Phylum Ctenophora: Amazing Bioluminescent Sea Animals

ana emilia-ctenoforo image 4Essay by Villasis-Peregrino I. & A.E. Ramos-Santiago (edited by Professor Krista Williams)

In the amazing world of marine animals, there are approximately one million animals. Among these animals are the bioluminescent ctenophores (also known as “comb jellies” or “sea walnuts”). The ctenophores are a phylum of marine planktonic invertebrates. In this essay we will talk about some characteristics of the ctenophores, such as their feeding, reproduction and ecological importance.

The ctenophores are natural predators: They have long tentacles with structures called coloblasts. The ctenophore’s tentacles extend, and when its prey touches the coloblasts, the tentacles discharge adhesive substances to catch their prey and discharge the stinging cells (Ruppert & Barnes 1996). After the ctenophore’s tentacles have caught its prey, muscular contractions direct the tentacles to its mouth. The mouth of the ctenophores gives way to the pharynx. The epithelium of the pharynx contains large quantities of glandular cells that produce digestive enzymes, and the cilia of the pharynx allow these organisms to digest its food (Enríquez-García et al. 2013). Although these organisms have a small diet, digestion and secretion are often complex.

The ctenophores are bioluminescent, meaning that they naturally glow in the dark due to a unique physical feature that allows them to generate their own light internally. They have two types of reproduction: sexual and asexual. These organisms are able to regenerate almost any part of their body and they can regenerate even half a body. Asexual reproduction occurs when the organism releases small fragments of its body and each fragment is regenerated into a full adult. In the case of sexual reproduction, most of the ctenophores are hermaphrodites and only some species are separate sexes. Pelagic ctenophores expel their gametes through the mouth towards the sea water and that is where fertilization takes place, which can be a self-fertilization or a cross-fertilization (Brusca & Brusca 2003). Later they will become embryos that grow rapidly to be transformed into a plantotrophic larva called a cidipoide. The ctenophores are easily confused with the cnidarians: the development of ctenophores is very different from that of the cnidarians, which have a planula larva, contrary to the cidipoide larva of the ctenophores.

The ctenophores have great ecological importance. The main role of these organisms in the trophic chain is to feed on other groups of marine invertebrates and be an intermediary of some parasites. However, there have also been ecological catastrophes due to these organisms. In 1980 in the Black Sea, two species of ctenophores were accidentally introduced by ballast water. These were large predators of anchovies, and this had a great effect on the Black Sea fishing industry, thus causing the collapse of the anchovy fishing industry. Currently it is not known that other problems could be caused by the absence of the ctenophores. Even though they are such small animals, they have great importance.

The ctenophores have the characteristic of being a large predator, due to their great capacity of reproduction. As a predator of some marine invertebrates, it has a great ecological importance. On the other hand, if its population is not controlled, it can economically affect the fisheries. It is of great importance that the studies of the ctenophores be deeper in order to recognize how it could affect the ecology of other organisms.

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Humpback Whales

 

Essay by García-Velasco Carolina & López-Juarez Nadia Frida (edited by Professor Krista Williams)

Nadia-humpback whale 3Have you ever imagined that a whale could hug you? It sounds impossible, but the humpback whale’s large pectoral fins would allow it to likely embrace not only you, but also your entire house! The humpback whale (Megaptera novaengliae) is the fourth largest whale in the world. It is distributed throughout all the oceans. Due to its large amounts of fat, was hunted intensely until almost going extinct. By data such as its amazing morphology and peculiar behavior, the humpback whale is one of the most interesting marine mammals.

The Megaptera novaengliae whale is the fourth largest whale in the world (Frisch-Jordan 2014) commonly referred to as “humpback whale”, because when diving, it arches its back sharply showing its prominent dorsal fin, generating the impression of a hump (Frisch-Jordán 2014). It is characterized by have long pectoral fins, which can measure up to a quarter of the total length of its body (Guerrero-Ruíz et al. 2006, Niño-Torres et al., 2011, Frisch-Jordán 2014). Its dorsal coloration is black, while the ventral can vary in shades ranging from black to white (Niño-Torres et al., 2011). They get to measure from 13 m to 18 m and weigh 30 t to 40 t, the females being larger than males (Guerrero-Ruíz et al., 2006; Niño-Torres et al., 2011). By such dimensions it is considered to be one of the largest animals in the entire ocean.

The humpback whale distribution is influenced by the seasons of the year: in autumn and winter it is distributed in tropical and subtropical waters, where baby whales grow and adult whales breed; while in spring and summer they inhabit zones of temperate-cold climate where they feed (Guerrero-Ruíz et al., 2006; Niño-Torres et al., 2011; Frisch-Jordán, 2014). In Mexico they are seen in the Peninsula of California to the coast of Chiapas at the beginning of December until the end of April (Niño-Torres et al., 2011), where, as mentioned, in this area the breeding and reproduction is carried out. The breeding is carried out only by the females and the baby whales remains at their side until 11 months. In terms of reproduction, males perform vocalizations called songs to attract females (Guerrero-Ruíz et al., 2006). This way of life is perhaps the one that has helped them to dominate the oceanic waters until today.

These whales possess large amounts of fat and were therefore hunted intensely, which caused their population to decrease drastically (Urbán & Aguayo 1987, Guerrero-Ruíz et al. 2006, IWC 2018). As a consequence, the International Whaling Commission in 1995 prohibited its commercial capture (Guerrero-Ruíz et al 2006, IWC 2018). In Mexico, the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) catalogs humpback whales in Appendix I (CITES 2016), while under the standards it is under special protection in NOM-059-SEMARNAT-2010 (DOF 2010), and in NOM-131-SEMARNAT-2010, in addition to an agreement that establishes a refuge area of protection for large whales the marine areas that are part of the national territory (DOF 2002). As a result of these rules and laws of protection, it has been possible to preserve the species of humpback whale.

In conclusion, the humpback whale is unique because of its large size and is an important species for being the only one that has such large pectoral fins, in addition to its behavior and strategies that have allowed it to dominate the oceans. The preservation of this species has been made possible with the help of laws and norms generated for their protection. We believe that it is important for these organisms to continue being studied in order to contribute more to their conservation until their total population recovery is achieved.

References:

CITES. Convención sobre el Comercio Internacional de Especies Amenazadas de Fauna y Flora Silvestres. Apéndices I, II Y III. Consultado el 14 de enero de 2019: https://cites.org/esp/app/appendices.php

DOF. Diario Oficial de la Federación. 2002. Acuerdo de área de refugio para proteger grandes ballenas de los subórdenes Mysticeti y Odontoceti. Secretaría de medio ambiente y recursos naturales. Consultado el 14 de enero de 2019: http://dof.gob.mx/nota_detalle.php?codigo=733639&fecha= 24%2F05%2F2002

DOF. Diario Oficial de la Federación. 2010. Norma Oficial Mexicana NOM-059-SEMARNAT-2010, Protección ambiental-especies nativas de México de flora y fauna silvestre-Categorías de riesgo y especificaciones para su inclusión, exclusión o cambio-Lista de especies en riesgo. Secretaría de medio ambiente y recursos naturales. Consultado el 14 de enero de 2019: http://www.profepa.gob.mx/innovaportal/file/435/1/NOM_059_SEMARNAT_2010.pdf

DOF. Diario Oficial de la Federación. 2011. Norma Oficial Mexicana NOM-131-SEMARNAT-2010, Lineamientos y especificaciones para el desarrollo de actividades de observación de ballenas, relativas a su protección y la conservación de su hábitat. Secretaría de medio ambiente y recursos naturales. Consultado el 14 de enero de 2018: http://www.dof.gob.mx /nota_detalle.php?codigo=5214459&fecha=17/10/2011

Frisch-Jordán A. 2014. Capítulo 9. Siguiendo a las ballenas jorobadas: catálogo de fotoidentificacion FIBB. Pp: 172-189 In: Cifuentes-Lemus J. L. & F. B. Cupul-Magaña. Temas sobre investigaciones costeras. Universidad de Guadalajara, México.

Guerrero-Ruíz, M., J. U. Urbán-Ramírez & L. Rojas-Bracho. 2006. Las Ballenas del Golfo de California. Instituto Nacional de Ecología (INE-SEMARNAT), México 524 pp.

IWC. International Whaling Commission. 2018. A brief of the ‘Status’ of whale populations, International Whaling Commission. Consultado el 14 de enero de 2019: https://iwc.int/status.

Niño-Torres, C.A., J. Urbán-Ramírez & O. Vidal. 2011. Mamíferos Marinos del Golfo de California: Guía ilustrada. Publicación especial No. 2, Alianza WWF México-Telcel. 192 pp.

Reilly, S. B., J. L. Bannister, P. B. Best, M. Brown, R.L. Brownell Jr, D. S Butterworth, P. J. Ckapham, J. Cooke, G. P. Donovan, J. Urbán & A.N. Zerbini. 2008. Megaptera novaeangliae. The IUCN Red List of Threatened Species 2008. Consultado el 14 de enero de 2019: http://www.iucnredlist.org/details/ 13006/0.

Urbán, J. & A. Aguayo. 1987. Spatial and seasonal distribution of the humpback whale, Megaptera novaeangliae, in the mexican Pacific. Marine Mammal Science 3(4): 333-344.

Sea Otters: A Key Species in Biodiversity

Essay by Emma Yesenia P.R. (edited by Professor Krista Williams)


Sea otters are extremely tender animals that undoubtedly draw attention because of their faces and the ways in which they behave. The otters, despite being very small, have impressive behaviors. Their feeding, reproduction, behavior and adaptations are features that catch people’s attention. Less known to most people is their importance in maintaining a healthy, balanced ecosystem.

The behavior or of the otters is diurnal. That is to say, they are more active in the day. Often, they are seen spinning or covering their faces. This is because they bathe most of the time. They reproduce in the spring. Male otters can be aggressive and when they are reproducing, they make similar sounds to birds when the young are born.  When the offspring are born, the mother has to take care of them because they do not yet have the full coat to float. It takes eight to twelve months for a baby to grow its full coat. When a baby otter is orphaned, other otters adopt it so that it does not die of hunger. It has been observed that many otters suffer when they see their young die, and they often carry the young until they begin to decompose. Although this kind of empathy is characteristic of human behavior, it is found in sea otters.

Marine otters inhabit the North Pacific, from northern Japan to Baja California in Mexico. They live on the coasts to facilitate their search for food. Among their prey are sea urchins, mollusks, crustaceans and some fish. Sea otters use rocks to open the shells and some of their prey. This makes them one of the few mammals that uses tools.

In most of its distribution area, it is considered a “key species” due to the control it exerts on the population of sea urchins, which would otherwise cause extensive damage to the ecosystem of seaweed forests such as kelp, because urchins feed on the bottom of algae stems, causing algae to die. The loss of habitat and nutrients provided by algae forests create a barren environment in the sea. The role of this species as protector of algae forests is more evident in open coasts than in bays and estuaries.

Sea otters, in addition to being tender animals, are extremely important for the care of marine forests and for increasing biodiversity. We must protect sea otters from fishermen or people who consider otters to be an enemy because they compete with them for their food. We should take care of this valuable species, because sea otters play such a valuable role in ecosystem biodiversity.

Climate Change Catastrophe: A Lost Cause

Essay by Jorge Eduardo M.L., student of Marine Biology at Universidad del Mar, Oaxaca, Mexico (edited by Professor Krista Williams)

The critically endangered vaquita marina is a species of porpoise endemic to the Gulf of California that is on the brink of extinction.

The extinction of animal and plant species around the world due to climate change has a significant impact on humanity. Life on earth depends on animals and plants living in harmony within a healthy ecosystem. Throughout history, the loss of animals has occurred naturally: mass extinction, meteorites, glacial times, natural catastrophes: About 252 million years ago, 90% of the species on Earth were wiped out due to an abrupt rise in global-average temperature. While there is life, there is death.

We humans are writing our own death sentence. Excess consumption, too many cars, pollution, garbage, etc. have all contributed to climate change, and we are now facing a global catastrophe. In 2014, a scientist concluded that “equilibrium temperature increase predicted as a result of current concentration of atmospheric greenhouse gasses is already over 5°C.” Global warming, droughts, natural disasters and a rise in sea levels all threaten our existence on this planet.

In my opinion, climate change is too serious a problem; we’ve come to the point of no return. I think it is too late to save the animals, and I feel it is a waste of time to try. Humans and all governments promise to save animals, but nobody can really do anything about the catastrophe at hand. Before, I hoped to do something about it. Maybe this is one of reasons why I chose to major in Marine Biology.

Humans treat nature like a slave—a resource for our indiscriminate consumption—and I don’t know why people can`t just be truthful and admit it. While I don’t care about saving animals anymore, I simply contemplate the beauty while it lasts.

Daily, we see news about animals in danger of extinction, but the people don’t want to hear and instead continue to kill animals without guilt. The promises sound so noble, but they are stupid, empty promises and this makes me conclude that I don’t care anymore about saving the animals as most of my classmates do. I believe it is a lost cause.

Climate change is a death sentence that we ourselves have caused. We will die alongside the animals. It will be catastrophic. The damage caused by climate change is scientifically too grievous for humans to repair. We can try to take corrective measures, like riding bikes, clean energy, reducing our resource consumption, but the climate change will continue to spiral out of control, and we can’t stop it. Gradually, climate change will bring about an apocalypse from which none of us can escape.

Humans are an infection on this planet; we destroy the biodiversity that would otherwise exist naturally. What do we do when we have an illness? We kill the bacteria because the infection must die. But, maybe we should die. Part of me say yes, we should, and sometimes I can’t agree with the efforts to save the human species.

I don’t know how, but I believe that new species of little insects and bacteria could originate after a mass extinction of humans as a result of climate change, because these new organisms will be able to evolve speedily. We humans dedicate our efforts to creating more resistant bacteria, and eventually this will cause our own death due to widespread disease. As global temperatures rise, bacteria and viruses can evolve and become more threatening to humans. Every day, nature is at work, building our chaos. It’s only a matter of time.

Our new logo—una nueva imagen!

TheFarmSchool2group shotSomos un centro comunitario de aprendizaje para desarrollar habilidades de una forma práctica para cuidarnos a nosotros mismos, cuidar el medio ambiente, y cuidarnos unos a otros.

We are an experiential community learning center that teaches practical skills for caring for ourselves, each other, and the land.

La misión es cultivar los talentos de cada individuo dentro de una comunidad auto-sustentable.

Our mission is to cultivate the talents of each individual within the context of a self-sustainable community.

La visión es formar una red de comunidades auto-sustentables que apoya la salud de la gente y de la tierra.

The vision is to form a network of self-sustainable community centers that support the health of the people and the land.

Los principios básicos son (1) la salud del cuerpo, mente, y espíritu y (2) auto-sustentabilidad

The basic principles are (1) physical, mental, and spiritual health and (2) self-sustainability.

Our unique approach to education

Download Feb 2012 418An authentic educational environment nurtures, nourishes and prepares children for a healthy, vibrant lifestyle. As facilitators, the adults are role models for younger people, and everyone is entitled to wholesome food and a healthy balance of work, play and rest.

It is natural to rest after eating a mid-day meal, the way a dog or cat curls up after being fed. Sending children off to recess immediately after lunch prevents proper digestion and absorption of nutrients. This is just one example of the many ways that mainstream education engenders unhealthy habits and maladaptive behaviors.

Let’s consider a unique approach: An authentic educational environment provides people with knowledge, engenders wisdom and prepares children to be healthy, vibrant human beings within communities that steward the earth.

You might ask, “But how does this prepare kids for the real world—the workplace—where you have to be on a tight schedule?”

It is understandable that we adults may be resistant to the idea that anything could change, because we’ve been entrenched in the only world we know from decades ago. But that’s not the world we live in today, and it’s not the world we will live in in the future: Corporate jobs with benefits are rapidly disappearing, thereby making the factory-model education system meant to prepare people for these jobs obsolete as well. The infinite growth “gravy train” is increasingly defunct and irrelevant.

The healthy, vibrant workplaces of the future are self-sustaining communities on arable land where people are wisdom-keepers, working for none other than a divinely inspired mission.

Preparing our children for the future

Children at N.Y. Zoo (LOC)

Children at N.Y. Zoo (Photo credit: The Library of Congress)

The jig is up: parents cannot reasonably expect that their children will enjoy the same kind of lifestyle that they themselves did. The generation that is now approaching retirement borrowed from the future generations—the children who are on the planet today—in order to have the infinite growth lifestyle that they’ve enjoyed up to now. But we can no longer consume resources the same way we did in the past.

We have surpassed peak oil, a concept first coined by the Shell Oil geologist M.K. Hubbert. He was the first to predict that once Peak oil was reached, there would be massive public unrest around the world. We’ve well surpassed that point. Not only do we see rapid, alarming changes on a sociopolitical level, but the impact of climate change on our living ecosystems is undeniable.

We can respond to these rapid changes by making better and different choices than we did in the past. We can teach our children sustainable living skills that allow them to live in community, close to the Earth, doing work that directly improves the quality of life on the planet as well as their physical, mental, emotional and spiritual well-being. It is up to us to prepare our children.