gill rakers
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Zootaxa ◽  
2022 ◽  
Vol 5091 (3) ◽  
pp. 37-50
Author(s):  
SIRIKANYA CHUNGTHANAWONG ◽  
HIROYUKI MOTOMURA

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.  


2021 ◽  
Author(s):  
Shu‐Lin Tang ◽  
Xu‐Fang Liang ◽  
Yuye Wang ◽  
Jiao Li ◽  
Zhilu Zhang

2021 ◽  
Vol 937 (2) ◽  
pp. 022061
Author(s):  
V. Shatalin ◽  
I.W. Moryzi ◽  
E.W. Pishchenko ◽  
A. Rostovtsev

Abstract The morphological structure, size-age variability and dynamics of age-related fertility of producers of Baikal omul of pelagic, near-bottom and coastal morpho-ecological groups during the depressive state of the population were studied. There is an improvement in the indicators of the growth rate of fish, maturation and an increase in absolute individual fertility against the background of the dilution of the population and the release of the feeding area. A comparative characteristic of some morphological features of fish among morphological-ecological groups is given. The number of gill rakers on the first gill arch significantly distinguishes different morpho-ecological groups and ranges from 36 to 43 pieces for the near-bottom, from 40 to 46 pieces for the coastal and from 44 to 53 pieces for the pelagic morpho-ecological groups. It is noted that the spawning populations of the coastal and pelagic groups are mainly represented by young individuals. With age, the proportion of females increases in all groups. The largest indices of the pectoral, abdominal and anal fins, responsible for movement in the vertical plane, rotation and stop, are noted in the near-bottom group.


Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1439
Author(s):  
Joseph P. Nowlan ◽  
Scott R. Britney ◽  
John S. Lumsden ◽  
Spencer Russell

There is a limited understanding of the pathogenesis of tenacibaculosis in Atlantic salmon (Salmo salar L.) and there are few reproducible exposure models for comparison. Atlantic salmon were exposed via bath to Tenacibaculum maritimum, T. dicentrarchi, or T. finnmarkense, and were then grouped with naïve cohabitants. Mortalities had exaggerated clinical signs of mouthrot, a presentation of tenacibaculosis characterized by epidermal ulceration and yellow plaques, on the mouth and less frequently on other tissues. Histopathology showed tissue spongiosis, erosion, ulceration, and necrosis ranging from mild to marked, locally to regionally extensive with mats of intralesional bacteria on the rostrum, vomer, gill rakers, gill filaments, and body surface. Exposure to T. maritimum resulted in less than a 0.4 probability of survival for both exposed and cohabitants until Day 21. Exposures to T. dicentrarchi resulted in 0 and 0.55 (exposed), and 0.8 and 0.9 (cohabitant) probability of survival to Day 12 post-exposure, while T. finnmarkense had a 0.9 probability of survival to Day 12 for all groups. This experimental infection model will be useful to further investigate the pathogenesis of tenacibaculosis, its treatment, and immunity to Tenacibaculum species.


Zootaxa ◽  
2021 ◽  
Vol 5052 (1) ◽  
pp. 105-116
Author(s):  
CHI-NGAI TANG

A new species of codling Physiculus megastomus sp. nov. is described based on the holotype and a subadult paratype collected from northern and eastern Taiwan. The new species is classified in Physiculus by the presence of a ventral light organ on the abdomen and a chin barbel, and the absence of vomerine teeth. It is distinguished from congeners in having a large mouth with the posterior end of the maxilla extending well behind the level of the posterior margin of the orbit, its length 57.8‒60.7% in head length (HL) and the combination of the following characters: both jaws bearing caniniform teeth; snout, suborbital area, and gular region fully scaled; ventral light organ small, its length 5.5‒6.7% of distance from the interventral line to the origin of the anal fin (InV-af), located approximately at the mid-point of InV-af; five gill rakers on the upper limb of the first gill arch. DNA barcoding supported the establishment of the new species.  


Zootaxa ◽  
2021 ◽  
Vol 5039 (3) ◽  
pp. 363-394
Author(s):  
THOMAS H. FRASER ◽  
SERGEY V. BOGORODSKY ◽  
AHMAD O. MAL ◽  
TILMAN J. ALPERMANN

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.  


2021 ◽  
pp. 4-7
Author(s):  
P. Vigneshwaran ◽  
S. Ravichandran

The first record of Mothocya arrosor Bruce, 1986 parasitizing ribbon halfbeak fish Euleptorhamphus viridis is here reported from the southeast coast of India. The important characters distinguishing M. arrosor from other species in the genus include the body slightly twisted to one side, dorsum weakly convex, coxae of pereonites 6 and 7 distinctly rounded, pleon more completely overlapped by pereonite 7, pleonite 1 scarcely visible in dorsal view, uropod peduncle longer than rami, lacking strongly convex medial and lateral margins. The damage of gill rakers and erosion of gill lamellae were the acute gross lesions observed as a result of isopod infestation.


Zootaxa ◽  
2021 ◽  
Vol 5004 (3) ◽  
pp. 481-489
Author(s):  
HARUTAKA HATA ◽  
HIROYUKI MOTOMURA

The new anchovy Stolephorus grandis n. sp., described on the basis of 10 specimens collected from Papua, Indonesia, and Australia, closely resembles Stolephorus mercurius Hata, Lavoué & Motomura, 2021, Stolephorus multibranchus Wongratana, 1987, and Stolephorus rex Jordan & Seale, 1926, all having double pigmented lines on the dorsum from the occiput to the dorsal-fin origin, a long maxilla (posterior tip just reaching or slightly beyond the posterior margin of preopercle), and lacking a predorsal scute. However, the new species clearly differs from the others in having fewer gill rakers (35–39 total gill rakers on the first gill arch in S. grandis vs. > 38 in the other species), a greater number of vertebrae (total vertebrae 42–43 vs. fewer than 41), longer caudal peduncle (21.9–23.7% SL vs. < 20.8%), and the depressed pelvic fin not reaching posteriorly to vertical through the dorsal fin-origin (vs. reaching beyond level of dorsal-fin origin).


Zootaxa ◽  
2021 ◽  
Vol 4975 (2) ◽  
pp. 389-396
Author(s):  
HARUTAKA HATA ◽  
HIROYUKI MOTOMURA

The new sardine Sardinella ventura n. sp. (Teleostei: Clupeiformes: Clupeidae) is described on the basis of 10 specimens collected from Mauritius. The new species is most similar to Sardinella dayi Regan 1917 in having non-deciduous scales with pores and discontinuous striae, a dark spot on the dorsal-fin origin, the pelvic fin with 8 rays, and similar number of gill rakers, in addition to very similar numbers of keeled scutes. However, the new species is distinguished from S. dayi by having a shorter caudal peduncle [6.2–7.6% SL (mean 7.0%) vs. 8.2–12.0% (9.2%) in S. dayi], larger eye [8.4–9.9% (9.0%) vs. 6.8–8.0% (7.4%)] and orbit [9.6–12.3% (10.7%) vs. 8.5–10.2% (9.3%)], longer pectoral [21.0–22.7% (21.5%) vs. 17.0–21.0% (19.8%)] and pelvic fins [12.5–13.5% (12.8%) vs. 10.4–12.2% (11.2%)], and a greater numbers of pseudobranchial filaments [17–19 (modally 17) vs. 18–22 (19)], lateral scale rows in longitudinal series [41–43 (41) vs. 38–42 (40)] and transverse scales [11 or 12 (12) vs. 11]. There were significant differences in seven meristic and 14 morphometric characters between the two species. 


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