A new species of the waspfish genus Ocosia (Teleostei: Tetrarogidae) from the Coral Sea, with a key to species in the genus

The new waspfish Ocosia dorsomaculata n. sp. (Tetrarogidae) is described, based on specimens from Australia (5) and New Caledonia (51). Although O. dorsomaculata and Ocosia apia Poss & Eschmeyer 1975 both share modally XVI, 8 dorsal-fin rays with a long second dorsal-fin spine, and presence of supraocular, lateral lacrimal, and suborbital spines, the former has modally 13 pectoral-fin rays (vs. usually 12 in the latter), a lower modal count of total gill rakers (10 vs. 16–18), greater upper-jaw length, greater third to sixth dorsal-fin spine lengths, the third dorsal-fin spine slightly shorter than the second dorsal-fin spine (vs. third spine markedly shorter than second spine), 1 or 2 prominent pale brown to dark brown blotches on the membrane between the fifth to eighth or sixth to ninth dorsal-fin spines (vs. 1 blotch on the membrane around the third dorsal-fin spine and 1 blotch on the membrane between the sixth to eighth dorsal-fin spines), and body with 11–15 longitudinal pale brown to dark brown bars along lateral line (vs. irregular brown specks). A key to the species of Ocosia is given.

Description of a new deep-water species of Heteroclinus (Pisces: Teleostei: Clinidae), from southern Australia

Heteroclinus argyrospilos, n. sp. is described as a new species from specimens sampled by sled and dredge in 55–100 m off South Australia and Western Australia. The species has a strongly compressed body and spatulate orbital tentacle similar to some shallow water species, particularly those of the Heteroclinus heptaeolus complex, which is characterized by having three segmented dorsal-fin rays, with the last two rays widely separate from the first ray. It is distinct from other Australian clinids in having two segmented dorsal-fin rays, well separated from the last dorsal-fin spine and a reduced lateral line on the body. It is known from a greater depth than other members of the genus.

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.

Regenerative Polarity of the Fin Ray in Zebrafish Caudal Fin and Related Tissue Formation on the Cut Surface

Zebrafish caudal fin rays are used as a model system for regeneration because of their high regenerative ability, but studies on the regeneration polarity of the fin ray are limited. To investigate this regeneration polarity, we made a hole to excise part of the fin ray and analyzed the regeneration process. We confirmed that the fin rays always regenerated from the proximal margin toward the distal margin, as previously reported; however, regeneration-related genes were expressed at both the proximal and distal edges of the hole in the early stage of regeneration, suggesting that the regenerative response also occurs at the distal edge. One difference between the proximal and distal margins is a sheet-like tissue that is formed on the apical side of the regenerated tissue at the proximal margin. This sheet-like tissue was not observed at the distal edge. To investigate whether the distal margin was also capable of forming this sheet-like tissue and subsequent regeneration, we kept the distal margin separated from the proximal margin by manipulation. Consequently, the sheet-like tissue was formed at the distal margin and regeneration of the fin ray was also induced. The regenerated fin rays from the distal margin protruded laterally from the caudal fin and then bent distally, and their ends showed the same characteristics as those of the normal fin rays. These results suggest that fin rays have an ability to regenerate in both directions; however, under normal conditions, regeneration is restricted to the proximal margin because the sheet-like tissue is preferentially formed on the apical side of the regenerating tissue from the proximal margin.

Garra hormuzensis, a new species from the upper Kol River drainage in the Persian Gulf basin (Teleostei: Cyprinidae)

Garra hormuzensis, new species, is described from the Kol River drainage. It is distinguished from its congeners in the Iranian part of the Persian Gulf basin by having 7½ branched dorsal-fin rays, usually 9+8 branched caudal-fin rays, the breast, belly and back in front of the dorsal-fin origin covered by scales, and a free lateral and posterior margins of the gular disc. It is further characterised by having a minimum K2P distance of 1.16% to G. mondica in the mtDNA COI barcode region.

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.

Osteoblasts pattern endothelium and somatosensory axons during zebrafish caudal fin organogenesis

Skeletal elements frequently associate with vasculature and somatosensory nerves, which regulate bone development and homeostasis. However, the deep, internal location of bones in many vertebrates has limited in vivo exploration of the neurovascular-bone relationship. Here, we use the zebrafish caudal fin, an optically accessible organ formed of repeating bony ray skeletal units, to determine the cellular relationship between nerves, bones, and endothelium. In adults, we establish the presence of somatosensory axons running through the inside of the bony fin rays, juxtaposed with osteoblasts on the inner hemiray surface. During development, we show the caudal fin progresses through sequential stages of endothelial plexus formation, bony ray addition, ray innervation, and endothelial remodeling. Surprisingly, the initial stages of fin morphogenesis proceed normally in animals lacking either fin endothelium or somatosensory nerves. Instead, we find that sp7+ osteoblasts are required for endothelial remodeling and somatosensory axon innervation in the developing fin. Overall, this study demonstrates that the proximal neurovascular-bone relationship in the adult caudal fin is established during fin organogenesis, and suggests that ray-associated osteoblasts pattern axons and endothelium.

Review of the cardinalfishes of the genus Cercamia (Percomorpha: Apogonidae) of the Red Sea and Indian Ocean with descriptions of three new species

The representatives of Cercamia from the Indian Ocean including Red Sea are reviewed and three new species are described: Cercamia spio n. sp., formerly known as C. eremia (Allen, 1987), is described from 14 specimens, 17–33 mm SL, collected in 10–15 meters from northern (Duba) to central (Jeddah) Saudi Arabia and from Jezirat Fara’un, Egypt. It also has been photographed from the Gulf of Aqaba (Dahab, Egypt) and El Quseir (Mangrove Bay, Egypt). The new species is distinguished from other Indian Ocean Cercamia in having fewer developed gill rakers on lower limb (usually 11 versus usually 12–13) and fewer anal-fin rays (11 versus usually 12–13). Another new species, Cercamia laamu, n. sp., is described only from the Maldives and Chagos Archipelago based on five specimens 16.0–30.5 mm SL. It differs from all Indian Ocean Cercamia in having more greater number of the second dorsal-fin rays (10 versus usually 9), and a translucent body devoid of reddish marks versus small reddish dots and crisscross lines. The third new species, Cercamia mascarene, n. sp., is described from 40 specimens 19–36 mm SL, from Rodrigues Island, Mauritius. It differs from Cercamia eremia in having a greater number of developed gill rakers on the lower limb of the first gill arch (usually 13 versus usually 12). Free neuromasts and cephalic pores are illustrated for Cercamia mascarene and free neuromasts on the body and caudal fin are illustrated for Japanese specimens of C. cf. eremia. New diagnoses are provided for Cercamia cladara, the type species of the genus, and C. eremia. A map of collection locations for species of Cercamia is presented to show the breath of known occurrences in the Red Sea and Indian Ocean. A new morphologic diagnosis is provided for Cercamia. A phylogenetic analysis of the barcoding portion of the mitochondrial COI gene, including all available sequences from members of the genus Cercamia, displays a much higher species diversity than expected, with high levels of divergence among recognized and undescribed species. A key to the described Indian Ocean species is provided.

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.