Sea cucumber body wall contains several naturally occurring bioactive components that possess health-promoting properties. Isostichopus badionotus from Yucatan, Mexico is heavily fished, but little is known about its bioactive constituents. We previously established that I. badionotus meal had potent anti-inflammatory properties in vivo. We have now screened some of its constituents for anti-inflammatory activity in vitro. Glycosaminoglycan and soluble protein preparations reduced 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammatory responses in HaCaT cells while an ethanol extract had a limited effect. The primary glycosaminoglycan (fucosylated chondroitin sulfate; FCS) was purified and tested for anti-inflammatory activity in vivo. FCS modulated the expression of critical genes, including NF-ĸB, TNFα, iNOS, and COX-2, and attenuated inflammation and tissue damage caused by TPA in a mouse ear inflammation model. It also mitigated colonic colitis caused in mice by dextran sodium sulfate. FCS from I. badionotus of the Yucatan Peninsula thus had strong anti-inflammatory properties in vivo.
Based on their morphological and genetic similarity, several studies have proposed that Lutjanus campechanus and Lutjanus purpureus are the same species, but there is no confirmed consensus yet. A population-based study concerning otolith shape and genetic analyses was used to evaluate if L. campechanus and L. purpureus are the same species. Samples were collected from populations in the southwestern Gulf of Mexico and the Venezuelan Caribbean. Otolith shape was evaluated by traditional and outline-based geometric morphometrics. Genetic characterization was performed by sequencing the mtDNA control region and intron 8 of the nuclear gene FASD2. The otolith shape analysis did not indicate differences between species. A nested PERMANOVA identified differences in otolith shape for the nested population factor (fishing area) in morphometrics and shape indexes (p = 0.001) and otolith contour (WLT4 anterior zone, p = 0.005 and WLT4 posterodorsal zone, p = 0.002). An AMOVA found the genetic variation between geographic regions to be 10%, while intrapopulation variation was 90%. Network analysis identified an important connection between haplotypes from different regions. A phylogenetic analysis identified a monophyletic group formed by L. campechanus and L. purpureus, suggesting insufficient evolutionary distances between them. Both otolith shape and molecular analyses identified differences, not between the L. campechanus and L. purpureus species, but among their populations, suggesting that western Atlantic red snappers are experiencing a speciation process.
Aims: We studied the regeneration dynamics of woodlands and abandoned old fields in a landscape dominated by Quercus suber in its lower limits of rainfall and temperature. Two hypotheses were established: (1) regeneration of Quercus species is strongly favored by the presence of tree cover; and (2) growth of Q. suber is driven by the climatic variables that represent the lower ecological limit of its leading distribution edge. Methods: We selected woodlands and old fields with and without tree remnants (n = 3 per type), and analyzed stand structure, soil parameters and tree growth. Results: Succession was arrested in old fields without tree remnants. By contrast, remnant trees were accelerators of forest recovery in old fields. Tree cover played a fundamental role in Quercus recruitment throughout seed dispersal and facilitation that mitigate the effects of summer drought on seedlings. Also, tree cover improved soil parameters (e.g., organic matter) that are important factors for understanding differences in regeneration. Winter/spring precipitation exerted a positive effect on tree growth, as well as temperatures during winter/spring and September. Conclusions: Regeneration dynamics are modeled by the density of tree cover in the cold and dry edge of the distribution area of Q. suber where Q. ilex is increasing in abundance. Although temperature has a positive effect on the tree growth of Q. suber, when demographic processes are considered, decreases in water availability likely play a critical role in Q. ilex recruitment. This in turn changes dominance hierarchies, especially in abandoned areas with little or no tree cover.
It has previously been shown that epilithic bacterial biopolymers used as coatings influenced the physical properties (surface hardness and color change) at different levels and decreased the surface disaggregation of experimental limestone when evaluated at the laboratory level. A short-term study (30 days) was conducted to evaluate the performance under natural conditions of limestone blocks exposed to tropical conditions of a selected bacterial biopolymer (TM1B-488, after the producing bacterium) and a previously unreported Mayan plant biopolymer known as “Escobilla”, Sida rhombifolia (Malvaceae) used in conservation procedures. Surface hardness (Leeb units) and color (L*a*b* coordinates) were measured and statistically tested for two types of limestone blocks (sound and deteriorated limestone). Both biopolymers increased surface hardness, decreased surface disaggregation, and did not alter color. Escobilla polymer is a carbohydrate-rich biopolymer characterized by tangential filtration, global chemical composition, and monosaccharide composition of hydrolyzed polymer. These results indicate that biopolymers of a heteropolysaccharide nature are constituted by some anionic charge residues that could contribute to surface stabilization and consolidation, but compatibility with traditional building materials (mortars) and longer time of exposure (a year) are necessary to fully assess their applicability in the restoration of architectural heritage.
Studies of fish reproductive biology often involve quantitative estimates based on histological sections of the ovaries. Prior characterization of gonad oocyte distribution patterns in females is fundamental to these studies. Heterogeneous distribution requires a standardized sampling protocol to prevent bias in data such as fecundity estimations. In contrast, homogeneous distribution allows sampling of any portion of the gonads with no risk of bias. A preliminary study was done of gonad oocyte distribution mode in a hogfish Lachnolaimus maximus population in the southern Gulf of Mexico. A total of 23 sexually-active females were selected and classified by reproductive stage. Six histological sections were taken from the anterior, middle and posterior regions of the left and right ovary lobes of each individual. Digital image processing (AxioVision and Image ProPlus programs) was used to estimate oocyte density per unit area in different development stages. Contingency tables were used to analyze oocyte distribution frequencies between the regions of each lobe and between the lobes of each ovary. This was supported with a Pearson’s χ2 test for goodness-of-fit and a replicated G test to confirm distribution heterogeneity. Oocyte type distribution was homogeneous in almost all the females regardless of ovary region or lobe. This was particularly the case for females in the actively spawning reproductive subphase. Females in this subphase are normally used to estimate batch fecundity in fish species such as L. maximus, which have asynchronous oocyte development and batch spawning. However, heterogeneity was present in tertiary vitellogenesis oocytes in the right lobe of females in the spawning capable reproductive phase. In these cases, it is preferable to take histological sections from any region of the left ovary lobe to ensure unbiased estimation of fecundity and adequate characterization of this species’ sexual cycle.
Due to their requirements, geothermal projects are often located near volcanic activity that, in the tropics, overlaps with or lies close to conservation areas. It is therefore important to assess the environmental impact of these projects on biodiversity. We evaluated the impacts of well-drilling activities on bird communities at a geothermal field in Costa Rica. We hypothesized that (i) disturbance generated during drilling caused a temporary decline in bird diversity and abundance, followed by recovery once drilling noise ceased, and (ii) responses were species-specific, ranging from a negative response to neutral tolerance. Linear transects were established, and birds were sampled before, during, and after well-drilling. Our study revealed a moderate and transient impact during drilling operations. Analysis of diversity metrics showed lower values during drilling in only one case, which returned to pre-drilling levels once operations concluded. Individual responses were shaped by specific ecological traits—species tolerant of human disturbance and those with loud vocalizations showed greater adaptability, whereas species sensitive to acoustic masking, particularly duetting songbirds, were most affected. Nonetheless, noise control should not be addressed in isolation, especially in landscapes where conservation-priority species depend on critical resources such as forest remnants and suitable nesting trees. Analysis of community abundance and most of diversity metrics showed lower, although not significantly different, values during drilling, both of which returned to pre-drilling levels once operations concluded.