reptile

Introduction
- Focus on physiology and anatomy of fish and reptiles.
- Importance for clinical applications in farming and reproduction.

Variability among species
- Physiological and anatomical differences.
Effect of husbandry and diet on sexual maturity.
- Size, diet, and husbandry impact maturity rate.
- Cannot force sexual maturity through diet or conditions.
Seasonal breeding in reptiles
- Dependent on external factors: temperature, humidity, food availability.
- Temperate climates: breeding typically in spring/summer.
- Tropical climates: breeding in wet seasons.

Testicles are internal (intra-abdominal).
- Differences based on species.
- Right testicle is cranial to the left in most species.
Lack of accessory glands in many reptiles.
- Presence of seminal segments in kidneys for some reptiles.
Hemipenes in certain snake species.
- Dual hemipenes for mating.
- Retraction of hemipenes into a sac until mating.
- Keratinized spines may be present for attachment during copulation.
Clinical implications of mating behaviors.
- Hemipenile plugs can form in non-reproductive males leading to infection.

Ovaries and oviducts present in both sides.
- Soft-shelled eggs; General anatomy similar to birds but different physiology.
Clutch size variability
- Ranges from 6-12 eggs, up to 100 in marine turtles.
Eggs produced and stored until conditions are optimal for laying.
- Eggs laid through cloaca, which combines urinary, reproductive, and gastrointestinal tracts.
Gestation and incubation durations vary significantly.
- Typical 1-2 months; longer in certain species.

Stages of oocyte and follicle development.
- Previtellogenic and vitellogenic stages.
- Cycle involves ovulation, fertilization in cranial oviducts.
Oviparous vs. viviparous reproduction
- Oviparous: laying eggs to develop outside.
- Viviparous: live birth, some species allow for hatching inside.
Parthenogenesis: female reproduction without fertilization.
- Seen in isolated species (e.g., Komodo dragons).

Reproductive hormones similar to mammals/birds (e.g., FSH, LH) but vary by species.
External factors critically influence hormone functionality.
- Key influences: day length, temperature, humidity.
Sexual segment development in male reptiles during breeding season.

Male reproductive behaviors (anxiety, seeking females).
Environmental triggers for female laying eggs (need for nesting sites).
- Absence of proper nesting conditions can lead to egg retention (dystocia).

Follicle stasis causes health implications due to lack of ovulation.
Sex determination genetics vs. temperature-dependent sex changes.
Genetic determination: ZZ for males and ZW for females.
- Temperature impacts developmental sex in several reptile species.

Both ovaries and testicles located dorsally, with varying sizes.
- Ovaries contain numerous smaller eggs (follicles).
External fertilization is prevalent across species.
Egg development in fish does not result in fertilization until eggs are laid.

Variability in reproductive cycles based on species, environment, and conditions.
Gestation can vary greatly.
Some species may exhibit viviparity (live births).
- Examples include certain sharks.
- Ovoviviparous species have eggs that hatch internally.

Reproductive hormones, including GTH1 and GTH2, similar functions to FSH and LH.
External conditions (temperature, currents, moon phases) critically affect fish breeding strategies and success.

Knowledge of species-specific reproductive physiologies is essential for effective clinical and breeding practices in reptiles and fish.
Environmental and hormonal interactions play critical roles in reproductive success and challenges faced within species.