Urochordata & Cephalochordata

Summary

Proto chordates, an informal group including subphyla Urochordata and Cephalochordata, are closely related to vertebrates despite being invertebrates. Urochordata, known for sessile tunicates and the predatory Didemnum, are filter feeders with some forming massive colonies. Cephalochordata, represented by amphioxus, have fish-like bodies. Both reproduce asexually and sexually, avoiding self-fertilization for genetic diversity. Tunicates, like the edible sea pineapple, feature in Asian cuisine, while Didemnum is invasive in the US, impacting ecosystems.

Takeaways

• 🐟 Protochordates are an informal group closely related to vertebrates, despite being invertebrates.
• 🌊 Subphylum Urochordata includes tunicates, which are sessile filter feeders, while Cephalochordata includes the amphioxus, which have fish-like bodies.
• 🌿 Tunicates can reproduce both sexually and asexually, with the latter often occurring through budding.
• 🔍 There is a predatory tunicate species that feeds on small marine animals using a hood-like mouth.
• 🌐 Colonial tunicates, known as pyrosomas, can form massive structures up to 60 feet long.
• ⚠️ Invasive tunicate species have impacted ecosystems in the United States by suffocating native species with dense coverings on the ocean floor.
• 🍣 The sea pineapple, an edible tunicate, is part of Korean and Japanese cuisine and is known for its combination of four tastes.
• 🥗 Pirarucu, or 'pure' in Spanish, is a type of tunicate used in Chilean and Peruvian cuisine, noted for its slightly bitter, soapy flavor.
• 🍤 Lance lips, often mistaken for small fish, are fried in Southeast Asian cuisine.
• 🔬 All protochordates exhibit the core characteristics of the phylum Chordata at some life stage, with amphioxus being the only ones to show all traits as adults.
• 🧬 Both urochordates and cephalochordates are considered close relatives to vertebrates, providing insights into the common ancestry of the cranium.

Q & A

What is the significance of the term 'proto chordates'?

Proto chordates is an informal group that includes the subphyla Echinodermata and Cephalochordata, suggesting their close relation to vertebrates despite being invertebrates.

What are the two subphyla included in the proto chordates group?

The two subphyla included in the proto chordates group are Echinodermata and Cephalochordata.

What types of organisms are part of the subphylum Echinodermata?

The subphylum Echinodermata includes organisms such as sea squirts, tunicates, and their larvae.

What is the common name for the subphylum Cephalochordata?

The subphylum Cephalochordata is commonly known as amphioxus or lancelets.

How do tunicates differ from amphioxus in terms of habitat and behavior?

Tunicates are sessile, meaning they are attached to a substrate, while amphioxus have fish-like bodies that they use to burrow in the sand.

What is the primary feeding method of most tunicates?

Most tunicates are filter feeders, collecting small organic particles from the surrounding water.

What is unique about the predatory tunicate species?

The predatory tunicate species is unique as it feeds on small marine animals with a mouth like a hood.

How do colonies of tunicates known as Pyrosoma ohms form and what is their impact on the environment?

Colonies of Pyrosoma ohms form by budding, a form of asexual reproduction, and can create massive structures up to 60 feet long, which can suffocate native species by creating a dense covering along the ocean floor and surrounding surfaces.

What is the reproductive strategy of tunicates?

Tunicates can reproduce both sexually and asexually, with the latter typically occurring through budding and the former involving the release of sperm and eggs into the surrounding water for external fertilization.

Why do tunicates generally avoid self-fertilization?

Tunicates generally avoid self-fertilization to promote genetic variability, which is important for the health and adaptability of the species.

What is the culinary significance of the sea pineapple and how is it typically prepared?

The sea pineapple, an edible tunicate, is part of the culinary palate in Korea and Japan, usually served raw, boiled, or pickled, and is known for combining the four tastes of sweetness, saltiness, acidity, and sourness.

How is the tunicate known as 'pirarucu' used in Chilean and Peruvian cuisine?

The tunicate known as 'pirarucu' or 'piye' in Spanish is used in the cuisine of Chile and Peru, where it can be eaten raw or cooked and is said to have a slightly bitter, soapy flavor.

What is the common mistake made when referring to 'lance lips' in Southeast Asian cuisine?

The common mistake made when referring to 'lance lips' in Southeast Asian cuisine is that they are often wrongly called small fish, despite being a type of tunicate.

Why are the proto chordates considered important in the study of vertebrate evolution?

Proto chordates are considered important in the study of vertebrate evolution because they exhibit the four core chordate characteristics at some stage in their life, providing clues to the common ancestry of the craniates.

Outlines

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🐠 Proto Chordates and Their Characteristics

Proto chordates are an informal group that includes two subphyla, Eurychordata and Cephalochordata, which are closely related to vertebrates. Eurychordata encompasses tunicates like ascidians, sea squirts, and their larvae, while Cephalochordata includes the lancelet, also known as amphioxus. Tunicates are sessile filter feeders, but there is a predatory species that feeds on small marine animals. Lancelets have fish-like bodies and burrow in sand. Both groups exhibit the four core characteristics of chordates at some stage in their life, providing insights into the common ancestry of all chordates.

Keywords

💡Proto chordates

Proto chordates refer to an informal group of animals that are closely related to vertebrates but are invertebrates themselves. They include the subphyla Echinodermata and Cephalochordata. In the video, this term is central to understanding the evolutionary connection between these primitive chordates and the development of more complex vertebrate animals. The script mentions that they are grouped together to suggest their close relation to vertebrates.

💡Echinodermata

Echinodermata is a subphylum of deuterostome invertebrates that includes starfish, sea urchins, and sea cucumbers. They are characterized by radial symmetry as adults and a unique water vascular system. In the context of the video, they are part of the proto chordates, highlighting the diversity of life forms within this group and their significance in marine ecosystems.

💡Cephalochordata

Cephalochordata, also known as amphioxus or lancelets, is a subphylum of chordates that are considered to be very close to the evolutionary line that led to vertebrates. They exhibit some chordate characteristics but lack a backbone. The video script describes amphioxus as having fish-like bodies that they use to burrow in the sand, illustrating their unique position in the evolutionary tree.

💡Ascidiacea

Ascidiacea, commonly known as tunicates or sea squirts, are marine invertebrate animals that belong to the phylum Chordata. They are sessile as adults and are filter feeders, collecting small organic particles from the surrounding water. The script mentions tunicates as an example of how proto chordates have adapted to their environment, with some species being predatory and others forming large colonies.

💡Predatory tunicate

A predatory tunicate is a specific type of tunicate that feeds on small marine animals, using a mouth like a hood to capture prey. This is an unusual characteristic among tunicates, as most are filter feeders. The video script highlights this species as an example of the diversity within the tunicate group and the adaptations that have occurred for survival.

💡Colonial tunicates

Colonial tunicates, such as pyrosomids, are a type of tunicate that forms large, interconnected colonies. These colonies can create massive structures in the ocean and are known for their dense covering along the ocean floor. The script uses this as an example to discuss the impact of invasive species on native ecosystems, as they can suffocate native species by covering their habitats.

💡Hermaphroditic

Hermaphroditic refers to organisms that possess both male and female reproductive organs. In the context of the video, it is mentioned that tunicates are hermaphroditic with few exceptions, meaning they can self-fertilize. However, the script also notes that tunicates generally do not self-fertilize, which promotes genetic diversity through cross-fertilization.

💡Asexual reproduction

Asexual reproduction is a mode of reproduction where offspring arise from a single organism without the involvement of gametes (sex cells). In the video, budding is mentioned as a form of asexual reproduction in tunicates, where new individuals grow out of the body of the parent organism, eventually separating to live independently.

💡Sexual reproduction

Sexual reproduction involves the combination of genetic material from two parent organisms to produce offspring. The script describes a sexual means of reproduction in tunicates where both sperm and eggs are released into the surrounding water to fertilize, which is an alternative to budding and contributes to genetic variability.

💡Edible tunicates

Edible tunicates, such as the sea pineapple, are consumed as part of culinary traditions in certain regions, like Korea and Japan. The script mentions that they are served raw, boiled, or pickled and are known for their unique combination of tastes, including sweetness, saltiness, acidity, and sourness.

💡Chordata

Chordata is the phylum to which vertebrates, cephalochordates, and tunicates belong. They exhibit certain core characteristics at some stage in their life, such as a notochord, a dorsal nerve cord, pharyngeal slits, and a post-anal tail. The script emphasizes that encephalochordates and urochordates are part of this phylum because they show these traits, indicating their close relationship to vertebrates.

Highlights

Proto chordates are an informal group including the subphyla Echinodermata and Cephalochordata, indicating a close relation to vertebrates.

Subphylum Echinodermata includes sea squirts and tunicates, while Cephalochordata includes the lancelet, also known as amphioxus or lampreys.

Tunicates are sessile, whereas amphioxus have fish-like bodies used for burrowing in sand.

Most tunicates are filter feeders, collecting small organic particles from the surrounding water.

There is a predatory tunicate species that feeds on small marine mammals with a mouth-like hood.

Colonial tunicates, known as pyrosomas, can form structures up to 60 feet long.

Invasive tunicate species have impacted ecosystems in the United States by suffocating native species with dense ocean floor coverings.

Tunicates can reproduce both sexually and asexually, with hermaphroditic colonies forming through budding.

Sexual reproduction in tunicates involves releasing both sperm and eggs into the surrounding water for fertilization.

Tunicates generally do not self-fertilize, leading to greater genetic variability.

Amphioxus reproduces only sexually, with a spawning process similar to that of fish, where fertilization occurs in surrounding waters.

The sea pineapple is an edible tunicate enjoyed in Korean and Japanese cuisine, combining sweetness, saltiness, acidity, and sourness.

Pirarucu, called 'pure' in Spanish, is a tunicate found in Chilean and Peruvian cuisine, known for its slightly bitter, soapy flavor.

Lance lips are a part of Southeast Asian cuisine, typically fried in a batter and often mistakenly referred to as small fish.

Urochordata and Cephalochordata are part of the phylum Chordata, exhibiting the four core chordate characteristics at some life stage.

Tunicates have a characteristic tadpole-like larvae, and lancelets are the only chordates to exhibit all four traits in their adult form.

Both urochordates and cephalochordates are considered close relatives to vertebrates, providing insights into the common ancestry of the cranium.

Transcripts

proto chordates are an informal group

that includes the subphyla euro Chordata

and cephalic or Dada they are grouped

together to suggest their close relation

to vertebra although both subphyla are

invertebrates subphylum euro Chordata

includes the Citians sea squirts and

tunicates larvae seein's

and fali ACN's encephalo Chordata

includes the Braccio stella also known

as amphioxus or lampsilis tunicates are

sessile while amphioxus have fish-like

bodies that they use to burrow in the

sand

most tunicates are filter feeders

collecting small organic particles from

the surrounding water there is one

species of tuna kitt known as the

predatory tuna kit that feeds on small

marine mammals with a mouth like hood

colonial two deacons known as Pyro's

ohms can form together to create massive

structures up to 60 feet long

certain invasive species have found

their way to the United States the

colonies create a dense covering along

the ocean floor and surrounding surfaces

suffocating native species that are

essential to ecosystems tunicates are

able to reproduce both a sexually and

sexually and they are with few

exceptions hermaphroditic colonies

typically formed through budding a form

of asexual reproduction an alternative

to budding is a sexual means of

reproduction in which both sperm and

eggs are released into the surrounding

water to fertilize tunicates as a rule

do not self fertilize and therefore this

mode of reproduction produces greater

genetic variability plantlets reproduce

only sexually in a very similar spawning

process as the Yi recordings in which

fertilization takes place in the

surrounding waters the sea pineapple is

an edible acid' en that is part of the

culinary palate in Korea and Japan it is

usually served raw boiled or pickled and

is said to combine the four tastes

sweetness saltiness acidity and sourness

pirate chilensis called puree in Spanish

is a tunic it found in the cuisine of

Chile and Peru it can be eaten raw or

cooked and is said to have a slightly

bitter soapy flavor Lance lips are found

among Southeast Asian cuisine typically

fried in a batter there generally and

wrongly referred to as small fish gyro

Chordata encephalo Chordata are a part

of the greater phylum Chordata because

they exhibit the four core date

characteristics at some stage in their

life tunicates have a characteristic

tadpole

larvae and landslides are the only core

date to exhibit all four chordate traits

in the adult form both the uro chordates

and cephalic chordates are thought to be

very close relatives to the vertebrates

and give many clues to the common

ancestry of the cranium

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