior, which is thought to represent the fifth levator externus, and the levatores externi exhibit different origins. We also found that at least a part of the caudal fin musculature develops from the trunk myotome. J. Morphol. 2010. © 2010 Wiley‐Liss, Inc.     

New species of eel cods <Emphasis Type="Italic">Muraenolepis pacifica</Emphasis> sp. nova (Muraenolepididae) from the ridge of hercules (Pacific-Antarctic Ridge)

The new species of moray cod Muraenolepis pacifica sp. nova from the Pacific ocean, i.e., the Hercules and Umanov banks (Pacific-Antarctic Rise) from the depths of 200–500 m is described. The new species closely resembles M. orangiensis, but it reliably differs from the latter by the shorter caudal part of the body, more caudal position of the insertions of dorsal and pectoral fins, longer upper jaw, and other proportions of the body. The new data about holotype M. orangiensis obtained in its X-ray study are given.     

The osteology of <Emphasis Type="Italic">Bathysphyraenops symplex</Emphasis> and the diagnosis of the Howellidae (Perciformes: Percoidei) family

The osteology is described of Bathysphyraenops simplex, and its close relationship is demonstrated with genera Howella and Pseudohowella. These three genera should be classified into separate family Howellidae characterized by the specific structure of the bones of the infraorbital series, the absence of the hyomandibular process of metapterygoideum, and the reduction of the anterior plate of hyomandibulare, the absence of contact of pterygiophores of the 1st and 2nd dorsal fins, presence in front of the second dorsal fin of a free pterygiophore having no distal element, 16 caudal vertebrae, the characteristic structure of scales, and some other characters. The osteological distinctions of Bathysphyraemops simplex from Howella sherborni found for the first time are small and the author believes that some of them may make a case of interspecies variation within these genera. The revised diagnosis of the family Howellidae is presented. The status of the fossil genera Synagropoides and Cottopsis is discussed. They may become representatives of this family.     

Ontogeny of the Early Carboniferous acanthodian <Emphasis Type="Italic">Acanthodes lopatini</Emphasis> Rohon

The sequence of ossification of skeletal elements in the growth series of the acanthodian Acanthodes lopatini Rohon from the Lower Tournaisian of the Minusa Trough (Siberia) is described. Four formal ontogenetic stages are recognized. It is shown that even 20?30-mm-long juveniles have well-developed fin spines, scapulocoracoids, mandibular bones, branchiostegal rays, and incipient gill rakers. At this stage, scales cover the posterior part of the body and the orbits are marked by dark “eye stains” of uncertain nature. Further ontogenetic changes are connected with the development of sclerotic ring elements, sensory line system, squamation of the head region and fin webs, perichondral ossifications of the Meckel’s, quadrate, and palatine cartilages, and, finally, mineralization of the hyoid and gill arches. Ontogenetic features of A. lopatini are compared with those in other members of the genus and other acanthodiforms. Some developmental features shared by A. lopatini and Lodeacanthus gaujicus Upeniece suggest that acanthodids could have evolved from mesacanthids.     

Developmental dynamics of myogenesis in the shipworm <Emphasis Type="Italic">Lyrodus pedicellatus</Emphasis> (Mollusca: Bivalvia)

Background

The shipworm Lyrodus pedicellatus is a wood-boring bivalve with an unusual vermiform body. Although its larvae are brooded, they retain the general appearance of a typical bivalve veliger-type larva. Here, we describe myogenesis of L. pedicellatus revealed by filamentous actin labelling and discuss the data in a comparative framework in order to test for homologous structures that might be part of the bivalve (larval) muscular ground pattern.

Results

Five major muscle systems were identified: a velum retractor, foot retractor, larval retractor, a distinct mantle musculature and an adductor system. For a short period of larval life, an additional ventral larval retractor is present. Early in development, a velum muscle ring and an oral velum musculature emerge. In late stages the lateral and dorsal mantle musculature, paired finger-shaped muscles, an accessory adductor and a pedal plexus are formed. Similar to other bivalve larvae, L. pedicellatus exhibits three velum retractor muscles, but in contrast to other species, one of them disappears in early stages of L. pedicellatus. The remaining two velum retractors are considerably remodelled during late larval development and are most likely incorporated into the elaborate mantle musculature of the adult.

Conclusions

To our knowledge, this is the first account of any larval retractor system that might contribute to the adult bodyplan of a (conchiferan) mollusk. A comparative analysis shows that a pedal plexus, adductors, a larval velum ring, velum retractors and a ventral larval retractor are commonly found among bivalve larvae, and thus most likely belong to the ground pattern of the bivalve larval musculature.

     

Redescription of <Emphasis Type="Italic">Lagocephalus cheesemanii</Emphasis> (Clarke 1897), a senior synonym of <Emphasis Type="Italic">Lagocephalus gloveri</Emphasis> Abe and Tabeta 1983, based on morphological and genetic comparisons (Actinopterygii: Tetraodontiformes: Tetraodontidae)

Lagocephalus gloveri Abe and Tabeta 1983 is shown to be a junior synonym of Tetrodon cheesemanii Clarke 1897 based on examination of morphological characters and DNA analysis of specimens collected from the western North Pacific, Australia and New Zealand. Lagocephalus cheesemanii is distinguished from other species of Lagocephalus by the following combination of characters: spinules on the back in a rhomboidal patch extending from the region between the nasal organ to the posterior part of the pectoral fin; caudal fin double emarginate with middle rays posteriorly produced; dorsal-fin rays 11–15; anal-fin rays 11–14; pectoral-fin rays 15–18; vertebrae 8+11=19; dorsal half of the body dark brown to brownish black; caudal fin dark brown to black with dorsal and ventral white tips. A neotype of L. cheesemanii is designated.     

A new species of labrid fish <Emphasis Type="Italic">Oxycheilinus samurai</Emphasis> from the western Pacific Ocean

A new species of labrid fish Oxycheilinus samurai sp. nov. is described on the basis of five specimens from the Ryukyu Islands, Japan, and Panay Island, the Philippines. The new species is most similar to the Indo-West Pacific species Oxycheilinus orientalis in having a slender compressed body, 12 pectoral-fin rays, a blackish blotch around the anterior portion of the lateral-line anterior series, and a dark blotch basally on the membrane between the first and second dorsal-fin spines. However, O. samurai can be distinguished from O. orientalis by the following combination of characters: gill rakers 4 + 7–8; snout rounded with maximum circumference 49.8–63.5 % of standard length (SL); interorbital width 7.7–9.2 % of SL; caudal-peduncle depth 13.8–15.3 % of SL; posterior margin of caudal fin white; black or dark red area just before white posterior margin of caudal fin; poorly defined blackish blotches on inner surface of opercle in preserved specimens.     

Two new species of deepwater flathead <Emphasis Type="Italic">Bembras</Emphasis> Cuvier, 1829 from the Andaman Sea,eastern Indian Ocean

Two new species of Bembras Cuvier 1829, Bembras leslieknappi sp. nov. and Bembras andamanensis sp. nov., are described from single specimens collected from the Andaman Sea off Myanmar, eastern Indian Ocean, in 2015. The two new species are distinguished from each other and five known congeners by the numbers of anal-fin rays and pectoral-fin rays (15 and 20 in B. leslieknappi vs. 14 and 20–21 in B. andamanensis), forward-slanting body scale rows above the lateral line (80 vs. 74) and upper limb gill rakers (3 vs. 4), as well as by head (41.5 vs. 42.1% SL), snout (14.3 vs. 13.8% SL) and orbit (10.4 vs. 10.9% SL) proportions, and color of the second dorsal (dusky, with blackish spots only on first spine and bases of many soft rays vs. pale, with many scattered blackish spots), pectoral (with a blotch vs. without it) and caudal (both with a broad band) fins.     

<Emphasis Type="Italic">Ostichthys spiniger,</Emphasis> a new species of soldierfish from New Ireland,Papua New Guinea,western Pacific Ocean (Teleostei: Holocentridae)

A new species of soldierfish, Ostichthys spiniger, from off northern New Ireland, Papua New Guinea, is described on the basis of a single specimen collected with a trawl at 180-181 m depth near Kavieng. The new species is characterised by the following characters: scales above lateral line to mid-base of spinous portion of dorsal fin 3¹/₂; no half-scale present anterior to first lateral-line scale; dorsal profile of head nearly uniformly convex; anterior end of each nasal bone with a sharp, forwardly directed spine; a strong spine at the corner of preopercle, which is significantly larger than other serrations; pectoral-fin rays 17; lateral-line scales 29; gill rakers 8 + 13; last dorsal-fin spine shorter than penultimate spine; body depth 2.2 in SL; HL 2.4 in SL; snout very short, 6.6 in HL; least depth of caudal peduncle 4.9 in HL. The new species is compared with other species in the genus. A revised key to the species of Ostichthys is presented. The new species is most similar to O. acanthorhinus.     

A new gonad-infecting species of <Emphasis Type="Italic">Philometra</Emphasis> Costa, 1845 (Nematoda: Philometridae) from the marine fish <Emphasis Type="Italic">Terapon jarbua</Emphasis> (Forsskål) (Terapontidae) off the eastern coast of India

A new nematode species, Philometra terapontis n. sp. (Philometridae), is described from male and female specimens found in the ovary of the jarbua terapon Terapon jarbua (Forsskål) (Terapontidae, Perciformes) from the Bay of Bengal off the eastern coast of India. Based on light and scanning electron microscopical examination, the new species differs from most other gonad-infecting Philometra spp. in the length of the spicules (105–114 μm), a gubernaculum with dorsal, lamella-like structures and a distinct protuberance on its distal end, and a U-shaped, dorsally uninterrupted caudal mound in the male. From a few congeneric, gonad-infecting species with unknown males, it can be distinguished by morphological and biometrical features found in gravid females (i.e. length of body, length of first-stage larvae or oesophagus, and caudal structure), by the host type (fish family) and by the geographical distribution. Philometra terapontis is the first philometrid species reported from a fish belonging to the family Terapontidae. Philometra sawara Quiazon, Yoshinaga &; Ogawa, 2008 is considered a junior synonym of P. scomberomori (Yamaguti, 1935). A key to gonad-infecting species of Philometra parasitising marine and brackish-water fishes is provided.     

A New Species of <Emphasis Type="Italic">Prolibytherium</Emphasis> (Ruminantia,Mammalia) from Pakistan,and the Functional Implications of an Atypical Atlanto-Occipital Morphology

We describe a new species of Prolibytherium, P. fusus, sp. nov., from the lower Miocene of Pakistan, thus extending the genus to Asia. Prolibytherium is otherwise known only from Libya. This species differs from Prolibytherium magnieri in several basioccipital and atlanto-occipital morphologies. Namely, the posterior basioccipital tuberosities are continuous at the midline and lack the elevated transverse ridge seen in P. magnieri, and the notch formed between the lateral occipital condyles and paraoccipital process is lower. Both species of Prolibytherium have a characteristic ventrally fused occipital condyle at the midline, with a notably fuller circumferential articular surface. Prolibytherium magnieri also has thickened dorsal and ventral arches of the atlas. These specimens also possess a longitudinal groove for the Eustachian tube extending from the alisphenoid canal to the bullae, and a second deep grove isolating the basisphenoid bone from the temporal bone. These, plus several other atlanto-occipital morphologies strengthen the cervical support of the head. This is especially important for Prolibytherium, as the taxon possesses massive aliform cranial appendages. We relate the approximation of the occipital condyles to a convergent state in two giraffids (Giraffokeryx punjabiensis and Schansitherium tafeli), each of which possesses multiple pairs of ossicones, presumably necessitating a strengthened atlanto-occipital joint.     

First report of <Emphasis Type="Italic">Ichthyophonus hoferi</Emphasis> infection in young coho salmon <Emphasis Type="Italic">Oncorhynchus kisutch</Emphasis> (Walbaum) at a fish hatchery in Kamchatka

Resting spores of Ichthyophonus hoferi (50–230 μm in diameter) were found in the kidney, heart, liver, skeletalal muscles, exocrine pancreas, and connective and fatty tissues of young coho salmon Oncorhynchus kisutch from the Vilyuisky fish hatchery. In 10% of the fish, there were granulomas and giant cells in these organs. This is the first report of Ichthyophonus infection in Kamchatka.     

Osteology of <Emphasis Type="Italic">Florenciella lugubris</Emphasis> (Percoidei: Epigonidae)

The osteology of Florenciella lugubris is described. F. lugubris is attributed to the family Epigonidae on the basis of specific characters of structure of orbital bones, skull, jaws and hyoid, presence of three principal spines on operculum, contact of pterygiophores of dorsal fins, 10 + 15 vertebrae, extension of the lateral line onto the caudal fin, structure of the first hemapophysis and interhaemale, caudal skeleton, etc. At the same time, Florenciella is more advanced in comparison with Epigonus having such characters as presence of enlarged, directed to sides and/or forward symphyseal teeth in jaws, of finely and densely denticulatd edges of infraorbitalia 2–8 and of the orbiral edge of frontale, and fontanelle in bulla otica and having specific traits of denticulation of opercular bones, having no separated distal element in the free pterygiophore between the first and second dorsal fins, having modified scales, etc. The related genera Florenciella and Rosenblattia may be synonyms.     

Muscles of the genital appendages of Megalopygidae (Lepidoptera) and their significance for the family systematics

Nine muscles were found in the genital complex of Megalopygidae: the paired m1, m2(10), m4, m5(7), m6(5), m7(6), the unpaired m20, m21, and the phallobase muscles. This arrangement corresponds to the ground plan of Zygaenoidea with some reductions. The archaic muscles of the “musculi phallici internus” system, located inside the phallotheca and aedeagus, were revealed for the first time in representatives of the entire superfamily Zygaenoidea. We suggest that the traditional interpretation of m21 as the inner longitudinal muscle of the aedeagus should be preserved, while the inner muscles of the phallotheca should be designated as musculi phallobasi interni m36. Division of the family into two subfamilies, Megalopyginae and the more archaic Trosiinae, is supported by our results, and the homology of the modified appendages of the tergal complex and vinculum is refined. A list of autapomorphies of the family is given.