Endocrinology of Aquatic Animals

Code:

RM25

Acronym:

EAA

Keywords
Classification	Keyword
OFICIAL	Marine Biology and Ecology

Instance: 2025/2026 - 2S (of 16-02-2026 to 31-07-2026)

Active?	Yes
Responsible unit:	Microscopy
Course/CS Responsible:	Master Degree in Marine Sciences - Marine Resources

Cycles of Study/Courses

Acronym	No. of Students	Study Plan	Curricular Years	Credits UCN	Credits ECTS	Contact hours	Total Time
MCMRM	3	Oficial Plan 2018	1	-	5	50	135

Teaching language

Suitable for English-speaking students

Objectives

The endocrinology of aquatic organisms focuses on the study of hormonal systems that regulate essential physiological processes such as sexual differentiation, growth, reproduction, and osmoregulation. These systems are highly sensitive to environmental changes, including climate change and other sources of environmental stress.

In a global context of rapid environmental change, it is crucial to understand how aquatic organisms use their endocrine systems to maintain homeostasis, adapt, and respond to shifting external conditions. Thus, the main objectives of this course unit are:

• To study in depth the central hormonal axes of various groups of aquatic organisms (fish, amphibians, mollusks, crustaceans, among others), with a focus on physiological and cellular mechanisms governing processes such as metamorphosis, gonadal development, ion regulation, and reproductive behavior.




• To analyze the effects of climate change — including rising water temperatures, ocean acidification, shifts in salinity, and oxygen availability — on endocrine regulation, emphasizing an integrative approach that combines comparative physiology and ecophysiology.




• To understand the interactions between environmental cues and hormonal modulation, including how environmental stressors (e.g., seasonal fluctuations, extreme events) interfere with neuroendocrine coordination and reproductive success.




• To develop skills to interpret endocrine responses as physiological indicators of environmental health, enabling functional assessment of hormonal adaptations in altered aquatic environments.




• To promote the application of endocrine knowledge in environmental conservation and management, preparing students to contribute to ecological monitoring projects and aquatic biodiversity preservation.

By the end of the course unit, students will be able to critically analyze the relationship between the environment and hormonal physiology in aquatic organisms, clearly distinguishing between natural adaptive mechanisms and those arising from persistent environmental stress, contributing to a systemic and preventive approach to the protection of aquatic ecosystems.

Learning outcomes and competences

Understand the mechanisms by which the endocrine system of aquatic organisms regulates adaptive physiological responses to environmental changes, including both natural fluctuations and disturbances induced by climate-related factors.

Apply knowledge of aquatic endocrinology to practical problem-solving, particularly in areas such as aquaculture production, biomonitoring programs, migration studies, and ecological interactions between species.

Develop research and critical thinking skills by gathering, selecting, analyzing, and interpreting relevant scientific information in the field of aquatic endocrinology and physiology.

Enhance the ability to communicate scientific information clearly, logically, and in an integrated manner, using schematic representations and connecting new knowledge with previously acquired concepts from complementary areas.

Working method

Presencial

Pre-requirements (prior knowledge) and co-requirements (common knowledge)

Biology and Biochemistry

Program

1. Introduction to Aquatic Endocrinology

• General principles of hormonal signaling and endocrine regulation in aquatic organisms.
• Role of the endocrine system in maintaining homeostasis and responding to environmental factors.

2. Major Endocrine Glands and Axes

• Pituitary gland: organization, regulation, and its central role in endocrine axes
• Pineal gland: photoperiodism and biological rhythms in aquatic environments
• Thyroid gland (or homologous structures in invertebrates): regulation of metabolism and development
• Interrenal glands and endocrine kidney: stress response axes and ionic/metabolic regulation
• Ultimobranchial gland: function and relevance in bony fish

3. Hormones and Specific Physiological Functions

• Sex steroids and sexual differentiation: development of ovaries and testes
• Growth hormone (GH) and insulin-like growth factor (IGF): somatic growth and environmental regulation
• Neuroendocrine axes and reproductive modulation

4. Reproductive Endocrinology

• Hormonal mechanisms controlling reproduction in fish
• Environmental influences on reproductive cycles: temperature, salinity, photoperiod, and other factors

 

Mandatory literature

Several; Encyclopedia of Fish Physiology, Editors Sarah L. Alderman, Todd E. Gillis, Academic Press, 2024. ISBN: 9780323908016

Complementary Bibliography

George Hadwin; Fish Endocrinology, Sofronios E. Papoutsoglou (Editor), 2017. ISBN: 978-9386314567

Comments from the literature

Will also be used scientific articles provided by the responsible course

Teaching methods and learning activities

This course unit adopts a constructivist approach, placing the student at the center of the learning process. Teaching is designed to promote intellectual autonomy, critical thinking, and problem-solving skills.

Students are encouraged to formulate questions, develop hypotheses, engage in evidence-based reasoning, and draw their own conclusions through the analysis and interpretation of presented information. Both theoretical and practical challenges will be introduced during classes to stimulate active participation, peer collaboration, and the integration of prior knowledge with new content.

This method aims not only at knowledge acquisition but also at the development of scientific and communication competencies, preparing students to tackle real-world situations in research, environmental management, or aquatic biodiversity conservation.

Evaluation Type

Distributed evaluation with final exam

Assessment Components

Designation	Weight (%)
Exame	60,00
Trabalho laboratorial	40,00
Total:	100,00

Amount of time allocated to each course unit

Designation	Time (hours)
Estudo autónomo	85,00
Frequência das aulas	50,00
Total:	135,00

Eligibility for exams

Present for three-quarters of classes taught.

Calculation formula of final grade

Assessment Method

Continuous assessment with final exam.

Grading formula:

Final grade = Final theoretical exam score (60%) + Average score of the practical component (40%)

A minimum score of 9.5 out of 20 is required in each component to pass the course.

Special assessment (TE, DA, ...)

Student workers, association leaders and other students with special status will be evaluated similarly to regular students. However, in cases where the law exempts students from failure due to absence from classes, they will be assessed by a final theoretical/practical exam on the content taught in classes in this UC, in which they will have to obtain a minimum grade of 9.5 out of 20.

Final classification = Final theoretical exam grade (100%)

Classification improvement

The improvement of the classification will be obtained in the Final Exam, in accordance with the formula.

Final grade = Final theoretical exam grade (60%) + Average of the classifications obtained in the practical component (40%).

The minimum grade for each component is 9.5 in 20.