Morphological description of Cyrtopleura costata (Bivalvia: Pholadidae) from southern Brazil

The aim of the study is to describe in detail, for the first time, the internal and external anatomy of Cyrtopleura costata, which displays ellipsoid and elongated valves with beige periostracum, the anterior adductor muscle unites the valves in the pre-umbonal region, with abduction capacity in its dorsal half, sparing the ligament. Two accessory valves are identified: the mesoplax (calcified) located in the umbonal region; and the protoplax (corneus) above the anterior adductor muscle. Internally there is a pair of well-developed apophysis that supports the labial palps and the pedal muscles, and support part of the gills. The posterior half of mantle ventral edge is fused and richly muscular, working as auxiliary adductor muscle. The siphons are completely united with each other, the incurrent being larger than the excurrent. The foot is small (about ⅛ the size of the animal). The kidneys extend laterally on the dorsal surface, solid, presenting a brown/reddish color. The style sac is well developed and entirely detached from the adjacent intestine. The intestine has numerous loops and curves within the visceral mass. The fecal pellets are coin-shaped. The present study certainly may be used as comparative scenario for specimens from other regions of the species range.

A new species of the Stenopodidean shrimp Genus Spongicola (Crustacea: Decapoda: Spongicolidae) representing the first record of the genus from the Atlantic Ocean

A new species of the spongicolid genus Spongicola, S. liosomatus sp. nov. is described and illustrated based on three male specimens and one female specimen collected from off northern Blanquilla Island, Venezuela, Caribbean Sea at a depth of 135–160 m, representing the first species of the genus found in the Atlantic Ocean. It appears closest to S. levigatus Hayashi & Ogawa, 1987, S. teres Komai, 2015 and S. inflatus de Saint-Laurent & Cleva, 1981 in having reduced armature on the body and appendages. However, the unserrated ventral edge of the third pereiopods and the membranous ridges of the first and second pereiopod cutting edges, distinguish the new species from these three species as well as all other members of the genus.

The larvae of Limnephilus minos Malicky 1970 and Mesophylax impunctatus aduncus (Navás 1923) (Trichoptera: Limnephilidae), including a discriminatory matrix for the Greek limnephilid larvae with multifilament gills

Limnephilus minos Malicky 1970 is a micro-endemic caddisfly restricted to the Greek island of Crete. Mesophylax impunctatus aduncus (Navás 1923) is known from Turkey and the southern Balkan peninsula; Greek records range from islands close to the mainland and Skiros to the northern mainland, and Attica. This paper describes the previously unknown larvae of both taxa. Information on the morphology of the 5th larval instar of each taxon is given, and the most important diagnostic characters are illustrated. A discriminatory matrix for the Greek limnephilid larvae with multifilament gills is also provided. In the context of existing identification keys, the larva of L. minos belongs to the group of Limnephilini larvae where face setae are lacking on the mid- and/or hind femora; the species keys together with L. auricula Curtis 1834 and can be separated from the latter species by setae present between the primary setae on the distal section of mid- and hind trochanters. In contrast, face setae are present on the mid- and/or hind femora in M. impunctatus aduncus. Its larva can be easily identified by the fact that 3 or more ventral-edge setae are present on the midfemur, by setae present on both sides of the anal slit, and by its grazer-type mandible lacking terminal teeth.

An improved extraction method reveals varied DNA content in different parts of the shells of Pacific oysters

The DNA in the shell of Crassostrea gigas could have important roles in the shell biomineralization. However, limited by the low efficiency of existing extraction methods, studies investigating the DNA in shells are lacking. In this study, the shell DNA of C. gigas was extracted using the organic solvent extraction (OSE) and guanidine lysis buffer (GLB) methods; the efficiency and quality of these two methods were compared. The sequences of a mitochondrial gene (cytochrome c oxidase subunit I, COI) and a nuclear gene (28S rRNA) of C. gigas were analyzed to verify the origin of the extracted shell DNA. Finally, the DNA contents of the ventral edge, middle part, and dorsal edge of C. gigas shells were compared. The results showed that OSE had a higher DNA extraction efficiency than GLB; the oyster shell DNA was homologous to the oyster genome; the DNA content was higher in the ventral edge than in the middle part or in the dorsal edge of the C. gigas shell. This study not only reports an improved extraction method for the mollusk shell DNA, but also revealed that the DNA in the oyster shell originates from the oyster body and that the DNA content in different parts of the C. gigas shell showed obvious variance. These results provide supporting evidence for the hypothesis that oyster cells participate in shell formation, and also afford a nondestructive method for oyster genetic identification, which can promote the application of molecular biology technology in oyster breeding. In addition, a shell growth pattern of ‘Under Old & Exceeding Old’ was also proposed.

Successful resection of pancreatic head cancer in a patient with circumportal pancreas: a case report with technical consideration

We report a case of pancreaticoduodenectomy for pancreatic head cancer with circumportal pancreas (CP). A 76-year-old woman was referred to our hospital with complaint of generalized pruritus. Dynamic computed tomography (CT) revealed an unenhanced mass at the head of the pancreas and a dilated main pancreatic duct (MPD) behind the superior mesenteric vein (SMV). She was diagnosed with pancreatic head cancer with CP and underwent subtotal stomach-preserving pancreaticoduodenectomy (SSpPD). The pancreas was transected both beneath and above the SMV, and the dominant dorsal edge of the pancreas was mobilized and anastomosed with the gut, whereas the ventral edge was closed by suture and attached to the gut. The postoperative course was uneventful without the occurrence of pancreatic fistula or bleeding. CP is a rare anomaly in which a portal vein (PV) is encircled by the annular pancreatic parenchyma. CP is usually asymptomatic without any significant comorbidity but may become a surgical hazard when pancreaticoduodenectomy is performed. We report our successfully treated case, with special references to the technical approach for pancreatic anastomosis.

Development of the larval and juvenile shell of boring bivalve Zirfaea crispata (Bivalva, Pholadidae) in the White Sea

Development of the larval and juvenile shells of the White Sea bivalve Zirfaea crispata has been studied. The main stages of shell development from D-stage to early juveniles were described. The formation of larval hinge, consisting of two small teeth on the left valve and two teeth of different size on the right valve was observed. The complex shape of the large tooth on the right valve was noted at the premetamorphosis stages. Development of a structure, typical for certain Pholadidae - an articular connection on the ventral edge of the shell was recorded. This connection consists of a rectangular tooth on the right valve and a depression, flanked by small projections, on the left valve. The ventral connection starts to form at the larval size of 300 µm and becomes fully formed prior to metamorphosis. After metamorphosis the ventral connection does not disappear, but continues to grow with the growing edge of dissoconch. The role and functional importance of this structure in Zirfaea is discussed.

A new species of leaffish Polycentrus Müller & Troschel, 1849 (Percomorpha: Polycentridae) from the rio Negro, Brazil

A new species of Polycentrusis described from the rio Negro, in Brazil. It is distinguished from P. schomburgkii by the presence of two dark postocular and one subocular band, all smaller than orbital diameter, blunt snout, isognathous mouth, reduction of the serrations on the lower edge of the lacrimal-spines ranging from zero to two tiny spines at the posterior end, intensely serrated edge of the interopercle, fully serrated posterior edge of the vertical arm of the preopercle, presence of five pungent opercular spines, subopercle broadly serrated along most of its posterior ventral edge, presence of serrations dorsally on the posterior margin of the cleithrum, fourth ray of pectoral fin reaching the vertical through the anal-fin origin, 19-21 predorsal scales, 19-20 scales on dorsal-fin base, 12-14 scales on anal-fin base, and absence of a median opercular blotch.

Swedish Plectida (Nematoda). Part 3. The genus Loveninema gen. n.

A new genus Loveninema gen. n., with two new species L. tubulosa gen. n., sp. n. and L. unicornis gen. n., sp. n. is de-scribed from bottom sediments collected in Skagerrak off the west coast of Sweden. Loveninema gen. n. is unique amongother genera of Plectida by possessing a midventral labial projection located on the ventral edge of the oral opening andprotruding anteriorly. Other diagnostic characters include: sclerotised labial framework in the shape of a conoid ring withthree projections extending posteriorly: one mid-dorsal, one left-subventral and one right-subventral; papilliform outer la-bial and cephalic sensilla; amphidial fovea a transverse slit located anterior to cephalic sensilla bases; excretory pore open-ing on the ventral side of the labial region; pharynx uniformly muscular, cylindrical; female reproductive systemdidelphic, amphidelphic; male reproductive system monorchic, with reflexed testis; spicules present; gubernaculum pres-ent or absent; either alveolar or tubular supplements present in males, absent in females; caudal glands and spinneret pres-ent. L. tubulosa gen. n., sp. n. is particularly characterised by the 0.66–1.12 mm long body; short midventral labialprojection; straight vagina without sclerotisations; male without alveolar and with 12–15 tubular supplements, 15.0–21.5µm long spicules, and with gubernaculum. L. unicornis gen. n., sp. n. is particularly characterised by the 0.65–0.98 mmlong body; long midventral labial projection; straight vagina without sclerotisations; male with up to 20 alveolar and without tubular supplements, 11.5–14.0 µm long spicules, and without gubernaculum.

A new species and a new genus of Parabathynellidae (Crustacea, Syncarida) from South Korea

Arisubathynella gen. nov. is established for a new species, A. cheongmiensis sp. nov. from South Korea. An illustrated description is given. The new genus stands out in the family Parabathynellidae by six-segmented antennules, three-segmented antenna without medial seta on inner margin of third segment, absence of mandibulartooth of the ventral edge, bare proximal segment of maxilla, two-segmented exopods of thoracopods II-VII, and male thoracopod VIII with elongated external lobe. Arisubathynella gen. nov. is the fourth genus known from South Korea and foreshadows the great diversity of bathynellaceans in the Far East.

Morphological studies on lyssa in cats and dogs

The aim of this study is to reveal the morphology of the lyssa in the cat and dog. Eight heads of adult healthy cats and eight heads of dogs of both sexes were used as materials. In the cat the lyssa, yellow coloured, had a helical appearance and its edge facing the oral cavity became sharp; in the dog the lyssa, pinkish white coloured, was more or less J-shaped. The whole body of the cat’s lyssa was buried among the intrinsic lingual muscles. In the dog, although aboral, two thirds of the lyssa were squeezed among the intrinsic lingual muscles, its cranial third was placed just under the mucosa to protrude slightly into the oral cavity. In both species, the whole body of the lyssa was determined to have been formed by the nearly adipose tissue in which occasional striated muscles existed. Moreover, in the middle third of the dog’s lyssa, dense striated muscle fibres were seen dorsally to the adipose tissue, and we also noticed with interest that the lyssa sheath embracing this part contained few muscle spindle-like structures. It was of interest that in the cat a pyramidal rod encircled by a fine capsule of connective tissue was attached to the ventral edge of the cranial third of the lyssa.