Daphnia (Ctenodaphnia) Mediterranea: A new species of hyperhaline waters,long confused with D. (C.) Dolichocephala Sars, 1895.

A very particular form of Daphnia (Ctenodaphnia), adapted to life in epicontinental hyperhaline waters of Mediterranean arid regions had long been confused with Daphnia (Ctenodaphnia) dolichocephala Sars, 1895. In this paper the morphological and ecological differences between the two taxa are pointed out and comparison is made with another closely related Rumanian form (Daphnia cf. mediterranea) and with the related Spanish species (D. atkinsoni and D. chevreuxi). The Daphnia of saline environments is described here as Daphnia (Ctenodaphnia) mediterranea. The most important differential characters of this new species are: 1) the short and widely rounded rostrum; 2) dorsal ridge of the female extends to the anteriormost part of the head; 3) elliptical ephippium with a ride anterior margin; convex shape and separate from the dorsal ridge; 4) males possessing a very long antennule base that reaches the distal limit of the head.     

Formation of the insect head involves lateral contribution of the intercalary segment, which depends on Tc-labial function

The insect head is composed of several segments. During embryonic development, the segments fuse to form a rigid head capsule where obvious segmental boundaries are lacking. Hence, the assignment of regions of the insect head to specific segments is hampered, especially with respect to dorsal (vertex) and lateral (gena) parts. We show that upon Tribolium labial (Tc-lab) knock down, the intercalary segment is deleted but not transformed. Furthermore, we find that the intercalary segment contributes to lateral parts of the head cuticle in Tribolium. Based on several additional mutant and RNAi phenotypes that interfere with gnathal segment development, we show that these segments do not contribute to the dorsal head capsule apart from the dorsal ridge. Opposing the classical view but in line with findings in the vinegar fly Drosophila melanogaster and the milkweed bug Oncopeltus fasciatus, we propose a “bend and zipper” model for insect head capsule formation.     

<Emphasis Type="Italic">Paraliparis adustus</Emphasis> and <Emphasis Type="Italic">Paraliparis bullacephalus</Emphasis>: two new snailfish species (Teleostei: Liparidae) from Alaska

Paraliparis adustus sp. nov., a snailfish species from the Bering Sea near the Aleutian Island Archipelago, Alaska, is described based on a single mesopelagic specimen. This new species is clearly distinguished by a combination of several morphological features and meristic counts, including long pointed gill rakers with 0–3 spinules at or near the tip, anus positioned forward near the pectoral symphysis, and color uniform brown. Paraliparis bullacephalus sp. nov. from Shelikof Strait, Gulf of Alaska, is also described. This new species is very similar in meristic characters and general body shape and size to P. holomelas Gilbert, but differs primarily in morphological features of the head, particularly in the shape of the dorsal contour of the head, snout, and opercular flap, mouth size, and eye position.     

The evolution of "deformed" brains in ant-like stone beetles (Scydmaeninae, Staphylinidae)

We present the first study of the central nervous system of adult representatives of Scydmaeninae. Histological staining, scanning electron microscopy and computer-based 3D reconstruction techniques were used to document the shape and configuration of the major cephalic elements of the central nervous system and to explain its anomalies compared to other Coleoptera. For the first time we report the presence of cephalic glands in ant-like stone beetles: in Scydmaenus (Cholerus) hellwigii openings of voluminous glands are located near the occipital constriction and their secretion accumulates in a large cavity of the dorsal head region. In Scydmaenus (Cholerus) perrisi the proto-, deuto-, tritocerebrum and the suboesophageal ganglion together form a large and compact ganglionic mass around the anterior foregut in the retracted neck region of the head. We exclude miniaturization as the driving force of the observed modifications. Comparative study of the head anatomy of S. perrisi, S. hellwigii, Scydmaenus (s. str.) tarsatus, Scydmaenus (Parallomicrus) rufus and Neuraphes elongatulus suggests a possible evolutionary scenario. We propose an evolutionary reversal hypothesis, involving a) the displacement and concentration of the cephalic central nervous system induced by the development of glandular cavities of the head, followed by b) a reduction of the glandular structures, without a secondary relocation of the cephalic CNS. The interpretation of head modifications in Scydmaeninae in the light of such a scenario may turn out as important for the reconstruction of the phylogeny and evolution of this highly successful group of beetles.     

Early life history stages of peacock flounder Bothus lunatus (Bothidae) from the western and central tropical Atlantic

Previously unknown larvae and poorly studied metamorphic and postmetamorphic stages of development of peacock flounder Bothus lunatus (Bothidae) with a length of 5.4 to 39.5 mm from the western and central tropical waters of the Atlantic Ocean are described, and their identification is substantiated. Small-and medium-sized larvae of this species (with a length of nearly 10 mm) at stages of pre-and postflexion, like all larvae of the genus Bothus at the corresponding stages of development, have a strongly flattened from the sides, moderately deep, and almost pigment-free transparent body; bear a long anterior ray in the dorsal fin; and have single melanophores in the end part of the body. They differ from larvae of other Atlantic species of the genus known at early stages of development in the shape of the anterior head profile, namely in the presence of a deep notch in front of the eyes. With growth, their body assumes a rounded shape. During metamorphosis of larval B. lunatus, the right eye shifts to the left side of the head through a slit formed during the separation of the origin of dorsal fin base from the cranium. This specific feature distinguishes them from larvae of the remaining species of the genus in which, during metamorphosis, the right eye passes to the left side through the hole in the head.     

Halichoeres bleekeri (steindachner & döderlein), a valid japanese species of labrid fish, distinct fromH. tenuispinis (günther) from china

Halichoeres bleekeri (Steindachner &; Döderlein, 1887), previously regarded as a junior synonym ofH. tenuispinis (Günther), is a valid species. It is distinct fromH. tenuispinis in nearly always having 13 instead of 14 pectoral rays. 11–15 instead of 7–11 suborbital pores, longer dorsal soft rays (1.95–2.3 in head length vs 2.25–2.4 fortenuispinis). and some features of color such as the absence of a dark spot at the upper base of the caudal fin of the female.H. tremebundus Jordan and Snyder, 1902 is a synonym ofH. bleekeri based on the female form, andArtisia festiva de Beaufort is a synonym ofH. tenuispinis, also described from the female phase,H. bleekeri is known from Korea and in Japan from Tokyo to the Izu Islands.H. tenuispinis is recorded from Hong Kong and Xiamen. China, and Taiwan. Records ofH. tenuispinis from the Philippines by Fowler and Bean (1928) represent misidentifications ofH. papilionaceus (Valenciennes).     

Morphology and ciliary pattern of some rare haptorid ciliates, with a description of the new family Kamburophryidae (Protists, Haptoria)

We investigated three rare haptorid ciliates, viz., Lagynophrya gibba Kahl (1935), Enchelys lajacola nov. spec., and Spathidium implicatum Kahl (1930), using live observation, silver impregnation, morphometry, and scanning electron microscopy. Lagynophrya gibba, which was rediscovered in peatland soil from Iceland, is referred to a new genus, Kamburophrys, and a new family, Kamburophryidae, based on a unique organelle, the brush membranoid. This structure is near the dorsal brush and composed of very narrowly spaced cilia, about 5 μm long. The genus Kamburophrys has a unique combination of features, viz., an oral cone on the oral bulge, an oblique circumoral kinety, and a subapical hump carrying the three-rowed dorsal brush and the brush membranoid. The Kamburophryidae possibly belong to the order Spathidiida. Enchelys lajacola was discovered in mud from granitic rock-pools (Lajas) in Venezuela, South America. The new species is characterized by a bottle-like shape, a macronucleus with the shape of a curved strand, a heterostichad dorsal brush, and rod-shaped toxicysts. Spathidium implicatum, which was rediscovered in an ephemeral meadow puddle near Salzburg city centre, is neotypified and referred to the genus Apertospathula because it has an open circumoral kinety.     

Morphology of Females and Cysts of Globodera tabacum tabacum,G. t. virginiae,and G. t. solanacearum (Nemata: Heteroderinae)

Detailed morphological comparisons with light and scanning electron microscopy were made of white females and cysts of several isolates of Globodera tabacum sspp. tabacum (GTT), virginiae (GTV), and solanacearum (GTS). Observations focused on body shape, anterior region including head shape, lip pattern, stylet morphology, and the terminal area in females; and body shape and terminal area of cysts. The most useful characters to separate the three subspecies were forms of the female body, cyst, stylet knobs, tail region, perineal tubercles, anal-fenestral ridge patterns, and the distinctiveness of the anus. GTT is characterized by having round females and cysts, sharply back sloped stylet knobs, clumped perineal tubercles in the vulval region, tight parallel ridges in the cyst anal-fenestral region, and a uniformly conoid tail region. GTV is characterized by its ovoid to ellipsoid female and cyst shape, the "Dutch shoe" shape of the dorsal stylet knob, the more dispersed perineal tubercles, a maze-like pattern of ridges in the anal-fenestral region, and an indistinct anus. GTS is characterized by its ovoid to ellipsoid female and cyst shape, moderately backward sloped stylet knobs, more widely separated ridges, a distinct anus, and a usually crescent shaped tail region. Much variability in shape and patterns is visible among all the isolates of the different subspecies. Tubercles in the neck, as well as bullae, are reported, and their taxonomic value is discussed.     

Two new species of the tribe Hymenaphorurini Pomorski, 1996 (Collembola: Onychiuridae) from Korea

Two new species, Heteraphorura koreana sp. nov. and Psyllaphorura jirisana sp. nov., of the tribe Hymenaphorurini are described and illustrated based on materials from South Korea. Heteraphorura koreana sp. nov. belongs to the oriental species-group of the genus Heteraphorura, because of compound vesicles in the postantennal organ. This new species shares the same number of PAO with Heteraphorura pseudoseolagensis (Martynova, 1981) from Russia, but differs in pso dorsal formula and lateral teeth of claw. Psyllaphorura jirisana sp. nov. is similar to Psyllaphorura sensillifera.(Martynova, 1981) from the Russian Far East, but can be distinguished by shape of vesicles in PAO, dorsal s-chaetae on head and ratio AS/unguis. www.zoobank.org/urn:lsid:zoobank.org:pub:F854CBFD-06D0-4396-B8D9-62468B427111.     

Morphological responses of a stream fish to water impoundment

Water impoundment imposes fundamental changes on natural landscapes by transforming rivers into reservoirs. The dramatic shift in physical conditions accompanying the loss of flow creates novel ecological and evolutionary challenges for native species. In this study, we compared the body shape of Cyprinella venusta collected from eight pairs of river and reservoir sites across the Mobile River Basin (USA). Geometric morphometric analysis of the body shape showed that river populations differ from reservoir populations. Individuals inhabiting reservoirs are deep-bodied and have a smaller head, a more anterior dorsal fin, a shorter dorsal fin base and a more ventral position of the eye than C. venusta in streams. The direction of shape divergence within reservoir–river pairs was consistent among pairs of sites, and the shape of C. venusta in reservoirs is strongly correlated with reservoir size. These findings show that physical characteristics of reservoirs drive changes in the morphological attributes of native fish populations, indicating that water impoundment may be an important, yet largely unrecognized, evolutionary driver acting on aquatic biodiversity.     

Homatula laxiclathra (Teleostei: Balitoridae), a new species of nemacheiline loach from the Yellow River drainage in Shaanxi Province, northern china

Homatula laxiclathra, new species, is here described from the Wei-He of the Yellow River drainage in Shaanxi Province, northern China. It is similar to H. berezowskii, H. longidorsalis, and H. variegata in the shared possession of a shallower body with a uniform depth, a character distinguishing all of them from all other congeners, but differs from these three species in the width of vertical brown bars on the caudal peduncle. This new species, along with H. berezowskii, differs from H. longidorsalis, and H. variegata in head length, caudal-peduncle depth, length of the dorsal adipose creast of the caudal peduncle, body squamation, and intestinal coiling. Homatula laxiclathra and H. berezowskii are further distinct in the caudal-fin shape and interorbital width.     

Surface specializations of the epithelial cells at the tip of the optic tentacle,dorsal surface of the head and ventral surface of the foot in Helix aspersa

Summary Morphologically the surface specializations of the epithelium covering the dorsal head and ventral foot regions in Helix aspersa consists either of cilia or microvilli respectively. The epithelium at the tip of the optic tentacle is a simple one. Each epithelial cell has a number of cilia-like projections from their free surfaces. These projections usually branch at their tips into two or three slender, microvilli-like structures. From the bases of the cilia-like projections arise numerous, tubular processes which form a thick, spongy layer interspersed between these projections. The microvilli-like structures are immersed in a fine, fibrous mat; unlike the fibrous mats on the dorsal head and ventral foot epithelia this material does not autofluoresce. It is suggested that it arises from the collar cells and not from typical mucocytes. The functional relationship between these surface specializations of the optic tentacle epithelium and the abundance of sensory axons in this region is discussed. These epithelial cell projections on the tentacle probably function not only as a protective covering but also to create a fluid trap for odours in the ambient air. The various contacts between epithelial cells serve to maintain the integrity of the epithelium while allowing for stretching due to protrusion of the tentacle.This work has been supported by the Australian Research Grants Committee.     

Morphological and Molecular Characterization of a New Root-Knot Nematode,Meloidogyne thailandica n. sp. (Nematoda: Meloidogynidae), Parasitizing Ginger (Zingiber sp.)

A root-knot nematode Meloidogyne thailandica n. sp. was discovered on roots of ginger (Zingiber spp.) intercepted from Thailand in October 2002 by the U.S. Department of Agriculture Animal and Plant Health Inspection Service at the port of San Francisco. Comparison by light microscopy (LM) and scanning electron microscopy (SEM) to five other morphologically related species (M. incognita, M. arenaria, M. microcephala, M. megatyla, and M. enterolobii) revealed that the new species differs from these by one or more of the following: body, tail and hyaline tail length, shape of head, tail and tail terminus of second-stage juveniles; stylet length and shape of spicules in males; perineal pattern, stylet length and shape of knobs in females. The distinctive perineal pattern is oval to rectangular, with smooth to moderately wavy and coarse striae, and with characteristic radial structures present underneath the pattern area; the dorsal arch is high, sometimes round to rectangular, and striae in and around the anal area form a thick network-like pattern interrupted by lateral lines and large phasmids. Second-stage juveniles have a long, slender tail and long, gradually tapering hyaline tail region ending in a rounded terminus. Male spicules commonly have an acutely angled shaft with a bidentate terminus. Molecular data from the ribosomal large subunit D3 expansion segment revealed four haplotypes, two of which were unique and distinguish M. thailandica n. sp. from M. arenaria, M. incognita, and M. javanica.     

A new gobiid fish,Fusigobius signipinnis,from the western tropical Pacific

An undescribed goby has been collected from several localities in the western troplcal Pacific, from Japan to Australia. This species is described as a new species,Fusigobius signiplnnis. It differs from other species ofFusigobius in pectoral ray counts, colouration, largely separate pelvic fins, and shape of the first dorsal fin. The species is found in groups on sand, frequently flicking its first dorsal fin. Males are larger than females in mean size. Sex ratios are uneven, and females are twice as numerous as males.     

A new loach, Cobitis shikokuensis (Teleostei: Cobitidae), from Shikoku Island, Japan

A new species of spinous loach, Cobitis shikokuensis, is described based on 297 specimens from Shikoku Island, Japan. The new species was formerly known as the Shikoku group of Cobitis takatsuensis. It can be distinguished from other species of Cobitis and closely related genera by a combination of the following characters: dorsal fin with 6 branched soft rays; anal fin with 5 branched soft rays; one brownish streak across eye from the tip of nose, no streak on cheek; a black spot smaller than eye diameter near the dorsal corner of the caudal fin base; 3–5 small brownish speckles on ventral side of caudal peduncle; high caudal peduncle with well-developed fleshy keels on dorsal and ventral side; a lamina circularis at base of dorsal part of pectoral fin absent; first branched soft ray of pectoral fin broad in males; pectoral soft rays widely branched from the approximate midpoint; last anal fin ray with 2 elements; interorbital width 11.2–17.1% of head length.     

Functional analysis of Scr during embryonic and post-embryonic development in the cockroach, Periplaneta americana

The cockroach, Periplaneta americana represents a basal insect lineage that undergoes the ancestral hemimetabolous mode of development. Here, we examine the embryonic and post-embryonic functions of the hox gene Scr in Periplaneta as a way of better understanding the roles of this gene in the evolution of insect body plans. During embryogenesis, Scr function is strictly limited to the head with no role in the prothorax. This indicates that the ancestral embryonic function of Scr was likely restricted to the head, and that the posterior expansion of expression in the T1 legs may have preceded any apparent gain of function during evolution. In addition, Scr plays a pivotal role in the formation of the dorsal ridge, a structure that separates the head and thorax in all insects. This is evidenced by the presence of a supernumerary segment that occurs between the labial and T1 segments of RNAiScr first nymphs and is attributed to an alteration in engrailed (en) expression. The fact that similar Scr phenotypes are observed in Tribolium but not in Drosophila or Oncopeltus reveals the presence of lineage-specific variation in the genetic architecture that controls the formation of the dorsal ridge. In direct contrast to the embryonic roles, Scr has no function in the head region during post-embryogenesis in Periplaneta, and instead, strictly acts to provide identity to the T1 segment. Furthermore, the strongest Periplaneta RNAiScr phenotypes develop ectopic wing-like tissue that originates from the posterior region of the prothoracic segment. This finding provides a novel insight into the current debate on the morphological origin of insect wings.     

A New Species of Pristionchus (Rhabditida: Diplogastridae) and Its Bacterial Symbiont from Yixing,China

A new nematode species, Pristionchus entomophilus n. sp., was collected during a soil sample survey in Yixing of Jiangsu province, eastern China. P. entomophilus n. sp. is distinguished by its unique characteristics. This new species is mainly hermaphroditic, with males seldom found. The new nematode has a similar body length but has much narrower body width compared with P. pacificus. Its body is covered with longitudinal ridges: 12 ridges on head, 13 or 14 ridges in the middle, 11 and 7 ridges in front and rear of the anus, respectively. The eurystomatous form mouth includes a triangular dorsal tooth, a large claw-like right subventral tooth, and a row of five ventral denticles placed opposite the dorsal tooth. Only eight pairs of genital papillae and a pair of phasmids are present in the tail of the male as the sixth pair of papillae having seemingly been degenerated and lost. Molecular phylogenetic trees based on 18S rDNA confirmed that the new species belongs to the genus Pristionchus and is most closely related to P. pacificus. Moreover, the new species was found to be occasionally associated with the entomopathogenic bacterial strain 09FLYB1 of Serratia nematodophila and be able to stably transfer the bacterial strain for several generations.     

The morphology of the larval stages of three species (Arrenurus mediorotundatus Thor, 1898; Arrenurus conicus Piers 1894; and Arrenurus cylindratus Piers, 1896) of the Megaluracarus subgenus (Acari: Hydrachnidia: Arrenuridae)

The morphology of the larval stages of three species (Arrenurus mediorotundatus, Arrenurus conicus and Arrenurus cylindratus) belonging to the Megaluracarus subgenus is described. Particular attention is paid to the common characters of the three species in which they differ from the other species belonging to the other subgenera. These are: the shape of the excretory pore plate, the shape of the dorsal plate, the length of coxal plate II medial margin and the C1-CpI, C4-CpIII distances. Other characters differ between the three species also. These are: the shape of the dorsal plate, the shape of coxal plate III, the shape of excretory pore plate and the presence or absence of secondary setae of the IFe3 setae.