BIO 358 1st Edition Lecture 1Outline of Last Lecture I. N/AOutline of Current Lecture II. Who are marine mammalsA. Definition of marine mammals B. Monophyletic cladesIII. What do marine mammals have in common?A. Anatomical SpecializationsB. Physiological specializationsIV. Human impacts on marine mammalsA. indirectB. directV. Current events VI. Example exam question for assignment Current LectureWho are marine mammals?Definition: a functional descriptor of a diverse assemblage of distantly related mammals that spend some or all of their life in a marine (or aquatic) environment. Not an evolutionary valid grouping NOT a monophyletic cladeMonophyletic clade = group that contains an ancestor and all of it’s descendants What do they have in common? Anatomical Specializations: 1) body streamlining a. fusiform body shapeThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.b. reduced protuberancesi. genitalia not outc. modification of limbs 2) Reduced or modified appendagesa. Pectorals = flippersb. Pelvic = often reduced or absentc. Fully aquatic orders = absent 3) Enhanced insulation:a. Blubberb. Fur 4) Large body size – hallmark of being a marine mammal a. Ones with the largest body size are fully aquaticb. Achieved with buoyancy supporting body mass and reduced gravity Physiological specializations:1) Enhanced breath-hold capabilities = apnea a. Dive up to 2 hours2) Specialized thermoregulatory capabilities and vascular structuresa. Cold water, heat sucked 25 times faster3) Specialized sensory systems: a. The ocean is a dark place Vulnerability to indirect human impacts on marine ecosystems: - Habitat degradation and/or destruction (especially for river, estuarine and coastal species) - GLOBAL CLIMATE CHANGE: climate change is affecting the animals we are talking about- Anthropogenic toxins = negatively impact health and/or reproductive success- Other forms of pollution: terrestrial runoff, debris, NOISE (sonar and seismic testing) - Incidental or accidental mortalities – vessel strikes and by-catch in fishing operations (pinnipeds, cetaceans and sea otters) - Credible conservation and management requires maintenance of their environmentHistoric and current direct exploitation by humans: - The vequita will be extinct in my lifetime- Stellar sea cow – extinctwithin 30 years of discovery- North Atlantic wright whale – hunted for over 1000 years (4-5000 individuals) Many species are endangered or threatened:- Northern wright whale - endangered- Manatees - endangered- Bottlenose dolphin – threatened Science and Nature = international journals – same week, evolution of cetaceans on the coverMay 2012 – Piaison discovered entire new sensory system = engulfment feeding Stranding’s – what do they tell us? -long-term data record of global climate change 2001 – DeMaster – by the end of the 21rst century, back to eating marine mammals, over fished other protein out of the ocean2009 – Gerber – should whales be culled to increase fishery yield?! WHAT 2005 – whale deaths linked to navy sonar Global climate change - arctic species that rely on ice for walking and for seals – threatened The worlds rarest whale – mesoplodontraversii – beaked whale – deep diving, 4-5 meters long, describedand discovered in 2012 in New Zealand Example questions?-true false, all living marine mammals are contained within 2 orders of mammals = FALSE