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

2021 ◽  
Vol 61 ◽  
pp. e20216174
Author(s):  
Thaís Isabela Carvalho ◽  
Julia Klaczko ◽  
Veronica Slobodian
Keyword(s):  
Delivery System ◽  
Cell Morphology ◽  
Leading Edge ◽  
Valid Species ◽  
Pectoral Girdle ◽  
Pectoral Fin ◽  
Histological Sections ◽  
Venomous Animals ◽  
Venom Glands ◽  
Axillary Region

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.

A new species of Osteobrama (Teleostei: Cyprinidae) from the Mahanadi River, India with a note on the validity of O. dayi

Zootaxa ◽  
2020 ◽  
Vol 4722 (1) ◽  
pp. 68-76
Author(s):  
BUNGDON SHANGNINGAM ◽  
SHIBANANDA RATH ◽  
ASHA KIRAN TUDU ◽  
LAISHRAM KOSYGIN
Keyword(s):  
New Species ◽  
Valid Species ◽  
Pectoral Fin ◽  
Mahanadi River ◽  
Dorsal Fin ◽  
Fin Rays ◽  
The Status ◽  
A New Species ◽  
Pectoral Fin Rays

A new species of the genus Osteobrama is described from the Mahanadi River, Tikarpada, Angul District, Odisha state, India. Osteobrama tikarpadaensis, new species, differs from its congeners in having two pairs of minute barbels; iii–iv unbranched dorsal-fin rays with 25–33 serrae on the last unbranched ray; 15–16 branched pectoral-fin rays, and 25–27 branched anal-fin rays. The status of Osteobrama dayi is discussed and shown to be a valid species. A key to the species of the genus is provided. 

Effect of pectoral fin kinematics on manta ray propulsion

2018 ◽  
Vol 32 (12n13) ◽  
pp. 1840025
Author(s):  
Hao Lu ◽  
Khoon Seng Yeo ◽  
Chee-Meng Chew
Keyword(s):  
Leading Edge ◽  
Wave Model ◽  
Pectoral Fin ◽  
Long Distance ◽  
Propulsive Efficiency ◽  
Fish Locomotion ◽  
Pectoral Fins ◽  
Flow Features ◽  
Edge Vortex ◽  
Manta Ray

Recent advancement of bio-inspired underwater vehicles has led to a growing interest in understanding the fluid mechanics of fish locomotion, which involves complex interaction between the deforming structure and its surrounding fluid. Unlike most natural swimmers that undulate their body and caudal fin, manta rays employ an oscillatory mode by flapping their large, flattened pectoral fins to swim forward. Such a lift-based mode can achieve a substantially high propulsive efficiency, which is beneficial to long-distance swimming. In this study, numerical simulations are carried out on a realistic manta ray model to investigate the effect of pectoral fin kinematics on the propulsive performance and flow structure. A traveling wave model, which relates a local deflection angle to radial and azimuthal wavelengths, is applied to generate the motion of the pectoral fins. Hydrodynamic forces and propulsive efficiency are reported for systematically varying kinematic parameters such as wave amplitude and wavelengths. Key flow features, including a leading edge vortex (LEV) that forms close to the tip of each pectoral fin, and a wake consisting of interconnected vortex rings, are identified. In addition, how different fin motions alter the LEV behavior and hence affect the thrust and efficiency is illustrated.

Validity of Lepadichthys misakius (Tanaka 1908) and redescription of Lepadichthys frenatus Waite 1904 (Gobiesocidae: Diademichthyinae)

Zootaxa ◽  
2019 ◽  
Vol 4551 (3) ◽  
pp. 275 ◽  
Author(s):  
KYOJI FUJIWARA ◽  
HIROYUKI MOTOMURA
Keyword(s):  
Morphological Changes ◽  
Lateral View ◽  
Valid Species ◽  
Pectoral Fin ◽  
Dorsal Fin ◽  
Posterior Nostril ◽  
Fin Ray ◽  
Fin Rays ◽  
Disc Size ◽  
Anterior Posterior

The clingfishes Lepadichthys frenatus Waite 1904 and Lepadichthys misakius (Tanaka 1908) are both redescribed as valid species, although the latter has previously been regarded as a junior synonym of the former. Lepadichthys frenatus and L. misakius are easily distinguished from their congeners by the following combination of characters: 14–19 dorsal-fin rays; 12–14 anal-fin rays; disc size moderate, its length 15.1–20.8 % of standard length (SL); and dorsal, anal and caudal fins connected by membranes. Lepadichthys misakius can be distinguished from L. frenatus by having 25–28 (modally 26 or 27) pectoral-fin rays [vs. 27–29 (29) in L. frenatus]; the upper end of the gill membrane level with the 5th to 8th (usually 6th) pectoral-fin ray base in lateral view [vs. 6th to 8th (7th)]; the lower 8th to 11th (9th) pectoral-fin ray base attached to the disc base by membrane [vs. 10th to 12th (11th)]; 7–11 (9) gill rakers on each arch [vs. 11–14 (12)]; anterior, posterior and least interorbital widths 9.0–11.8 (mean 10.7), 13.4–16.9 (15.3) and 3.2–8.8 (6.2) % SL, respectively [vs. 8.4–10.2 (9.4), 12.1–14.7 (13.5) and 2.8–5.9 (4.8) % SL, respectively]; and NC2 (nasal canal pore) usually located between the anterior and posterior margins of the posterior nostril (vs. usually located before the posterior nostril anterior margin). Morphological changes with growth of the two species are described in detail and a lectotype designated for L. frenatus. 

scholarly journals Review of the Brazilian species of Physiculus (Gadiformes: Moridae), with description of a new species from Saint Peter and Saint Paul Archipelago, equatorial Atlantic

Zootaxa ◽  
2019 ◽  
Vol 4671 (1) ◽  
pp. 67-80 ◽  
Author(s):  
ALESSANDRA M. A. PIRES ◽  
ALFREDO CARVALHO-FILHO ◽  
RÔMULO C. P. FERREIRA ◽  
DANIELLE VIANA ◽  
DIOGO NUNES ◽  
...  
Keyword(s):  
New Species ◽  
Saint Paul ◽  
Valid Species ◽  
Equatorial Atlantic ◽  
Pectoral Fin ◽  
Dorsal Fin ◽  
Brazilian Species ◽  
Fin Rays ◽  
Saint Peter ◽  
Pectoral Fin Rays

Three valid species of the genus Physiculus are known from the Brazilian marinewaters. A fourth, new species, Physiculus cirm n. sp.., is described based on seventeen specimens collected in the surroundings of Saint Peter and Saint Paul Archipelago, equatorial Atlantic. A review of the Brazilian species of Physiculus is provided, as well as a key to the species of the genus reported from the Atlantic Ocean. The new species is distinguished from all its congeners, except P. cynodon and P. karrerae, by the large number of longitudinal series of scales (156–189 vs. 70–150). P. cynodon from the Northern Pacific has about 200 longitudinal series of scales, and it differs from the new species by the number of rays of the first dorsal fin (6–8 vs. 10 in P. cynodon), pectoral-fin rays (20–25 vs. 27 in P. cynodon), and the presence of an outer row of large canine teeth on upper and lower jaw. From P. karrerae, which has 134–160 longitudinal series of scales, the new species differs by the presence of scales on the tip of the snout and dorsal-fin membrane, and the number of pectoral-fin rays (20–25 vs. 24–27 in P. karrerae). [Zoobank URL: urn:lsid:zoobank.org:act:1AFBC251-2BB1-4479-98A4-307188EC5D66] 

Investigating the effects of leading-edge tubercles on the aerodynamic performance of insect-like flapping wing

2020 ◽  
pp. 095440622094635
Author(s):  
Muhammad Bilal Anwar ◽  
Aamer Shahzad ◽  
Muhammad Nafees Mumtaz Qadri
Keyword(s):  
Leading Edge ◽  
Aerodynamic Performance ◽  
Flapping Wing ◽  
Chord Length ◽  
Humpback Whales ◽  
Power Coefficient ◽  
Pectoral Fin ◽  
Aerodynamic Efficiency ◽  
Potential Benefits ◽  
Better Than

Tubercles are small protuberances or bumps on the leading edge of humpback whale's pectoral fin. To examine the effects of leading-edge tubercles on the aerodynamic performance of a flapping wing, lift, drag, and power coefficients are obtained from numerical simulations. A revolving wing (one-degree-of-freedom azimuth rotation; rotation in a horizontal plane after an initial acceleration) with leading-edge tubercles at an angle of attack of 40° and Reynolds number of 400 is used in the present study. The reason for choosing azimuth rotation is that it resembles downstroke and upstroke of flapping motion of an insect. A rigid rectangular wing with six different combinations of wavelengths ( λ = 10% and 50% of the chord length) and amplitudes ( A = 2.5%, 5%, and 10% of the chord length) are chosen for this study. These parameters are inspired by the tubercles present at the leading edge of humpback whales' pectoral fin. It was observed that generally, tubercles degraded the aerodynamic performance of the wings in terms of lift, drag, and power coefficients. Although some of the tubercle leading-edge wings showed lower drag (2.20% lower) and lower power coefficient (2.12% lower) values than the baseline wing, none of the tubercle wing performed better than the baseline wing in terms of aerodynamic performance parameters; aerodynamic efficiency ([Formula: see text]) and power economy ([Formula: see text]). Hence, it was concluded that the tubercles are not advantageous over the straight leading-edge wing for azimuth rotating hovering insect-like motion and further investigation is required to explore its potential benefits.

Redescription of Brachirus aspilos (Bleeker 1852), a senior synonym of four nominal species, with a note on the distribution of Dagetichthys marginatus (Boulenger 1900) (Pleuronectiformes: Soleidae)

Zootaxa ◽  
2021 ◽  
Vol 4908 (3) ◽  
pp. 354-368
Author(s):  
JO OKAMOTO ◽  
HIROYUKI MOTOMURA
Keyword(s):  
Lateral Line ◽  
Valid Species ◽  
Nominal Species ◽  
Blind Side ◽  
Pectoral Fin ◽  
Type Specimens ◽  
Body Depth ◽  
Ocular Side ◽  
Fin Rays ◽  
Pelvic Fin

The poorly known sole Brachirus aspilos (Bleeker 1852) is redescribed on the basis of the holotype and 48 non-type specimens from Japan, Taiwan, Philippine, Singapore, Indonesia, Papua New Guinea, and Australia. The species is characterized by the following combination of characters: dorsal-fin rays 64–76 (mode 71), anal-fin rays 51–62 (56), pored scales on straight portion of lateral line 93–126 (118); vertebrae 41–44 (43); pectoral-fin rays 4–7 (6) and 4–7 (5) on ocular and blind sides, respectively; pelvic-fin rays 4–6 (5) and 4–5 (4) on ocular and blind sides, respectively; caudal-fin rays 13–15 (14); body slightly elongate, its depth 40.0–51.0 (mean 45.5)% SL; head length 16.1–23.9 (18.6)% SL; pectoral fin on ocular side longer than that on blind side, 5.3–7.6 (6.6)% SL and 4.0–6.0 (4.8)% SL, respectively; pelvic fin on ocular side longer than that on blind side, 4.9–7.4 (6.0)% SL and 4.3–7.5 (5.8)% SL, respectively; body depth below lateral line 21.7–27.1 (23.4)% SL; lips without labial papillae; eyes separated by scaled interorbital space; cycloid or weakly ctenoid scales on blind side; body on ocular side uniformly brown or grey with dark vermiculation, some small white blotches along dorsal- and anal-fin bases, or without remarkable pattern. Brachirus dicholepis (Peters 1877), B. heterolepis (Bleeker 1856), B. marmoratus (Bleeker 1853), and B. sorsogonensis (Evermann & Seale 1907), previously regarded as valid species, are all regarded as junior synonyms of B. aspilos. In addition, specimens previously reported as Dagetichthys marginatus (Boulenger 1900) from the western Pacific Ocean are re-identified as B. aspilos, the former species being considered restricted to South African waters. 

scholarly journals Pectoral Dimorphism Is a Pervasive Feature of Skate Diversity and Offers Insight into their Evolution

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
C M Martinez ◽  
B H Kao ◽  
J S Sparks ◽  
P C Wainwright
Keyword(s):  
Sexual Dimorphism ◽  
Shape Change ◽  
Skeletal Development ◽  
Interspecific Variation ◽  
Valid Species ◽  
Unique Form ◽  
Pectoral Fin ◽  
Male Specific ◽  
Insight Into

Synopsis Mature skates (Batoidea: Rajoidei) display a unique form of sexual dimorphism in which males develop a concave anterior pectoral fin, giving them a bell-shaped appearance. Recent work has linked the male-specific transformation to differential skeletal development that is coincident with the rapid elongation of claspers, cartilage-supported intromittent organs. Still, little is known about the prevalence of pectoral dimorphism across skates or of interspecific variation in its expression. Here, we use various morphological approaches to broadly explore pectoral dimorphism in skates, with the goal of understanding its significance in their evolutionary history. We find that pectoral fin sexual dimorphism exists across skate diversity, positively identifying its presence in at least 131 species spanning 33 genera, approximately 40% of valid species. Further, we show that the nature of male–female shape change is largely consistent across species, but that it differs in its magnitude at a biologically meaningful scale. Finally, we use the pygmy skate Fenestraja plutonia as a case study to illustrate ontogenetic patterns in the development of pectoral fin dimorphism, additionally identifying sex-based differences in the pelvic girdle and jaw. Our work suggests that the diversity of pectoral dimorphism in skates is linked to comparative growth and maturation, and potentially to processes underlying reproductive and life history diversification within the group.

scholarly journals PSII-20 Effect of mixing of extended boar semen using a bulk semen delivery system after 2 and 5 days in storage

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 234-234
Author(s):  
Kayla M Mills ◽  
Tabitha Steckler ◽  
Megan Bock ◽  
Amanda M Minton ◽  
Steve Terlouw ◽  
...  
Keyword(s):  
Delivery System ◽  
Cell Morphology ◽  
Sperm Cell ◽  
Semen Quality ◽  
Delivery Systems ◽  
Normal Morphology ◽  
Minimal Impact ◽  
Linear Decrease ◽  
Boar Semen

Abstract With the increase in utilization of bulk semen delivery systems, the objective of this study was to determine whether differences in semen quality exist from mixing stored bulk semen. Semen with motility and normal morphology >75% were used to create 4, 70-dose and 4, 35-dose bulk semen bags. Semen was cooled and transported 235 miles. On d2 or d5, a bag was mixed and hung for 15 min. Doses were removed every 2 minutes. One 70-dose (70M) and one 35-dose bag (35M) were mixed every 5th dose, while the remaining 70-dose (70NM) and 35-dose (35NM) bags were not mixed. Doses were weighed and analyzed for concentration using CASA and agglutination assessed. Every 5th dose was warmed and evaluated for motility. One milliliter of semen from the 5th dose was preserved and evaluated for sperm cell morphology. Doses averaged 0.04 ± 0.0001 x 109/mL cells in 31.5 ± 0.077 mL resulting in 1.26 billion sperm/dose. All bags averaged >80% motility on d2 and 69% on d5 with >90% normal morphology on both days. There were minor differences in concentration and normal morphology from variation in preparing bags, not associated with mixing. On d2, mixing had no significant effects on agglutination or motility (P > 0.05). Concentration differed between 35M and 35NM (0.0385 ± 0.0004 vs 0.0417 ± 0.0002 x 109/mL; P < 0.001), with no identifiable trend. On d5, mixing had no effects on concentration, normal morphology or agglutination (P > 0.05). Bag 70M had more distal droplets compared with 70NM (3.78 ± 0.31 vs 2.36 ± 0.34%; P = 0.023). There was a non-significant linear decrease in concentration in the 70NM and 35NM bags, where concentration decreased by 0.124 x109 cells. Mixing alleviated this reduction in the 35-dose bags and partially alleviated it in the 70-dose bags. These data demonstrate that mixing had minimal impact on semen quality and was able to mitigate the decrease in concentration in the 35-dose bag.

scholarly journals Local Myo9b RhoGAP activity regulates cell motility

2020 ◽  
pp. jbc.RA120.013623
Author(s):  
Sandra Angela Hemkemeyer ◽  
Veith Vollmer ◽  
Vera Schwarz ◽  
Birgit Lohmann ◽  
Ulrike Honnert ◽  
...  
Keyword(s):  
Cell Migration ◽  
Cell Motility ◽  
Cell Morphology ◽  
Actin Polymerization ◽  
Rho Gtpase ◽  
Leading Edge ◽  
Cell Extension ◽  
Local Inhibition ◽  
And Migration ◽  
Directional Cell Migration

To migrate, cells assume a polarized morphology, extending forward with a leading edge with their trailing edge retracting back toward the cell body. Both cell extension and retraction critically depend on the organization and dynamics of the actin cytoskeleton, and the small, monomeric GTPases Rac and Rho are important regulators of actin. Activation of Rac induces actin polymerization and cell extension whereas activation of Rho enhances acto-myosin II contractility and cell retraction. To coordinate migration, these processes must be carefully regulated. The myosin Myo9b, a Rho GTPase activating protein (GAP), negatively regulates Rho activity and deletion of Myo9b in leukocytes impairs cell migration through increased Rho activity. However, it is not known whether cell motility is regulated by global or local inhibition of Rho activity by Myo9b. Here, we addressed this question by using Myo9b-deficient macrophage-like cells that expressed different recombinant Myo9b constructs. We found that Myo9b accumulates in lamellipodial extensions generated by Rac-induced actin polymerization as a function of its motor activity. Deletion of Myo9b in HL-60 derived macrophages altered cell morphology and impaired cell migration. Reintroduction of Myo9b or Myo9b motor and GAP mutants revealed that local GAP activity rescues cell morphology and migration. In summary, Rac activation leads to actin polymerization and recruitment of Myo9b, which locally inhibits Rho activity to enhance directional cell migration. In summary, Rac activation leads to actin polymerization and recruitment of Myo9b, which locally inhibits Rho activity to enhance directional cell migration.

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