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.

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.

New record of the Red Shoulder Wrasse, Stethojulis bandanensis (Bleeker, 1851) (Perciformes, Labridae), from Korea

A single female juvenile specimen of Stethojulis bandanensis (Bleeker, 1851) was collected from Korea. The specimen is characterized by the 14 pectoral fin rays, the orange-red spot on upper pectoral fin base, and two small light-blue-edged black dots on the caudal peduncle. This species is the third species of the genus Stethojulis Günther, 1861 in Korea, and the newly proposed Korean name for the species is “Ju-hwang-jeom-mu-ji-gae-nol-lae-gi”.

Two new species of snailfishes of the genus Careproctus (Cottoidei: Liparidae) from the western North Pacific Ocean with a range extension of Careproctus brevipectoralis

Three snailfish species of Careproctus (Cottoidei: Liparidae), including two new species, are described from the deep Pacific Ocean off northern Honshu Island, Japan. Careproctus cyanogladius sp. nov., collected from the depths of 2,698–3,223 m, can be distinguished from congeneric species by having the following combination of characters: vertebrae 63; dorsal-fin rays 57–58; anal-fin rays 50; principal caudal rays 7; pectoral-fin rays 29–31; pectoral fin without a notch; uppermost pectoral-fin base below a horizontal through posterior margin of maxillary; pelvic disk oval; chin pores well separated; teeth simple; pyloric caeca 6–10; body pale blue or gray when fresh. The other new species, Careproctus orri sp. nov., collected from depths of 640–808 m, can be distinguished from congeneric species by having the following combination of characters: vertebrae 58–60; dorsal-fin rays 52–53; anal-fin rays 47–49; pectoral-fin rays 34–35; pectoral fin with a distinct notch; cephalic pores 2-6-7-2, chin pores single, unpaired; gill slit extending ventrally to 5th or 6th pectoral-fin ray; teeth strongly trilobed; peritoneum dark, stomach white. In addition, one specimen of Careproctus brevipectoralis Chernova, Thiel & Eidus, 2020 was newly collected from Japan, and is redescribed here in detail with comments on intraspecific variations.

A new species of Trimma (Pisces: Gobiidae) from western Thailand, north-eastern Indian Ocean

A new species of Trimma is described from the islands just off the Thailand coast near Phuket. Trimma ukkriti n.sp. lacks scales on the cheek and opercle, but has ctenoid scales in the midline of the nape, has an elongate second spine of the first dorsal fin which reaches posteriorly to between the base of the spine and the base of the 4th ray of the second dorsal fin when adpressed, 19–20 pectoral-fin rays with 6–13 branched rays in the middle of the fin, an unbranched 5th pelvic-fin ray, which is 48–67% the length of the 4th ray, a U-shaped interorbital trench with no fleshy median ridge, a poorly developed postorbital trench ending at the 5th papilla in row p (which has 6 papillae in total), and row c beneath the eye consists of 6 papillae. When live and freshly collected, the species is very similar in appearance to T. okinawae and T. readerae, with orange to red spots on the head and body.

A new species of the cardinalfish genus Apogon (Teleostei, Apogonidae) from the southern Red Sea and Indian Ocean with comments on phylogenetic relationships within the Apogonini

Apogon fugax is described as a new species of cardinalfishes based on a specimen trawled off Jizan (Saudi Arabia), southern Red Sea, at a depth of 60–67 m; two specimens trawled off southwest of Ayeyarwady Delta, Myanmar, at 54–129 m; and two specimens trawled off Western Australia at 166 m. The new species shares characters with the modified ‘talboti look-alikes’ species group (i.e., A. caudicinctus, A. dianthus and A. soloriens) as well as A. rubrifuscus and A. deetsie (both previously also assigned to the latter species group) in having two supraneurals, 12 pectoral-fin rays (13 rays in A. soloriens), and an enlarged, membranous, ventral preopercular edge. Molecular phylogenetic analysis of the apogonid tribe Apogonini, however, revealed that A. fugax n. sp. and its most closely related congeners, A. deetsie and A. rubrifuscus, form a separate phylogenetic clade unrelated to that formed by the ‘talboti look-alikes’ species group that is part of the A. unicolor species group. Apogon fugax n. sp. is distinguished from the species of the ‘talboti look-alikes’ species group, A. deetsie and A. rubrifuscus, in having a large head (2.2–2.4 in SL versus 2.4–2.8 in SL), longer first dorsal-fin spine (1.7–2.0 versus 2.7–4.0 in length of the second spine), and in their gill rakers count (developed gill rakers on the first gill arch 11–12 versus 8–9 in A. soloriens and 13–20 in the other four species).

A new species from subtropical Brazil and evidence of multiple pelvic fin losses in catfishes of the genus Cambeva (Siluriformes, Trichomycteridae)

A third pelvic-less species of Cambeva from river basins draining the Geral mountain range in southern Brazil is described. It is distinguished from other congeners lacking pelvic fin and girdle, C. pascuali and C. tropeiro, by having six pectoral-fin rays, 20–23 dorsal procurrent caudal-fin rays, 15–20 opercular and 25–30 interopercular odontodes and a different colour pattern consisting of flank dark brownish-grey with two irregular horizontal rows of small pale yellow grey marks. Whereas available molecular evidence indicates that C. pascuali is more closely related to C. zonata, a species with well-developed pelvic fin, and C. tropeiro is more closely related to C. balios, another species also with well-developed pelvic fin; osteological data strongly suggest that the new species herein described is more closely related to C. diatropoporos than to other congeners. Therefore, this study indicates that the pelvic fin and pelvic-fin support have been lost independently in each of these three species of Cambeva, which corresponds to 11% of all describe species. This result highly contrasts with the closely-related trichomycterine genera Trichomycterus, in which only one in 50 species lost pelvic fin and girdle (0.2%) and Scleronema with all the nine included species having well-developed pelvic fin. These data suggest a stronger tendency to losing pelvic fin in Cambeva, but factors favouring this evolutionary event are still unknown.

Plectorhinchus makranensis (Teleostei, Haemulidae), a new species of sweetlips from the Persian Gulf and the Gulf of Oman

Plectorhinchus makranensissp. nov. is described on the basis of 16 specimens from the Persian Gulf and Gulf of Oman, in the Northwest Indian Ocean. The new species can be distinguished from congeners by a combination of dorsal fin rays XII, 18–20, pectoral-fin rays 16–17, tubed lateral-line scales 55–57, gill rakers count (10–12 on the upper limb and 16–17 on the lower limb), 17–18 scales between the lateral line and the first anal-fin spine, 30–31 circumpeduncular scale rows and color pattern. Plectorhinchus makranensissp. nov. is distinguished from P. schotaf by having the posterior margin of the opercular membrane grey (vs. red in P. schotaf), fewer circumpeduncular scale rows, and a shorter base of the soft portion of the dorsal fin, 27.6–29.4% of standard length (SL) (vs. 31–32.3% of SL in P. schotaf). The new species resembles P. sordidus but is differentiated from it by having more gill rakers, a smaller orbit diameter 27.5–32.1% of head length (HL) (vs. 35.5–37.2% of HL in P. sordidus), a longer caudal peduncle 19.2–21.3% of SL (vs. 17.1–17.9% of SL in P. sordidus), and the first to third pectoral-fin rays light gray (vs. dark gray in P. sordidus). The new species can also be distinguished from the other species, including P. schotaf and P. sordidus, based on COI and Cyt b molecular markers. The phylogenetic position of this new species indicates that it is a sister taxon of P. schotaf.

Anatomy and evolution of the pectoral filaments of threadfins (Polynemidae)

The most remarkable anatomical specialization of threadfins (Percomorphacea: Polynemidae) is the division of their pectoral fin into an upper, unmodified fin and a lower portion with rays highly modified into specialized filaments. Such filaments are usually elongate, free from interradial membrane, and move independently from the unmodified fin to explore the environment. The evolution of the pectoral filaments involved several morphological modifications herein detailed for the first time. The posterior articular facet of the coracoid greatly expands anteroventrally during development. Similar expansions occur in pectoral radials 3 and 4, with the former usually acquiring indentations with the surrounding bones and losing association with both rays and filaments. Whereas most percomorphs typically have four or five muscles serving the pectoral fin, adult polynemids have up to 11 independent divisions in the intrinsic pectoral musculature. The main adductor and abductor muscles masses of the pectoral system are completely divided into two muscle segments, each independently serving the pectoral-fin rays (dorsally) and the pectoral filaments (ventrally). Based on the innervation pattern and the discovery of terminal buds in the external surface of the filaments, we demonstrate for the first time that the pectoral filaments of threadfins have both tactile and gustatory functions.

Pomacentrus bangladeshius, a new species of damselfish (Perciformes, Pomacentridae) from Saint Martin’s Island, Bangladesh

A new species of damselfish, Pomacentrus bangladeshius, is described from 3 specimens, 67–77 mm standard length (SL), collected from Saint Martin’s Island, Bangladesh. The new species is distinguished from congeners in having the following combination of characters: XIV, 13 dorsal-fin elements; II, 14 anal-fin elements; 19 pectoral-fin rays; 18–19 lateral-line scales; 17–19 gill rakers on first arch; body depth 1.68–1.88 (1.88) in SL; snout 4.17–4.60 (4.17) in head length; head 2.91–3.09 (3.08) in SL; a prominent notch present between preorbital and suborbital; olive to dark brown body color, dark brown premaxilla, and yellow iris with a narrow bronze eye ring. The new species inhabits shallow reef flats around rock and coral outcrops. Phylogenetic analysis also shows the clear divergence of P. bangladeshius from other genetically closely related congeneric species retrieved from GenBank and that it represents a separate lineage.