Klasifikasi dan ciri-ciri Chordata, klasifikasi, ciri-ciri dan hubungan

kekerabatan Vertebrata

GENERAL CHARACTERISTICS:

• BODY SIMMETRY : BILATERAL

• COELOM

• TRIPOBLASTIC

• DIGESTIVE SYSTEM COMPOSES MOUTH, ESOPHAGUS, STOMACH, INTESTINE, ANUS

• DEUTEROSTOMIA

PHYLUM CHORDATA

• REPRODUCTION SYSTEM: SEXUAL (MOSTLY) AND ASEXUAL (SOME UROCHORDATE)

- Notochord

- Dorsal nerve cord

- Pharyngeal gill slits / Pharyngeal pouch

- Post-anal tail.

DEFINING CHARACTERISTICSPHYLUM CHORDATA

These attributes are always found in the larval forms or early embryo (although they may be absent in the adult).

• The notochord is mainly composed of fibrous connective tissue

• For those animals in which it persists into the adult form, the notochord provides support (it acts like our backbone) and increases swimming efficiency

• In animals like ourselves, bony structures called vertebrae develop near the notochord and eventually replace it during embryogenesis

1) The Notochord

2) Pharyngeal Gill Slits

• Pharyngeal gill slits are cuts in the pharynx that connect to a cavity surrounding the pharynx

• For organisms in which they remain in the adult, they are often elaborated into respiratory structures (and are sometimes involved in filtering food during feeding).

• The morphological equivalent of gill silts are seen briefly during our own development (weeks 4-5), but they usually close or develop into other structures

3) The Postanal Tail

• In all the phyla we have studied up to this point, the anus was terminal (at the tip of the tail)

• Chordates, on the other hand, follow the anus with a tail of variable length (again, an adaptation for locomotion).

• In us, the tail is short and fused (the coccyx at the base of your spine).

4) Hollow Dorsal Nerve Cord

• Our nerve cord, like that of other chordates is hollow (even in the adult).

• Well, what else is there to say?!?!?

Let’s start at the very beginning . . .

• Phylum Chordata is divided into three subphyla:

– Subphylum Urochordata– Subphylum Cephalochordata– Subphylum Vertebrata

Subphylum Urochordata (Tunikata)

Defining Characteristic :

• Notocorord and dorsal nerve cord present only in larval stage, being reabsorbed at metamorphosis

Contoh: Molgula sp.

General featuree

• Reproduction: sexual and asexual (Thaliacea)

• Excretory system: Mostly (diffusi) some have specialized organ (renal sacs, renal vessicles)

• Nerve system composes of brain and cerebral ganglion

Subphylum Urochordata

• At first glance, you might mistake this creature for a sponge.

• Adult tunicates look like small sacs (about 3 cm tall) and are stationary, lacking a nerve cord, a notochord, and a post-anal tail.

• Lacking three of the four distinguishing hallmarks of the chordates, it would seem impossible for these animals to be placed in phylum Chordata.

Subphylum Urochordata

• However, tunicates begin life in a larval state, which have a post-anal tail, a nerve cord, and a notochord.

• Therefore, these

immobile animals with tadpole-like larvae are considered chordates.

Subphylum Urochordata

• Urochordates have a notochord that extends from just behind the tail to the head (rather than from head to tail; Urochordata means "tail-cord")

• Many urochordates are more commonly referred to as “sea squirts”

Subphylum Urochordata

• The body of an adult tunicate is quite simple, being essentially a sack with large gill structures that form two siphons through which water enters and exits. Water is filtered inside the sack-shaped body.

Defining Characteristics : Notochord and nerve cord are found along

entire length of body and persist throughout the life cycle;

The notocord is contractile, composed of longitudinal series of flattened disc containing myosin

Example:Amphioxus sp.

Subphylum Cephalochordata

Subphylum VertebrataDEFINING CHARACTERISTICS

• Vertebral column, or a chain of bony elements (vertebrae). The vertebral column more or less replaces the notochord as the chief "stiffener" of the body in locomotion.

• Cranium (brain case)• Mostly possess paired appendages and

limb girdle

Subfilum Vertebrata

Ciri-ciri :

1. Bony or cartilaginous vertebrae (columna vertebralis) surrounding spinal cord; notochord in all embryonic stages, persisting in some of the fish

Notocord

Basiodorsal

Basioventral

Interdorsal

Interdorsal

Spinal cord

Spinal cordAgnata

Gnatostomata

Basiodorsal

Karakter lain yang dimiliki oleh Vertebrata

2. Dua pasang anggota badan

3. Modifikasi kulit menjadi sisik, bulu dan rambut

4. Selom yang berisi organ2 visceral

5. Skeleton dalam (endo skeleton) yang terdiri dari skeleton utama (aksial) dan skeleton tambahan (apendikular)

6. Sistem peredaran darah tertutup dengan jantung bersekat (atrium dan ventrikel) dan pembuluh darah

8. Sistem respirasi dengan paru-paru atau insang

9. Sistem ekskresi dengan unti fungsional nefron.Sistem ini berhubungan dekat dengan sistim reproduksi dan menggunakan saluran bersama

10. Relatively large brain plus a unique set of sensory and motor cranial nerves;

Klasifikasi vertebrata

Superclass Agnata - Class Myxini - Class CephalaspidomorphiSuperclass Gnatostomata - Class Chondrichthyes - Class Sarcopterygii - Class Actinopterygii

Class Amphibia Class Reptilia Class Aves Class Mamalia

Klasifikasi ini disusun berdasarkan Nelson (1994), Zug (1993), Ernst & Barbour (1989), Wilson & Reeder (1993)

Sometime both classes were combined into a Class Osteichthyes

Evolusi Vertebrata