scholarly journals Length-weight relationships of four finfish commercial species from the southern Gulf of Mexico

2021 ◽  
Vol 49 (2) ◽  
pp. 369-375
Author(s):  
Iván Velázquez-Abunader ◽  
Thierry Brulé ◽  
Miguel A. A. Cabrera ◽  
Jorge A. A. López-Rocha
Keyword(s):  
Gulf Of Mexico ◽  
Stock Assessment ◽  
The Other ◽  
Small Scale ◽  
Allometric Growth ◽  
Mycteroperca Bonaci ◽  
Commercial Species ◽  
Southern Gulf Of Mexico ◽  
Important Input ◽  
The Relationship

The relationship between total length and total weight (LWR) of four commercial species of finfish captured in the southern Gulf of Mexico (Lachnolaimus maximus, Ocyurus chrysurus, Mycteroperca bonaci, and Mycteroperca microlepis) was estimated. Two of these species are captured in the region by the small-scale fleet, while the other two are targeted by small-scale and semi-industrial fleets using harpoons, handlines, and long-lines. For the assessment, the organisms were sampled at the landing decks in the study area in two periods: 1996-1999 (semi-industrial fleet) and from April 2017 to May 2018 (small-scale fleet). A total of 2780 individuals were sampled which 2775 individuals were used to obtain LWR functions. The four species showed negative allometric growth with b < 3 for the 2017-2018 period, two species showed positive allometric growth with b > 3 for the 1996-1999 period. This type of information is an important input for the stock assessment of these species that support important fisheries in the zone and are under high fishing pressure levels.

Comparison between the feeding habits of spotted eagle ray (Aetobatus narinari) and their potential prey in the southern Gulf of Mexico

2018 ◽  
Vol 99 (3) ◽  
pp. 661-672 ◽  
Author(s):  
F. Serrano-Flores ◽  
J.C. Pérez-Jiménez ◽  
I. Méndez-Loeza ◽  
K. Bassos-Hull ◽  
M.J. Ajemian
Keyword(s):  
Gulf Of Mexico ◽  
Prey Species ◽  
Prey Availability ◽  
Feeding Habits ◽  
Small Scale ◽  
Potential Prey ◽  
Important Prey ◽  
Ecological Aspects ◽  
Southern Gulf Of Mexico ◽  
Spotted Eagle Ray

In the southern Gulf of Mexico, the spotted eagle ray (Aetobatus narinari) is the second most frequently caught batoid in small-scale fisheries off Campeche. Ecological aspects of this ray are unknown in this region, hampering the understanding of the relationship between its distribution and prey availability in the fishing area. In order to study the feeding habits of this batoid and characterize its potential prey in the study area, stomachs and intestines of 154 specimens (68 females and 86 males) were analysed. The results indicated that A. narinari near Campeche is a specialist and selective predator that feeds mainly on gastropods (92.7% IRI), with no significant differences in the diet found between sexes, size groups, or between stomach and intestine contents. In addition, the results indicated that the most important prey species in the diet were among the most common benthic species in three of the four sampling transects positioned in or adjacent to fishing areas for rays. These most important prey species were Strombus pugilis (53.33% IRI) and Americoliva reticularis (25.6% IRI). Other prey species included Lobatus costatus (5.6% IRI) and Petrochirus diogenes (3.6% IRI). This study suggests that this widely distributed ray species feeds in Campeche's coastal waters and that the study of its potential prey increases the understanding of ecological aspects of the species, which emphasizes the added importance of monitoring fishery impacts on prey species (e.g. the conch fishery off Campeche) to help support integrated assessment and management of fisheries.

scholarly journals The Geomorphic Evolution of the Lunar Surface

1972 ◽  
Vol 47 ◽  
pp. 43-54
Author(s):  
L. B. Ronca
Keyword(s):  
Lunar Surface ◽  
Monotonic Function ◽  
The Other ◽  
Small Scale ◽  
Fundamental Parameters ◽  
Considerable Length ◽  
Radiometric Ages ◽  
Two Parameters ◽  
Relationship Of ◽  
The Relationship

Fundamental parameters of the geomorphology of a lunar surface are (i) the number and size distribution of craters, (ii) the degree of erosion of the craters and (iii) thickness and other characteristics of the regolith. These parameters are not independent of one another; as one changes through time, the other two will also change in a statistically predictable way.In the continuous degradation sequence, the relationship between the number of craters per unit area and the degree of erosion of the craters is continuous and monotonic. This sequence occurs in areas subjected to intermediate to small impacts, and eroded mainly by the impacts themselves plus other small-scale erosional processes. In areas subjected to large impacts and mare flooding the discontinuous degradation sequence is predominant.The relationship of the first two parameters, the number of craters and the degree of erosion, with the third parameter, the regolith, is not simple and is not yet understood. It appears, however, that the geomorphological stage is more important than the mare-versus-highland dichotomy of the lunar surface.The solution of the function relating craters of the continuous degradation sequence with degree of erosion was defined as the geomorphic index of the area. Studies of the geomorphic index of stratigraphic surfaces show that areas covered by considerable ballistic sediments have a geomorphic index which is not a monotonic function of time. On the other hand, areas covered almost exclusively by mare flooding show an index which is a monotonic function of the age of the flooding. As each mare surface shows a considerable range in indices, it is concluded that maria are covered by surfaces formed through a considerable length of time. By using Apollo 11 and 12 radiometric ages it is suggested that the time of mare flooding lasted on the order of one billion (109) years.The geomorphic index of highland surfaces shows a remarkable degree of order; i.e., the farther an area is inland from the mare shores, the higher will be the index. No explanation is given to this phenomenon, but is suggested that lunar erosion is not just a localized phenomenon centered on the locus of an impact, but has lateral trends of regional dimensions. Electrostatic transportation as suggested by Gold is a possible mechanism.

The relationship between zooplankton distribution and hydrography in oceanic waters of the Southern Gulf of Mexico

2019 ◽  
Vol 192 ◽  
pp. 28-41 ◽  
Author(s):  
J. Färber Lorda ◽  
G. Athié ◽  
V. Camacho Ibar ◽  
L.W. Daessle ◽  
O. Molina
Keyword(s):  
Gulf Of Mexico ◽  
Zooplankton Distribution ◽  
Southern Gulf Of Mexico ◽  
The Relationship

scholarly journals Length-weight relationship and condition factor of the mangrove crab Ucides cordatus (Linnaeus, 1763) (Crustacea, Brachyura, Ucididae)

2009 ◽  
Vol 52 (2) ◽  
pp. 397-406 ◽  
Author(s):  
Marcelo Antonio Amaro Pinheiro ◽  
Ana Gláucia Fiscarelli
Keyword(s):  
Condition Factor ◽  
The Other ◽  
Allometric Growth ◽  
Ucides Cordatus ◽  
Mangrove Crab ◽  
Wet Weight ◽  
The Mean ◽  
Autumn And Winter ◽  
Relationship Of ◽  
The Relationship

The relationship of wet weight (WT) to cephalothorax width (CW) and temporal and seasonal variations in the condition factor were analyzed for each sex of the mangrove crab Ucides cordatus, using specimens collected monthly from September 1998 through September 2000, at Iguape, state of São Paulo. The WT/CW relationship, determined by the regression analysis and the condition factor were evaluated individually, monthly and seasonally, for each sex. The WT/CW relationship indicated isometric growth in males and negative allometric growth in females. Body weight was higher in males than in females of equivalent size and this difference was associated with the males' faster growth and heavier chelipeds. On the other hand, the means for condition factor were always higher for females than for males; the mean condition factor was lower in spring and summer and higher in autumn and winter.

scholarly journals Relationships between fish larvae and siphonophores in the water column: effect of wind-induced turbulence and thermocline depth

2007 ◽  
Vol 64 (5) ◽  
pp. 878-888 ◽  
Author(s):  
L. Sanvicente-Añorve ◽  
M. A. Alatorre ◽  
C. Flores-Coto ◽  
C. Alba
Keyword(s):  
Water Column ◽  
Fish Larvae ◽  
Distribution Patterns ◽  
Small Scale ◽  
Thermocline Depth ◽  
Contact Rates ◽  
Southern Gulf Of Mexico ◽  
High Degree ◽  
The Relationship ◽  
Sufficient Strength

Abstract Sanvicente-Añorve, L., Alatorre, M. A., Flores-Coto, C., and Alba, C. 2007. Relationships between fish larvae and siphonophores in the water column: effect of wind-induced turbulence and thermocline depth. – ICES Journal of Marine Science, 64: 878–888. The relationship between the abundance of fish larvae and siphonophores in relation to wind-induced turbulence and thickness of the mixed layer in the southern Gulf of Mexico were studied during two periods of different wind conditions: April (5.25 m s−1) and October (6.5 m s−1). The Spearman correlation between fish larvae and siphonophores revealed a random relationship in the 0–10 m layer during April and in the 0–20 m layer in October. This structure presumably persists while turbulent forces remain at sufficient strength. Positive patterns were observed deeper in the water column. Whereas thermocline position did not correspond with the depth separating random and positive relationships, low turbulence values did. Observations indicate that turbulent kinetic energy values above 4 × 10−4 J kg−1 might promote a random distribution between potential prey and predator zooplankton taxa. In surface waters, contact rates between siphonophores and fish larvae showed that turbulence enhances encounters 2.5 (1.2) times in April and 3.3 (1.3) times in October for prey velocities of 0.003 (0.011) m s−1. The positive relationship between fish larvae and siphonophores could be caused by a high degree of spatial overlap, enough food for both groups, and limited predation on larvae in the presence of alternative prey. Seasonal variability in the vertical structure of distribution patterns was attributed mainly to aggregative feeding behaviour of organisms and disruption of patches as a consequence of small-scale water turbulence.

scholarly journals Eyeless morphotype in the southern stingray (Dasyatis americana): a non-lethal and frequent abnormality from the southern Gulf of Mexico

2017 ◽  
Vol 44 (3) ◽  
pp. 460-469
Author(s):  
Manuel Mendoza-Carranza ◽  
Diego Santiago-Alarcón ◽  
Juan Carlos Pérez-Jiménez ◽  
Chrystian Carolina Hernández-Lazo
Keyword(s):  
Gulf Of Mexico ◽  
Morphological Characters ◽  
Mature Female ◽  
Conclusive Evidence ◽  
Small Scale ◽  
Phenotypic Traits ◽  
Coastal Zones ◽  
Bar Code ◽  
Southern Gulf Of Mexico ◽  
Close Relatives

Elasmobranchs are active predators that depend on a highly developed visual system. The eyes of the southern stingray, Dasyatis americana, are adapted to a changing light environment in coastal zones. In this study we use morphological characters and molecular methods (mtDNA COI) to describe an eyeless morphotype of D. americana from six individuals collected from commercial small-scale fisheries on the Campeche Bank (southern Gulf of Mexico). Additionally to the eyeless characteristic, both regular (presence of eye) and eyeless (absence of eye) morphotypes have contrasting quantitative values and qualitative features for different phenotypic traits (color, teeth number, pelvic fin and spiracle form). Mature female and male eyeless morphotype had functional internal reproductive structures. Using the bar code gene, we found conclusive evidence that the eyeless morphotype belongs to the species D. americana. This is the first report on reproductively functional eyeless individuals of this species or close relatives elsewhere, which live sympatrically with regular D. americana individuals in the southern Gulf of Mexico

The Relationship Between Suicidal Thinking and Dating Violence in a Sample of Adolescent Abortion Patients

Crisis ◽  
2011 ◽  
Vol 32 (5) ◽  
pp. 246-253 ◽  
Author(s):  
Gretchen E. Ely ◽  
William R. Nugent ◽  
Julie Cerel ◽  
Mholi Vimbba
Keyword(s):  
Unintended Pregnancy ◽  
Dating Violence ◽  
Young Women ◽  
Psychosocial Problems ◽  
The Other ◽  
Assessment Scale ◽  
Adolescent Dating Violence ◽  
Adolescent Relationships ◽  
Suicidal Thinking ◽  
The Relationship

Background: The relationship between suicidal thinking and adolescent dating violence has not been previously explored in a sample of adolescent abortion patients. Aims: This paper highlights a study where the relationship between dating violence and severity of suicidal thinking was examined in a sample of 120 young women ages 14–21 seeking to terminate an unintended pregnancy. Methods: The Multidimensional Adolescent Assessment Scale and the Conflict in Adolescent Relationships Scale was used to gather information about psychosocial problems and dating violence so that the relationship between the two problems could be examined, while controlling for the other psychosocial problems. Results: The results suggest that dating violence was related to severity of suicidal thinking, and that the magnitude of this relationship was moderated by the severity of problems with aggression. Conclusions: Specifically, as the severity of participant’s general problems with aggression increased, the magnitude of the relationship between dating violence and severity of suicidal thinking increased. Limitations of the study and implications for practice are discussed.

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