A new sisorid catfish of the genus Pseudolaguvia (Teleostei: Sisoridae) from Nagaland, north-eastern India

Pseudolaguvia vespa, new species, is described from the Tsücha River, Mokokchung district, Nagaland, India. The new species can be distinguished from congeners in having the following combination of characters: length of dorsal-fin spine 12.3–16.8% SL, a smooth anterior edge of the dorsal-fin spine, caudal peduncle depth 9.0–10.5% SL, body depth at anus 15.6–17.7% SL, caudal fin length 20.7–24.5% SL, pectoral fin length 20.1–24.1% SL, interorbital distance 22.7–28.1% SL, thoracic adhesive apparatus extending to midway between base of last pectoral-fin ray and pelvic-fin origin, and live specimens with two irregular, chrome-yellow bands on the body.

Assessing the migratory histories, trophic positions, and conditions of lake sturgeon in the St. Croix and Mississippi Rivers using fin ray microchemistry, stable isotopes, and fatty acid profiles

Background Reproducing populations of invasive carps (Hypophthalmichthys spp.) could alter aquatic food webs and negatively affect native fishes in the Mississippi National River and Recreation Area (MISS) and the St. Croix National Scenic Riverway (SACN). However, proposed invasive carp barriers may also threaten populations of native migratory fishes by preventing movements of fish between rivers that are necessary for life history requirements. In this study, nonlethal chemical techniques were used to provide baseline data related to the condition, trophic position, and migratory histories of lake sturgeon (Acipenser fulvescens) captured in the Mississippi and St. Croix Rivers. Results Fish length and weight measurements and age estimates determined from pectoral fin rays demonstrated that lake sturgeon from the Mississippi River had greater lengths-at-age compared to sturgeon from the St. Croix River. However, length–weight relations were similar for sturgeon from the Mississippi and St. Croix Rivers. Lake sturgeon captured from different locations had distinguishable fatty acid signatures, and stable isotope analyses demonstrated that lake sturgeon from the Mississippi River generally feed at a higher trophic level than those in the St. Croix River. Strontium-to-calcium ratios (Sr:Ca) from fin ray cross sections indicated that sturgeon captured from the Mississippi River had higher Sr:Ca values than sturgeon captured from the St. Croix River, and natal origins and capture locations were not significantly different among sturgeon captured within individual rivers. Most sturgeon were captured in water with a similar Sr:Ca signature as their natal waters, indicating that there is some separation between populations of lake sturgeon in the St. Croix and Mississippi Rivers. However, Sr:Ca data indicated substantial variation in movement patterns among individual lake sturgeon, indicating that populations interact through migrations of individual fish between rivers. Conclusions Study results provide baseline condition and food web structure index data for assessing changes in lake sturgeon populations should invasive carps become established in these areas of the Mississippi and St. Croix Rivers. Controlled-exposure and telemetry studies would help verify and enhance the relations between Sr:Ca signatures in water and lake sturgeon pectoral fin rays to further assess mixing of sturgeons between rivers.

Morphology characteristics and length weight relationship of sucker barb fish (Barbichtyhys laevis Valenciennes 1842)

Sucker barb fish is one of the potential of fish resources in Tasik river. This study aimed to determine the morphometric and meristic characteristics of the growth of sucker barb fish in the Tasik River. The method used in this study is a survey method using the fishing net and gillnet with mesh size 1,5 inches. The nets are placed in the afternoon, then lifted in the morning. This is done 3 times with a span of 2 weeks in the three research stations. The number of samples collected were 135 fish. The morphometric characteristics of sucker barb fish are bodyweight (BT) ranging from 9-85 g, total length (PT) ranging from 100-230 mm, standard length (PS) ranging from 75-176 mm, head length (PK) of 20-42 mm, snout length (PM) of 30 mm, the height of dorsal fin (TSP) of 40 mm, length of the base of dorsal fin (PPSP) of 15-30 mm, eye diameter (DM) of 10 mm, caudal peduncle (TBE) of 8-22 mm, body height (TB) of 17-40 mm, pectoral fin length (PSD) of 30 mm and pelvic fin length (PSP) of 25 mm. Meristic characteristics are the characteristics of counting the scales and fins of sucker barb fish. The number of scales in the lateral lines (LL) is 35-38, the body coiled scales (SMB) are 6, the scales around the pectoral fin (PF) P 10-14, anal fin (AF) A 8 and caudal fin (CF) C 18. The growth pattern of sucker barb fish in the Tasik River is allometric negative

Morphological description of deepwater skate Bathyraja trachura from the North-West Pacific

Morphological description is given for deepwater skates Bathyraja trachura caught in the North-West Pacific in 1980–1989, both juveniles and adults. Counts for vertebras, pectoral fin, teeth rows, and intestinal valves are presented.

Callogobius falx, a new species of goby from southern Japan

Callogobius falx n. sp. (Gobiidae) is described on the basis of two specimens (14.4 and 23.1 mm in standard length: SL) from the Ryukyu Islands, southern Japan. The new species is characterized by the following combination of characters: dorsal-fin rays VI-I, 8 or 9; anal-fin rays I, 7; pectoral-fin rays 18 or 19; lateral scale rows 20–22; body depth moderate, neither particularly slender nor deep (depth at pelvic-fin origin 18.3–20.0% of SL); pelvic-fin base with frenum; caudal-fin length moderate, margin rounded; cephalic sensory-canal pores absent; interorbital papillae row separated, forming two rows (one row in 14.4 mm paratype); postorbital papillae row not continuous with upper cranial papillae row; preopercular and transverse opercular papillae rows connected, forming single transverse row; body with three oblique black bars, angled upwards anteriorly and continuous with black bars on dorsal fins, anteriormost bar extending from 1st dorsal fin to midline of body, posterior two bars extending from second dorsal fin to dorsal surface of body and caudal peduncle, respectively; pectoral fin white, upper half widely (ca. 1/2 length of rays) margined with black; caudal-fin base with narrow sickle-like bar.

Osteodiscus abyssicola, a new snailfish (Cottoidei: Liparidae) collected off the Pacific coast of northern Japan

The snailfish Osteodiscus abyssicola sp. nov. is described from a single specimen collected off the Pacific coast of Hokkaido, northern Japan, at a depth of 4,671–4,744 m. It is distinguished from all currently recognized congeners by the following combination of characters: vertebrae 49; dorsal-fin rays 44; anal-fin rays 39; principal caudal-fin rays 8; pyloric caeca 5; mouth horizontal; teeth on both jaws simple and sharp, without cusps; upper and lower jaw symphyses without diastema; cephalic pore sizes moderate, similar to or slightly larger than nostril; gill slit extending ventrally to 2nd pectoral-fin ray base; pectoral fin notched; mandibular symphysis to center of anus 101.6% head length (HL); posterior edge of pelvic disk to center of anus 15.5% HL; epural 1, reduced; epipleural ribs absent. An emended diagnosis and key to the species of Osteodiscus are provided.

Pectoral-fin glands and delivery apparatus in the catfish genus Brachyrhamdia Myers, 1927 (Siluriformes: Heptapteridae)

The Siluriformes, popularly known as catfishes, are probably the vertebrate group with the highest diversity of venomous animals, even though only approximately a hundred venomous catfishes are reported to date. Venomous catfishes might present a delivery system apparatus, formed by an unbranched ray at the leading edge of pectoral and dorsal fins (spine), which can be stiffened and pungent, while venom glands can be present at the surface of such spines and/or the axillary region. This work investigated the presence, morphology and distribution of glands and pectoral-fin delivery apparatus in the heptapterid Brachyrhamdia genus. Pectoral-fin spine external morphology was compared across all valid species in the genus, histological sections of the pectoral-fin spine and axillary regions of B. heteropleura and B. marthae were produced, and dissections of the pectoral girdle region of the mentioned species were analyzed. The histological sections confirmed the presence of pectoral-fin glands at the surface of the pectoral-fin spine of Brachyrhamdia species, and cellular morphology indicates these glands are probably venomous. Also, we found a piriform gland at the axillary region, whose cell morphology is like the reported for other catfishes. However, we cannot currently confirm or deny axillary gland participation in the venom delivery apparatus. This work constitutes the first report of venom glands in Brachyrhamdia, and the first description of Heptapteridae axillary glands.